MRI and PET of delayed heavy-ion radiation injury in the rabbit brain

Magnetic resonance imaging (MRI) and positron emission tomography (PET) techniques were used to obtain in vivo scans of delayed (30 GyE helium ion, 230 MeV/u) radiation injury in rabbit brain. T2-weighted (T2W) MRI scans demonstrated alterations that were restricted primarily to the white matter tracts and the deep perithalamic and thalamic regions. Quantitative measurements of T2 and T1 values demonstrated wide variations in absolute values. However, paired comparisons in hemibrain-irradiated rabbits revealed significant increases in T2 (p less than 0.001) and T1 (p less than 0.01) in irradiated versus unirradiated brain. Gadolinium DTPA (GdDTPA) enhanced MRI and 82Rubidium (82Rb) PET detected focal regions of blood-brain barrier (BBB) disruption restricted to the deep white matter and thalamic regions. Sequential GdDTPA enhanced MRI scans showed the spreading of the tracer from the initial site of contrast enhancement. 18Fluorodeoxyglucose (18FDG) PET studies demonstrated the markedly depressed metabolic profiles of irradiated brain. Histological findings of tissue edema and necrosis correlated well with the in vivo imaging abnormalities. These initial studies demonstrate that the irradiated rabbit brain is a suitable animal model for examining the delayed effects of radiation injury in the brain.     

Comparative chromosome and mitochondrial DNA analyses and phylogenetic relationships within common voles (Microtus, Arvicolidae)

The four species of common voles within the genus Microtus – M. kirgisorum, M. transcaspicus, M. arvalis, and M. rossiaemeridionalis – are so closely related that neither morphological features nor paleontological evidence allow clarification of their phylogeny. Analysis of vole karyotypes and mitochondrial DNA sequences, therefore, is essential for determining their phylogenetic relationships. A comparison of high resolution GTG-banding patterns allows us to ascertain the similarity between the karyotypes of these species, revealing that they are composed of rearrangements of the same chromosomal elements. Based on this analysis, we propose possible routes of chromosomal divergence involved in speciation within this group of voles and construct a phylogenetic tree of their karyotypes. We suggest that two different karyotypic variants existed during the course of vole evolution – one resulting in M. rossiaemeridionalis and M. transcaspicus, the other, M. kirgisorum and M. arvalis. As an alternative approach FITCH and KITSCH computer programs were used to construct a phylogenetic tree of vole molecular evolution based on a pairwise comparison of mitochondrial cytochrome b sequences and the divergence time of the species was determined. The correlation between the trees constructed using karyologic and molecular approaches is discussed in the context of other available data.     

Influenza vaccination of human immunodeficiency virus 1-infected patients receiving antiretroviral therapy

In 13 human immunodeficiency virus 1 (HIV-1) infected patients receiving a highly active antiretroviral therapy (HAART) annual influenza vaccination was conducted. It was hoped that HAART would prevent a post-vaccination increase in HIV-1 load and potential adverse effects. Only two patients had an increased viral load on day 14 post vaccination (p.v.). At 6 months p.v., the majority of the patients had a significantly increased CD4 cell count and a significantly decreased viral load. This indicates that HAART can protect patients from adverse consequences of influenza vaccination. The production of antibodies to the influenza A and B viruses in the HIV-infected patients was substantially lower than that in healthy persons. We propose that HIV-positive patients receiving HAART should be subjected to annual influenza vaccination.     

Human papillomavirus infection in relation to mild dyskaryosis in conventional cervical cytology

PURPOSE OF INVESTIGATION: To establish the prevalence and distribution of high-risk human papillomavirus (HPV) genotypes in Slovene women with repeat mild dyskaryosis, and to evaluate three molecular methods for the detection of HPV that could be used as a complementary method to cervical cytology. METHODS: In this prospective study 148 women with three subsequent cervical cytologic tests within two years showing mild dyskaryosis were enrolled. HPV infection was determined using three molecular tests: Hybrid Capture II and two variants of polymerase chain reaction (PCR-PGMY11/PGMY09 and PCR-CPI/CPIIG). RESULTS: HPV was detected in 17 of the 45 women aged < or =30 years and in 21 of the 103 women aged >30 years (37.8% vs 20.4%, p = 0.04). The most common genotype was HPV 16 detected in eight (21.1%) women, the next were HPV 53 and HPV 51, each detected in five (13.2 %) women. The three molecular methods matched in 92.9%. CONCLUSION: Low prevalence of HPV infections indicates that cervical screening programmes in Slovenia are overburdened with mild dyskaryosis. Repeat cytology is not reliable; HPV testing might be useful as a complementary method.     

Graphene oxide quantum dots immobilized on mesoporous silica: preparation,characterization and electroanalytical application

Because of its high surface area and combination of various functional groups, graphene oxide (GO) is currently one of the most actively studied materials for electroanalytical applications. It is not practical to utilize self-supported GO on its own and thus it is commonly integrated with different supporting carriers. Having a large lateral size, GO can only wrap the particles of the support and thus can significantly reduce the surface area of porous materials. To achieve synergy from the high surface area and polyfunctional nature of GO, and the rigid structure of a porous support, the lateral size of GO must essentially be decreased. Recently reported graphene oxide quantum dots (GOQDs) can fulfil this task. Here we report the successful preparation of an SiO₂-GOQDs hybrid, where GOQDs have been incorporated into the mesoporous network of silica. The SiO₂-GOQDs emit a strong luminescence with a band maximum at 404 nm. The Raman spectrum of SiO₂-GOQDs shows two distinct peaks at 1585 cm⁻¹ (G-peak) and 1372 cm⁻¹ (D-peak), indicating the presence of a graphene ordered basal plane with aromatic sp²-domains and a disordered oxygen-containing structure. Covalent immobilization of GOQDs onto aminosilica via such randomly structured oxygen fragments was proven with the help of Fourier transform infrared spectroscopy, solid-state cross-polarization magic angle spinning ¹³C nuclear magnetic resonance, and X-ray photoelectron spectroscopy. SiO₂-GOQDs were used as a modifier of a carbon paste electrode for differential pulse voltammetry determination of two antibiotics (sulfamethoxazole and trimethoprim) and two endocrine disruptors (diethylstilbestrol (DES) and estriol (EST)). The modified electrodes demonstrated a significant signal enhancement for EST (370%) and DES (760%), which was explained by a π–π stacking interaction between GOQDs and the aromatic system of the analytes.

Graphene oxide quantum dots incorporated into a mesoporous silica network have been used as a modifier of a carbon paste electrode for the determination of antibiotics and hormones.     

Giant splenic metastasis due to lung adenocarcinoma

Lung cancer is the most prevalent malignancy in western countries and most of the patients present at advanced stages, but single splenic metastasis is exceptional instead. We report on a case of a seventy-three-year old male presenting with non-hemoptoic productive cough, constitutional syndrome and pain in the left lower quadrant. Physical examination and complementary radiological and hystologycal procedures revealed the presence of an adenocarcinoma of the left lung with probable splenic metastasis. The patient underwent splenectomy, which confirmed the diagnose of splenic metastasis of lung adenocarcinoma and, secondly, lung resection was performed. Topics about lung cancer metastasis are discussed.     

Potential of adenovirus and baculovirus vectors for the delivery of shRNA against morbilliviruses

Morbilliviruses are important pathogens of humans, ruminants, carnivores and marine mammals. Although good vaccines inducing long-term immunity are available, recurrent outbreaks of measles, canine distemper and peste des petits ruminants (PPR) are observed. In control strategies, antivirals thus could be useful to confine virus spread and application of interfering RNAs is a promising approach, provided they can be delivered efficiently into the host cells. We have constructed recombinant adenovirus and baculovirus vectors expressing short hairpin RNAs (shRNAs) against the PPR virus (PPRV) and compared them in vitro. It was found that both recombinant viruses inhibited PPRV replication with the baculovirus vector, which inhibited generation of infectious progeny by more than 2 log10 and the nucleoprotein expression of PPRV by 73%, being the more efficient. The results show that baculoviral shRNA-expressing vectors have the potential for therapeutic use against morbillivirus infections.     

Intravascular papillary endothelial hyperplasia: report of 2 cases and immunohistochemical study

Intravascular papillary endothelial hyperplasia (IPEH) is a benign, nonneoplastic, vascular lesion. The main significance of the lesion lies in the fact that it may be mistaken for angiosarcoma. Oral lesions are uncommon and the present paper reports 2 cases of oral IPEH, in different sites. Histologically, the tissue was characterized by papillary fronds lined by proliferating endothelium. Immunohistochemically (IHC), the lesion was positive for CD34, smooth muscle actin (SMA), type I and IV collagen, vimentin, and laminin, but it was negative for CD105. Local excision was the treatment of choice. No recurrence was observed during a 1-year and 6-month follow-up period, respectively. The clinical, histological, and immunohistochemical characteristics are discussed.     

Lipid peroxidation and antioxidant status in kidney and liver of rats treated with sulfasalazine

Sulfasalazine (SASP) is a drug commonly used in the treatment of inflammatory bowel diseases (IBD). In this study, the changes in endogenous antioxidant capacity and oxidative damage in liver and kidney of SASP-treated rats were investigated. Adult male Sprague–Dawley rats were orally given 0, 300, or 600 mg SASP/kg body weight for 14 days. One half of the animals in each group remained 14 additional days without SASP treatment. At the end of the experimental period, rats were euthanized and liver and kidney were removed. In both organs, the following stress markers were determined: reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and thiobarbituric acid-reactive substances (TBARS). Moreover, histological examination of kidneys showed phagolysosomes after 14 days of SASP withdrawal. A dropsical degeneration was also observed in renal tissue. Oral SASP administration induced a significant increase in TBARS levels in both liver and kidney. After 2 weeks without SASP administration, a recovery of these levels was noted. SOD activity was significantly reduced, while CAT activity significantly increased at 600 mg SASP/(kg day). In kidney, GPx activity significantly increased, while GST activity and GSH levels were significantly reduced at 600 mg SASP/(kg day). These results suggest that in male rats, oxidative damage can be a mechanism for nephro- and hepatotoxicity related with SASP treatment.