Effective Doping of Single-Walled Carbon Nanotubes with Polyethyleneimine

More and more electrically conducting materials are required to sustain the technological progress of civilization. Faced with the performance limits of classical materials, the R&D community has put efforts into developing nanomaterials, which can offer sufficiently high operational parameters. In this work, single-walled carbon nanotubes (SWCNTs) were doped with polyethyleneimine (PEI) to create such material. The results show that it is most fruitful to combine these components at the synthesis stage of an SWCNT network from their dispersion. In this case, the electrical conductivity of the material is boosted from 249 ± 21 S/cm to 1301 ± 56 S/cm straightforwardly and effectively.     

Boron-Rich Boron Carbide Nanoparticles as a Carrier in Boron Neutron Capture Therapy: Their Influence on Tumor and Immune Phagocytic Cells

The aim of the work was to study the interaction between boron-rich boron carbide nanoparticles and selected tumor and immune phagocytic cells. Experiments were performed to investigate the feasibility of the application of boron carbide nanoparticles as a boron carrier in boron neutron capture therapy. Boron carbide powder was prepared by the direct reaction between boron and soot using the transport of reagents through the gas phase. The powder was ground, and a population of nanoparticles with an average particle size about 80 nm was selected by centrifugation. The aqueous suspension of the nanoparticles was functionalized with human immunoglobulins or FITC-labeled human immunoglobulins and was then added to the MC38 murine colon carcinoma and to the RAW 264.7 cell line of mouse macrophages. Flow cytometry analysis was used to determine interactions between the functionalized boron carbide nanoparticles and respective cells. It was shown that B₄C–IgG nanoconjugates may bind to phagocytic cells to be internalized by them, at least partially, whereas such nanoconjugates can only slightly interact with molecules on the cancer cells’ surface.     

Resistin is produced by rat pancreatic islets and regulates insulin and glucagon in vitro secretion

Resistin participates in the regulation of energy homeostasis, insulin resistance, and inflammation. The potential expression in pancreas, and modulation of the endocrine pancreas secretion by resistin is not well characterized, therefore, we examined it on several levels.

We examined the localization of resistin in rat pancreatic islets by immunohistochemistry and immunofluorescence, and the potential presence of resistin mRNA by RT-PCR and protein by Western Blot in these structures. In addition, we studied the regulation of insulin and glucagon secretion by resistin in pancreatic INS-1E β- and InR-G9 α-cell lines as well as isolated rat pancreatic islets.

We identified resistin immunoreactivity in the periphery of rat pancreatic islets and confirmed the expression of resistin at mRNA and protein level. Obtained data indicated that resistin is co-localized with glucagon in pancreatic α-cells. In addition, we found that in vitro resistin decreased insulin secretion from INS-1E cells and pancreatic islets at normal (6 mM) and high (24 mM) glucose concentrations, and also decreased glucagon secretion from G9 cells and pancreatic islets at 1 mM, whereas a stimulation of glucagon secretion was observed at 6 mM glucose. Our results suggest that resistin can modulate the secretion of insulin and glucagon from clonal β or α cells, and from pancreatic islets.     

Inoperable sinus venosus atrial septal defect in a young woman with severe pulmonary hypertension--a case report

Atrioventricular septal defect accounts for approximately 3% of all congenital cardiovascular malformations. We describe a case of a 34-year-old woman with inoperable sinus venosus atrial septal defect with severe pulmonary hypertension and symptoms of the Eisenmenger syndrome. Electrocardiography, chest radiography, transthoracic and transoesophageal echocardiography with and without contrast were performed and provided valuable information about haemodynamic consequences of this malformation.     

Characterization of the heme synthesis enzyme coproporphyrinogen oxidase (CPO) in zebrafish erythrogenesis

Hemoglobin consists of heme and globin proteins and is essential for oxygen transport in all vertebrates. Although biochemical features of heme synthesis enzymes have been well characterized, the function of these enzymes in early embryogenesis is not fully understood. We found that the sixth heme synthesis enzyme, coproporphyrinogen oxidase (CPO), is predominantly expressed in the intermediate cell mass (ICM) that is a major site of zebrafish primitive hematopoiesis. Knockdown of zebrafish CPO using anti-sense morpholinos (CPO-MO) leads to a significant suppression of hemoglobin production without apparent reduction of blood cells. Injection of human CPO RNA, but not a mutant CPO RNA that is similar to a mutant responsible for a hereditary coproporphyria (HCP), restores hemoglobin production in the CPO-MO-injected embryos. Furthermore, expression of CPO in the ICM is severely suppressed in both vlad tepes/gata1 mutants and in biklf-MO-injected embryos. In contrast, over-expression of biklf and gata1 significantly induces ectopic CPO expression. The function of CPO in heme biosynthesis is apparently conserved between zebrafish and human, suggesting that CPO-MO-injected zebrafish embryos might be a useful in vivo assay system to measure the biological activity of human CPO mutations.     

Primary pituitary lymphoma

Primary CNS lymphoma (PCNSL) is now thought to constitute 3% of all intracranial neoplasms. PCNSL occurrence in the sella turcica region is an extremely rare finding. We present a 37-year-old male with primary pituitary lymphoma treated in our department. The patient, who had had no previous illnesses, was admitted to the hospital because of bilateral blurred vision. Findings on physical examination were normal except for temporal parts of field of vision deficit. No abnormalities were found in his bilateral ocular movement, facial sensory function or motor function. His blood count and biochemical profile were normal. Basic hormonal studies revealed no symptoms of panhypopituitarism. MRI demonstrated a large intrasellar mass with supra- and parasellar extension. MRS revealed decrease in NAA/tCr proportion and increase in Cho/NAA and Cho/tCr proportions. Endoscopic surgery was performed using the transsphenoidal approach. Histopathological examination demonstrated a large B-cell lymphoma. The patient received 6 cycles of CHOP chemotherapy. He was also irradiated with 6 MV photons to the whole brain to a total dose of 40 Gy and then there was a boost to the tumour to a total dose of 50 Gy. Next he was reoperated on with the fronto-temporo-sphenoidal craniotomy approach and subtotal resection of the tumour was performed. After the treatment the visual disturbances significantly decreased. Control MRI revealed a stable remnant of the tumour. Nowadays the patient has 52 months' follow-up and he has only a stable, slight visual field deficit on the upper temporal side of the right eye.