Application of Intravoxel Incoherent Motion (IVIM) Model for Differentiation Between Metastatic and Non-Metastatic Head and Neck Lymph Nodes.

BACKGROUND: Application of intravoxel incoherent motion (IVIM) model parameters, including: true diffusion (D), pseudodiffusion (D*), and perfusion fraction (Fp), for differentiation between metastatic and non-metastatic head and neck lymph nodes. MATERIAL/METHODS: Diffusion-weighted images/apparent diffusion coefficient (DWI/ADC) images of 86 lymph nodes from 31 cancer patients were analyzed. DWI images were obtained with a 1.5T MRI scanner (Magnetom Avanto); b=0,50, 150, 300, 500, 750, 1000, 1200 s/mm2. RESULTS: In the study group, there were 32 (37%) and 54 (67%) metastatic and non-metastatic lymph nodes, respectively. The mean values of D, D*, and Fp did not differ significantly between metastatic and non-metastatic lymph nodes. CONCLUSIONS: IVIM parameters are not useful for differentiation between metastatic and non-metastatic head and neck lymph nodes.

Anaplastic transformation of low-grade gliomas (WHO II) on magnetic resonance imaging.

INTRODUCTION: Malignant transformation among gliomas WHO II ranges between 35% and 89%. However, according to some reports, all gliomas WHO II undergo such transformation over time. The aim of the study was to analyse MRI parameters indicating anaplastic transformation of gliomas WHO II. MATERIAL AND METHODS: Forty-six consecutive patients were enrolled in the study (20 females and 26 males; range of age 36 ± 9 years) with supratentorial glioma WHO II. Multiparametric MR examination included morphological imaging, perfusion-weighted imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy. Group division depended on the course of disease (ST - stable group, AT - anaplastic transformation group). RESULTS: Subtotal tumour resection was achieved in the whole AT group, whereas in the ST group, total tumour resection was achieved in 10/29 (34%) patients. The size of the residual tumour after surgery was statistically significantly higher in the AT group compared to the ST group (AT: 51.5 cm³ ± 37.7 vs. ST: 29.0 cm³ ± 37.9; p = 0.011). Contrast enhancement in the AT group occurred in 5/11 (45%) of tumours and in none of the patients' areas of contrast enhancement were resected during surgery/biopsy. However, the initial MR showed contrast enhancement in 10/29 (34%) of patients in the ST group. The areas of contrast enhancement were totally resected in all patients. Compared to the ST group tumours that underwent anaplastic transformation had statistically significantly higher values of mean nrCBV and max nrCBV on the initial MR, the follow-up and final MR examinations. However, statistically significant differences between the groups in ADC values were observed on the follow-up and final MR whereas mean Cho/Cr and mean Cho/NAA were observed as late as on the final MR examination. CONCLUSIONS: Multiparametric MR examination allows the detection of LGGs with high probability of rapid anaplastic transformation and the detection of transformation prior to the occurrence of contrast enhancement. The value of nrCBV is the most useful in the diagnosis of anaplastic transformation. The resection of contrast enhancement area of the tumour significantly increases time to anaplastic transformation of LGGs.

Stem cells as therapy for cardiac disease - a review.

Acute myocardial infarction (AMI) is one of the most significant causes of morbidity and mortality worldwide. Stem cells represent an enormous chance to rebuild damaged heart tissue. Correct definition of the cardiac progenitors is necessary to understand heart development, and would pave the way for the use of cardiac progenitors in the treatment of heart disease. Identifying, purifying and differentiating native cardiac progenitor cells are indispensable if we are to overcome congenital and adult cardiac diseases. To understand their functions, physiology and action, cells are tested in animal models, and then in clinical trials. But because clinical trials yield variable results, questions about proper cardiac stem cells remain unanswered. Transplanted stem cells release soluble factors, acting in a paracrine fashion, which contributes to cardiac regeneration. Cytokines and growth factors have cytoprotective and neovascularizing functions, and may activate resident cardiac stem cells. Understanding all these mechanisms is crucial to overcoming heart diseases.

Fibre integrity and diffusivity of the pyramidal tract and motor cortex within and adjacent to brain tumour in patients with or without neurological deficits.

BACKGROUND: Assessment of the relationship between preoperative neurological deficits and diffusion tensor imaging (DTI) parameters in patients with brain tumour within/adjacent to pyramidal tract and motor cortex. Evaluation of the difference in fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in patients with low and high grade gliomas. MATERIAL AND METHODS: 20 patients with supratentorial brain tumours were divided into two groups: I with preoperative neurological deficits and II without preoperative neurological deficits. 8/20 tumours were classified as low grade gliomas, 10/20 as high grade gliomas and 2/10 as metastases. All MR examinations were performed on a 3T scanner. FA and ADC values were calculated for a precentral gyrus (PCG), a posterior limb of the internal capsule (PLIC) and a pyramidal tract (PT) ipsilateral and contralateral to the tumour side. These values were compared between patients with and without preoperative neurological deficits, with low and high grade gliomas. RESULTS: A statistical analysis revealed significant differences between patients with and without preoperative neurological deficits in PCGs and PTs ipsilateral to the tumour side. Separate analysis conducted in the group with preoperative neurological deficits showed significant statistical differences only in terms of FA values comparing ipsilateral and contralateral tumour side. No statistically significant difference was observed comparing FA and ADC values ipsilateral and contralateral to the tumour side in the group without preoperative neurological deficits and between patients with low and high grade gliomas. CONCLUSIONS: There is a relation between FA and ADC values and preoperative deficits in patients with brain tumour adjacent/within the main white matter tracts. Tumour relation to the white matter tracts is more important than the glioma WHO grade.

[Use of adipose tissue as a source of mesenchymal stem cells]. / Wykorzystanie tkanki tluszczowej jako zródla mezenchymalnych komórek macierzystych.

Enormous expectations are associated with stem cells with regard to cell therapy and tissue engineering. Stem cells have unlimited potential for self-renewal and develop into various cell types. For the mesodermal tissue engineering such a source of cells is the bone marrow stroma. However, isolation of the bone marrow requires general or spinal anesthesia and yields low number of mesodermal stem cells (MSCs) upon processing (1 MSC per 105 adherent stromal cells). An alternative source of autologous stem cells seems to be, apart from bone marrow: periosteum, muscular tissue or synovial membrane and adipose tissue. The adipose tissue is derived from the embryonic mesenchyme, contains a large number of stromal stem cells and is relatively easy to obtain in large quantities. It covers a widespread area of human body, and can be classified as white and brown adipose tissue in terms of location and function. Specimens of the adipose tissue are usually obtained from elective, laparoscopic or liposuction surgeries. Stromal stem cells, isolated from this tissue, exhibit characteristics common to mesodermal tissues, including: adherence to plastic, formation of fibroblastic- like colonies, extensive proliferative capacity, ability to differentiate into several mesodermal lineages (including bone, cartilage, muscle and fat), and expression of several common cell surface antigens. Recent evidence suggest that these cells can also form non-mesodermal tissues--neuron-like cells. The aim of this publication is to describe the application of the adipose tissue as a source of mesenchymal stem cells based on current literature data.

[Natural factors influencing sleep]. / Naturalne czynniki wplywajace na sen.

Sleep is a universal phenomenon of human and animal lives, although the importance of sleep for homeo-stasis is still unknown. Sleep disturbances influence many behavioral and physiologic processes, leading to health complications including death. On the other hand, sleep improvement can beneficially influence the course of healing of many disorders and can be a prognostic of health recovery. The factors influencing sleep have different biological and chemical origins. They are classical hormones, hypothalamic releasing and inhibitory hormones, neuropeptides, peptides and others as cytokines, prostaglandins, oleamid, adenosine, nitric oxide. These factors regulate most physiologic processes and are likely elements integrating sleep with physiology and physiology with sleep in health and disorders.

[Usefulness of FDG-PET for the diagnosis of brain tumors]. / Przydatnosc FDG-PET w diagnostyce guzów mózgu.

Although magnetic resonance imaging (MRI) and X-ray computed tomography (CT) are the two imaging modalities used conventionally for the morphological OUN imaging, there are many cases for positron emission tomography (PET) diagnostic. Basal radiopharmaceutic used in PET is a 18F-2-Fluoro-2-deoxy-D-glucose (18FDG). Use of PET imaging provides in vivo biochemical and physiological data and therefore can provide unique functional information about tumors compared to histological or anatomic neuroradiological methods. PET can provide information regarding tumor grading, delineation of tumors margins, differentiation of recurrent brain tumors from necrosis (golden standard), guidance for stereotactic biopsy, response to therapy and prognosis. New value in brain tumor imaging is combining two essential and complementary imaging modalities PET and multisection CT to create one integrated unit that allows both functional and anatomic imaging in a single study. This allows PET-CT for more accurate tumor localization and variability assessment changes impressions and increases diagnostic confidence. The first PET-CT centre in Poland is localised in Cancer Centre in Bydgoszcz. Scanning is performed on a dedicated Biograph (PET-CT) LSO scanner (SIMENS, Germany), and cyclotron RDS-111 (CTI, USA), FDG production laboratory (NUCLEAR INTERFACE, Germany, COMECER, Italy) and FDG quality control (RAYTES, Germany) are radiopharmaceutical production unit.

Effects of amphetamine on NK-related cytotoxicity in rats differing in locomotor reactivity and social position.

The effect of i.p. administration of 1mg/kg of amphetamine (AMPH) on natural killer cells cytotoxicity (NKCC) and number of large granular lymphocytes (LGL-NK) together with plasma corticosterone (CORT) level and WBC was evaluated in male Wistar rats differing in two behavioral features: locomotor reactivity to novelty (high, HR and low, LR responders) and social position (dominants, D and subordinates, S). In the majority of animals AMPH evoked (30 min after administration) an increase in NKCC and LGL (NK) number accompanied by lymphopenia, neutrocytosis, monocytosis, and an increase in CORT level. Changes in NKCC (LU20) showed substantial individual variability: in HR group approximately 513Delta%, p <0.01 (relative to the control); LR group approximately 56Delta%, p >.05; D group approximately 441Delta%, p >0.001; S group approximately 216Delta%, p >0.05; HR/D group approximately 643Delta%, p <.001; HR/S group approximately 414Delta%, p <.001; LR/D group approximately 191Delta%, p >.05; and LR/S group approximately -19Delta%, p .05. The increase in CORT level, lymphopenia, and neutrocytosis indicated a stress-like reaction to AMPH. No significant correlation between NKCC and CORT level was found. The results obtained indicate that AMPH can evoke an increase in NK-related cytotoxic activity quantitatively related to high behavioral reactivity to novelty and social dominance, however NKCC is not related to the AMPH-induced CORT changes.

Influence of small mechanical head injuries on peripheral blood natural killer cytotoxicity (NKCC) in rats.

Many neurophysiological experiments and some human's brain tissue stimulatory therapies require surgery intervention, which results in small mechanical skull and brain tissue injuries. Additionally, these procedures need some local or short general anaesthesia, which is not neutral for immune system action. Clinical data unambiguously shows that severe head and brain injuries and anaesthesia can suppress immunity. The aim of the present study was to investigate the influence of small mechanical skull and brain tissue injuries, accompanied by electrode fixation for experimental or therapeutic brain tissue stimulation, on peripheral blood natural killer cytotoxicity (NKCC) assessed in a 4h standard cytotoxic test. Additionally, we assessed a number of leukocytes, lymphocytes and large granular lymphocytes (LGL), which are NK cell subset and plasma corticosterone concentration. The results showed that small mechanical skull and meninges injuries or alone-administered Nembutal did not evoke any significant changes as those caused by electrode placement 4.2 mm below the skull surface. Deeper electrode fixation, 6.1; 7.6 and 8.4 mm below the skull surface, significantly increased NKCC (p < 0.05) and LGL number (p < 0.05) on the 3rd day after the electrode placement. Moreover, the results showed that some small brain tissue injuries could transiently influence the number of LGL and NKCC.

Effect on peripheral blood natural killer cytotoxic cell activity in rats after intraperitoneal implantation of double veloured polyester (Dacron) prosthesis.

INTRODUCTION: The aim of this study was to assess the changes affecting natural killer cytotoxic cell (NKCC) activity following intraperitoneal implantation of a double veloured polyester prosthesis in a rat model. MATERIAL/METHODS: Blood samples were taken by cardiac puncture 1 h before (base line) and 14, 28, 100 and 180 days post-implantation. Peripheral blood mononuclear cells were separated from heparinized blood by density centrifugation. A standard, 4 h (51)Cr-release assay against YAC-1 target cells at effector to target ratios of 12:1; 25:1 and 50:1 was performed and the number of total leukocytes, lymphocytes, granulocytes, monocytes, and large granular lymphocytes (LGLs), as well as serum corticosterone levels (radioimmunoassay method) were determined. RESULTS: Comparative analysis of the results obtained from animals with implants, baseline samples, and a control group (laparotomy only) revealed lower NKCC, LGL, leukocyte and lymphocyte counts and elevated plasma corticosterone levels in animals receiving the implant on the 14th day post-implantation. CONCLUSIONS: Our findings indicate that the polyester implant can transiently modulate immune system activities. Since NK cells are important in the control of viral infection and carcinogenesis in humans, it is possible that the stress generated by polyester prostheses can exacerbate the surgical stress and put patients at a higher risk for viral infection and/or metastases.

The effects of lateral hypothalamic lesions on peripheral blood natural killer cell cytotoxicity in rats hyper- and hyporesponsive to novelty.

Individual variability in the central control of the cellular immune responses is the main subject of the study. Previously, it was found that destruction of the lateral hypothalamus (LH) produced long-term depression of the cytotoxicity of NK cells (NKCC) and their number (LGL). In the present experiment we compared changes in the peripheral blood NKCC, LGL number, as well as leukocyte and lymphocyte number, their mitogenic activity and plasma corticosterone level evoked by electrolytic LH lesions in rats which were categorized as either high (HR) and low (LR) responders according to their locomotor response to a new environment. It was found that: (1) before the lesion NKCC (measured by 51Cr release assay) was higher in the HRs than in LRs; (2) LH damage caused a drop in NKCC and LGL number (21st postlesion day) preceded by a transient enhancement (5th postlesion day) significant for HRs only. As a result of a greater decrease in the HRs than LRs the baseline differences between groups disappeared by 21st postlesion day; (3) NKCC and LGL depression was not accompanied by changes in lytic activity of a single NK cell (agarose assay) which indicates that NKCC decrease concerned the population level and was dependent on LGL redistribution and/or recycling rate; (4) on the 21st postlesion day there was a significant leuko- and lymphopenia in the lesioned groups both HRs and LRs; (5) proliferative lymphocyte response to PWM (colorimetric assay) and plasma corticosterone level were not affected either by the motility level or by the lesion. The results emphasize the importance of individual differences in behavioral reactivity for NKCC regulation and a possible involvement of LH in the mechanism which connects high locomotor activity with stimulation of NKCC.