Volumetric evaluation of hemicerebellar changes in migraine patients without aura

Brain balance changes have been recognised in migraine, but cerebellar function between or during attacks has been assessed only in a few studies. Previous studies have indicated that migraine affects cerebellar function. In the present study we aimed to evaluate the hemicerebellar volume changes of patients with migraine without aura (MWoA). Volumetric changes of cerebellar hemispheres were evaluated in terms of asymmetry using stereological methods on magnetic resonance images (MRI) retrospectively. Nineteen patients with MWoA and 18 age- and gender-matched control subjects were included in the study. MRIs were analysed by using the point-counting approach of stereological methods by Cavalier’s principle. There was no statistically significant cerebellar atrophy or hemicerebellar asymmetry between the MWoA and control subjects. There was no cerebellar atrophy or asymmetry between the MWoA and age-matched control group. The stereological evaluation of cerebellar asymmetry and atrophy in humans is important for both clinicians and anatomists. The technique is simple, inexpensive, and reliable. (Folia Morphol 2011; 70, 4: 235–239

Comparison of different matching methods in observational studies and sensitivity analysis: The relation between depression and STAI-2 scores

In researches where two or more groups are desired to be compared, observational and randomized experiments are very frequently used. As the subjects are randomly assigned to the groups in randomized experiments, balance is provided in observed/unobserved covariates of subjects in different groups. As the subjects cannot be randomly distributed into groups in observational studies, balance of observed/unobserved covariates between groups is not provided. This situation causes a biased estimate of the treatment effect. In this research, it is focused on different matching methods in observational studies and elimination of observed covariate effects confounding in the group effect, and these methods are examined comparatively. For this purpose, the effect of depression in 300 migraine patients, obtained from an observational study, on State continuous anxiety scale scores is taken and compared with the five different matching methods. Sensitivity of results is examined and it is researched whether the effect of treatment contains any bias. When results are examined, it is seen that matching methods produce similar results due to the overlap of propensity distribution in groups, high and balanced number of subjects in groups and covariates being not so many in number. The effects of unobserved covariates do not change the effect of treatment significantly. In conclusion, it is seen that, in the estimation of group effect in observational studies, it is possible to eliminate the effects of observed covariates using matching methods and matching quality of matching methods based on the propensity score is high. © 2007 Elsevier Ltd. All rights reserved

Grain yield response and N-fertiliser recovery of maize under deficit irrigation

Grain yield response and nitrogen (N) fertiliser recovery of maize (Zea mays L. cv. Sele) were assessed as influenced by deficit irrigation that was imposed either using conventional deficit irrigation (DI) or partial root drying (PRD) practice. The two deficit irrigation treatments were compared with FULL irrigation, the control treatment where rooting zone soil-water content was increased to field capacity at each irrigation, whereas 50% deficit irrigation was applied to the deficit treatments, DI50 and PRD50. Under the PRD practice, one-half of the rooting zone was wetted while the other half was maintained partially dry, thereby reduced amount of irrigation water was needed. The wetted and partially dry sides were interchanged in the subsequent irrigations. Under conventional DI, plants again received reduced amounts of water but the water was uniformly applied to both sides of the plant row. A popular hybrid maize-cultivar Sele was planted, following harvest of wheat. The study was conducted for two consecutive years in 2001 and 2002. A composite fertiliser of N, P and K, all at 80 kg ha-1 was applied before planting. At the ninth leaf (V9) stage, a second application of N-fertiliser at 170 kg N ha -1 rate was made. Difference method (plots with or without N-fertiliser application) was used for estimation of plant N-uptake efficiency. Contrary to earlier reports, the PRD treatment did not result in any yield benefit compared to the conventional deficit irrigation. The range of grain yield reduction under deficit irrigation treatments, DI50 and PRD50, was 10-25% and significant (P ? 0.01), compared to FULL irrigation practice. Measurements, including xylem sap abscisic acid concentration, photosynthetic rate and stomatal conductance under DI50 and PRD50 treatments followed a nearly identical trend. The PRD irrigation practice had the highest N-fertiliser recovery among the irrigation treatments, with minimal mineral N residue left after maize harvest. The recoveries under FULL and DI50 treatments were 17 and 24% less, respectively, than the PRD treatment. The PRD irrigation practice was not only as effective as conventional deficit irrigation (DI) in saving water, but it should also be regarded as an environmentally friendly irrigation practice due to its association with low mineral N residue left in the soil. © 2004 Elsevier B.V. All rights reserved.European Commission: ICA3-CT-1999-00008The authors gratefully acknowledge that this work was funded by European Union, through INCO-MED RTD project (ICA3-CT-1999-00008). Thanks are due to the Staff of Department of Biological Sciences, University of Lancaster, UK, for their help in ABA analysis, and to Dr. J.S. Schepers in Agronomy Department, University of Nebraska, USA, for editing the paper and valuable comments

Evaluation of cerebellar asymmetry in Alzheimer's disease: A stereological study

PubMed: 19602887Objectives: Alzheimer's disease (AD) is the most common cause of dementia and, as previous studies have indicated, degenerative changes in the cerebellum occur in AD. It is well known that the cerebellum does not have a symmetric morphology and some pathological disorders, such as schizophrenia, epilepsy, autism and alcoholism, can cause asymmetrical changes in the cerebellum. In this study, we aimed to evaluate whether or not patients with AD show cerebellar asymmetry. We also intended to depict the probable volumetric asymmetry by using a stereological technique. Materials and Methods: The study evaluated the volu- metric measurements of each cerebellar hemisphere by applying a stereological method to MR images. This age- and gender-matched study was composed of 15 patients with probable AD and 14 healthy subjects (controls). MR images were analyzed by using the point-counting approach, holding to Cavalieri's principle. Results: Although there was significant cerebellar atrophy in AD patients, the study showed no statistically significant cerebellar asymmetry according to age and gender, both in the study and control groups (p > 0.05). Conclusions: There was no difference in cerebellar asymmetry associated with age and gender between the AD patients and control subjects. The stereological evaluation of cerebellar asymmetry correlating with gender is of importance to both clinicians and anatomists. The technique is simple, inexpensive, reliable and unbiased. Copyright © 2009 S. Karger AG

Vertigolu olgularda cerebellar asimetrinin değerlendirilmesi

PubMed: 19263348Aim: We aimed to evaluate the relevant methods of stereology to estimate cerebellar asymmetry according to gender in both adult right-handed vertigo cases and healthy cases. Material and Methods: The study included 14 adult control subjects and 18 patients with vertigo. The volumes of the cerebellar hemispheres were determined on MRI using the point-counting approach of stereological methods. Results: The mean (±SD) of the right cerebellar hemispheres in the patients with vertigo were 52.49±5.42 cm3 in males, 50.11±4.02 cm3 in females. The mean (±SD) of the left cerebellar hemispheres in the patients with vertigo were 53.11±3.70 cm3 in males and 49.73±4.69 cm3 in females. There was no significant quantitative evidence detected in terms of cerebellar asymmetry between sagittal plane estimates in the cases with vertigo in both genders (p>0.05). There were no statistically significant differences by genders between vertigo and control subjects (p>0.05). There was statistical significance only between right and left hemispheres in male control subjects (p=0.039) Conclusion: There was no cerebellar asymmetry between control and vertigo cases by gender. The stereological evaluation of cerebellar asymmetry or atrophy in humans in correlation with gender is of importance both for clinicians and anatomists. The technique is simple, reliable, inexpensive and unbiased