The Genotoxic and Cytotoxic Effects of CT Scan on Buccal Epithelial Cells.

BACKGROUND: Diagnostic radiation is reported to cause significant damage in buccal cells, while the same effects after natural cell turn over cycle were not checked for in previous studies. The buccal cells were studied in patients exposed to computed tomography (CT) scans for evaluating the cells with micronuclei and cytotoxic changes, namely, pyknotic cells, karyorrhectic cells and karyolytic cells. The pre-exposure counts were compared with postexposure counts on 10 and 20 days corresponding to first and second cell turnover cycles. AIM: The aim of this study is to estimate the counts of micronucleus and cytotoxic changes in buccal cells post-exposure to CT scans and report on variance of the same with first and second buccal cell turnover cycles. MATERIALS AND METHODS: This is an observational study, wherein the buccal smears of patients undergoing CT scans were made before and after CT scan exposures as needed. Papanicolaou (PAP) staining and analysis were performed as per standard criteria for micronuclear and cytotoxic changes, respectively. Statistical test used was paired t-tests. RESULTS: The micronuclear counts revealed 0.4% positive cells before exposure and 1.4% positive cells post 10 days and 20 days of exposure were significant (P < 0.005). The cytotoxic changes showed around 2.5% positive cells before and 5.7% positive cells 10 days after CT exposure (P < 0.005). The cytotoxic cell values from baseline to 20th day were not significant (P < 0.25). CONCLUSION: CT scans have caused genotoxic effects notable after two cell turnover cycles but the cytotoxic changes have significantly decreased naturally after 2nd cell turnover as per our study.

Simultaneous spectrophotometric determination of losartan potassium, amlodipine besilate and hydrochlorothiazide in pharmaceuticals by chemometric methods.

In the present work, four different spectrophotometric methods for simultaneous estimation of losartan potassium, amlodipine besilate and hydrochlorothiazide in raw materials and in formulations are described. Overlapped data was quantitatively resolved by using chemometric methods, classical least squares (CLS), multiple linear regression (MLR), principal component regression (PCR) and partial least squares (PLS). Calibrations were constructed using the absorption data matrix corresponding to the concentration data matrix, with measurements in the range of 230.5-350.4 nm (Δλ = 0.1 nm) in their zero order spectra. The linearity range was found to be 8-40, 1-5 and 3-15 µg mL-1 for losartan potassium, amlodipine besilate and hydrochlorothiazide, respectively. The validity of the proposed methods was successfully assessed for analyses of drugs in the various prepared physical mixtures and in tablet formulations.

Serum and cerebrospinal fluid cystatin C levels in vascular and Alzheimer's dementia.

INTRODUCTION: Cystatin C, a cysteine protease inhibitor, has been implicated in the neurodegenerative and repair processes of the nervous system, and the deposition of the same protein together with beta amyloid peptide was found as cerebral amyloid angiopathy (CAA) in different types of dementias. OBJECTIVE AND METHODS: Because of the differential diagnostic importance, serum and cerebrospinal fluid (CSF) cystatin C levels of 24 late onset Alzheimer's demented (AD) and 16 ischemic type of vascular demented (VD) probands were compared with 17 aged control (AC) persons. RESULTS: The serum and CSF cystatin levels were found in the normal range in all groups. The ischemic VD probands had the tendency to have higher cystatin C levels than the AD. No correlation has been found with the severity and duration of dementia and with the other measured parameters. CONCLUSION: These results indicate that lower than normal CSF cystatin C level is not a diagnostic marker in ischemic VD and CAA related to AD.

Hemispheric control of motor function: a whole brain echo planar fMRI study.

The aim of this study was to explore whether recruitment of the ipsilateral motor cortex during non-dominant motor movement reflects left hemispheric control of motor function or simply the greater complexity or unfamiliarity of the motor task. BOLD fMRI was performed in normal right-handers during two motor tasks: (1) sequential finger movements (SM task) with the right or left hand; and (2) random finger movements (RM task) with the right hand. In all subjects, activation was predominantly in the contralateral motor areas (primary sensorimotor, lateral premotor, parietal and supplementary motor regions) and ipsilateral cerebellum. While the ipsilateral motor areas were also activated, single subject analysis revealed these areas to be more extensive and to be seen in more subjects during the non-dominant hand SM task and dominant hand RM task than during the more familiar dominant hand SM task. Similarly, group analysis also revealed ipsilateral activation in the primary sensorimotor and lateral premotor areas, but only during the non-dominant SM task and the dominant hand RM task. Non-dominant hand movements, perhaps because they are less 'automatic', appear to require more cortical activity similar to complex tasks with the dominant hand, and result in greater recruitment of ipsilateral cortical motor areas and striatum. The study also illustrates how potentially meaningful subtleties seen on individual maps may be obscured with group averaging approaches.

Abnormal functional lateralization of the sensorimotor cortex in patients with schizophrenia.

Previous neuroimaging studies have suggested that patients with schizophrenia fail to recruit appropriate focal patterns of cortical responses to cognitive tasks. We investigated whether patients with schizophrenia show a normal focal response to a simple motor task. Seven strongly right-handed patients with schizophrenia and seven strongly right-handed normal subjects performed motor tasks of increasing complexity. Patients were unable to recruit as focal a response even to a simple, automatic sequential finger movement task. They showed greater ipsilateral activation in the primary sensorimotor and lateral premotor regions and had a significantly lower laterality quotient than normal subjects. These phenomena increased with the complexity of the task. These results demonstrate a functional disturbance in the cortical motor circuitry of patients with schizophrenia.

Analysis of interpolation effects in the reslicing of functional MR images.

PURPOSE: Typically, the final step in volume registration is the reslicing of the volume of interest. The purpose of this work is to examine the effects of this reslicing on functional MRI (fMRI) data using different interpolation methods. METHOD: Functional whole-brain echo planar imaging (EPI) volumes were resliced using six different interpolation methods: trilinear, tricubic splines, and a 3D sinc function using a rectangular and a Hanning window, both with half-window lengths of 3 and 4 voxels. RESULTS: Interpolation by tricubic spline and 3D sinc using a Hanning window had comparable errors, although tricubic spline interpolation was computationally the fastest. Interpolation by trilinear and 3D sinc using a rectangular window had relatively large errors, although the speed of trilinear makes it desirable for some applications. CONCLUSION: Interpolations using all of the tested methods adversely affected the fMRI data, although these effects differed for each method.

Effect of magnetization transfer on the measurement of cerebral blood flow using steady-state arterial spin tagging approaches: a theoretical investigation.

A simple four-compartment model for magnetization transfer was used to obtain theoretical expressions for the relationship between regional cerebral blood flow and delta M, the change in longitudinal magnetization of brain water spins when arterial water spins are perturbed. The theoretical relationship can be written in two forms, depending on the approach used to normalize delta M. Using the first approach, the calculation of cerebral blood flow requires a knowledge of R1(omega 1, delta omega), the longitudinal relaxation rate observed in the presence of continuous off-resonance RF irradiation. Using the second approach, the calculation of cerebral blood flow requires a knowledge of R1(omega 1, delta omega), where R1(omega 1, delta omega) is given by the product of R1(omega 1, delta omega) and the fractional steady-state longitudinal water magnetization in the presence of off-resonance RF irradiation. If the off-resonance RF irradiation used for arterial tagging does not produce appreciable magnetization transfer effects, R1(omega 1, delta omega) can be approximated by the longitudinal relaxation rate measured in the absence of off-resonance RF irradiation, R1obs. Theoretical expressions obtained by using the four-component model for magnetization transfer are compared with equivalent expressions obtained by using two-compartment models.

fMRI applications in schizophrenia research.

fMRI has unique potential in the study of psychiatric patients, particularly in characterizing individual variations and changes over time. We have performed four studies of patients with schizophrenia, using three different fMRI acquisition protocols: (1) 3-D echo-shifted FLASH, a multishot volumetric approach; (2) 3-D PRESTO, a hybid of multishot and echo-planar imaging (EPI) methods that also acquires true volumetric data; and (3) a whole-brain isotropic, multislice EPI technique. Patients were studied during sensorimotor activation and during a novel "N back" working memory paradigm. In general, patients show normal sensorimotor activation responses, although motor cortical activation tends to be less completely lateralized. Prefrontal activation during working memory tends to be reduced in patients with schizophrenia even when performance is normal. A major potential confound in studying this patient population with fMRI is the effect of motion. We propose several methodological standards to address this problem, including comparisons of motion corrections parameters, voxel variances, and the use of an "internal activation standard."

Whole-brain functional mapping with isotropic MR imaging.

PURPOSE: To assess the reliability and sensitivity of gradient-echo, isotropic multisection echo-planar magnetic resonance (MR) imaging for within-subject whole-brain mapping. MATERIALS AND METHODS: Eight right-handed healthy volunteers underwent gradient-echo, echo-planar MR imaging while they performed a motor task on three occasions over 2-3 months. Ninety-six whole-brain volumes were acquired in 8 minutes 48 seconds. A rigorous statistical threshold for determining activation was set at P < .05 and was Bonferroni corrected for approximately 15,000 cortical voxels. RESULTS: In all subjects, reproducible activation was demonstrated in multiple cortical areas and in the cerebellum specific to the motor system. Of the activated voxels, 75%-78% were confined to the motor areas during all sessions. No statistically significant difference was found in the proportion of activated voxels in any motor region (relative to the total number of activated voxels in the whole brain) across the three sessions. The centers of mass of the activated areas were within 2.5 resolution elements of the image across the three sessions. CONCLUSION: Isotropic multisection echo-planar MR imaging, has the potential for noninvasive, reliable within-subject mapping of whole-brain functional anatomy.

Fast 3D functional magnetic resonance imaging at 1.5 T with spiral acquisition.

A new method to perform rapid 3D fMRI in human brain is introduced and evaluated in normal subjects, on a standard clinical scanner at 1.5 Tesla. The method combines a highly stable gradient echo technique with a spiral scan method, to detect brain activation related changes in blood oxygenation with high sensitivity. A motor activation paradigm with a duration of less than 5 min, performed on 10 subjects, consistently showed significant changes in signal intensity in the area of the motor cortex. In all subjects, these changes survived high statistical thresholds.

[Endoscopic surgery in the management of carpal tunnel syndrome]. / A carpal tunnel-szindróma endoszkópos mütéti megoldása.

With the spreading of the "minimal invasive surgery" the interest was attracted in the last years in hand surgery too by the endoscopic technique. Authors describe the closed operative treatment according to Chow of the carpal tunnel syndrome. The instruments are presented and the single steps of the method was first used in detail. After exercises on cadavera the method was first used in clinical praxis by them in this country. On the basis of early experiences and the literature, the indication, the possible complications, the advantages and disadvantages of the method are analysed. According their opinion, with sufficient practice and the careful choice of indication, the endoscopic liberation of the carpal tunnel promises to be a remarkable therapeutic possibility.

[Immunohistochemical and immunologic changes in aponeurosis in Dupuytren's disease]. / Immunhisztokémiai és immunológiai változások Dupuytren-kóros aponeurosisban.

Authors examined the aponeurosis of 23 patients with Dupuytren's contracture and of 5, formerly healthy persons, who died in consequence of accidents. It was found that the IgA and IgM content of the palmar aponeurosis is significantly elevated in Dupuytren's disease. The distribution of the immunglobulin containing cells and the fibronection localisation of the aponeurosis was also examined. On the basis of their examinations they think that the autoimmun mechanism may have a role in the development of Dupuytren's disease.

Immunopathological study on palmar aponeurosis in Dupuytren's disease.

The authors examined the immunological and immunohistochemical alterations of palmar aponeurosis in Dupuytren's contracture. In the IgG-content no difference were found between the intact and diseased aponeurosis. The mean of IgA content was 2 fold, the IgM content 3 fold higher in Dupuytren's aponeurosis than in normal ones. The immunoglobulin containing cells localised around the Dupuytren's nodules and in fibrotic, but not nodular parts of aponeurosis. Extracellular immunoglobulin deposits were not found.