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Positron Emission Tomography and Neuropsychological Studies in Dementia
Published in Robert E. Becker, Ezio Giacobini, Alzheimer Disease, 2020
Randolph W. Parks, Robert E. Becker, Kathryn L. Dodrill, Bettina A. Bennett, David J. Crockett, Trevor A. Hurwitz, Patrick L. McGeer, Edith G. McGeer
Local cerebral metabolic rates for glucose in 32 regions of interest were reported upon my McGeer et al. (in press) on patients with clinically diagnosed AD and 20 neurological normal controls. This study also reported serial investigations on 13 AD patients. At the same time, extensive neuropsychological testing was done on all AD patients. In almost all cortical regions, there was a significant decline in local cerebral metabolic rates for glucose with age in the control subjects. There were the expected cortical metabolic deficits seen in AD. Moreover, the serial study showed a general increase in such deficits over time in 12 of the 13 cases. The region showing the greatest decline with time in the serial study is the same as showing the most severe deficiencies in cross sectional studies. Results on individual neuropsychological tests tend to correlate with metabolic rates in multiple rather than single, cortical regions, suggesting intact neural networks are required for good performance. The correlation with cortical metabolic activity indicated that the higher the metabolic rates, the better the performance. In addition, a better balance in activity between the right and left hemispheres as reflected by left right asymmetry index was also associated with better performance on the neuropsychological test.
Biological Predictions from the Conduction Delay Hypothesis of Cerebral Lateralization
Published in Robert Miller, Axonal Conduction Time and Human Cerebral Laterality, 2019
Definition of the planum is not uniform between studies, since one or more of the transverse temporal gyri lying in the anterior part of the superior temporal surface may or may not be included. Campain and Minckler (1976) found that neither the number of transverse temporal gyri, nor their surface area differed from left to right. Chi et al. (1977a), who studied 207 foetal brains, from 10-44 weeks of gestation, found that 54% of brains had more, and larger, transverse temporal gyri on the right as well as a longer left temporal planum (see also Chi et al., 1977b). Witelson and Pallie (1976) measured areas of left and right planum defined in a “biased” way, and in an “unbiased” manner (the latter definition not making assumptions about the number of gyri on superior surface of temporal lobe anterior to the planum). The left/right asymmetry was detectable and statistically significant using either method, but was less using the unbiased method. (The left planum on average had an area 1.6 times that of the right [p < 0.05] using the unbiased method and 2.4 times that of the right using the biased method [p < 0.005]).
Approaches to Studying Polycystic Kidney Disease in Zebrafish
Published in Jinghua Hu, Yong Yu, Polycystic Kidney Disease, 2019
ProcedureArray embryos into 12-well plates with 25 embryos per well. 12-well plates are chosen here as the embryos are from heterozygous cross and only 25% embryos are expected as homozygous mutants. For treating wildtype embryos with chemicals, use 96-well plate and 3 embryos per well instead.At 50% epiboly stage, chemicals were added at a starting concentration of 10 × IC50 or 10 μM with 1% DMSO. Use embryos in 1% DMSO as a control at each time.Analyze phenotypes, including left-right asymmetry; body curvature; and cystic kidney at 30 hpf, 2, 3, and 5 dpf, respectively. Left-right asymmetry was determined by examining the heart position in the embryos at 30 hpf.Take images.(Optional) Titrate: If the chemical causes severe abnormality or lethality in the embryo, decrease the concentration by 5–10 fold. On the contrary, if the chemical barely affects the embryonic development, increase the concentration by 5–10 fold.
Adduction-Abduction Asymmetry in Saccades During Video-Oculographic Monocular Recording: A Word of Caution
Published in Neuro-Ophthalmology, 2019
Koji Takahashi, Osamu Tanaka, Yosuke Kudo, Eriko Sugawara, Ken Johkura
During the measurement of right eye movements, there were significant directional differences only in the saccade parameters. The saccade latency was significantly shorter, and the saccade velocity and accuracy were significantly larger in the left (adduction) direction than in the right (abduction) direction. Additionally, the smooth pursuit gain did not differ between both directions. Because the left–right asymmetry may be due to characteristics of measuring with right eye, we additionally measured left eye saccades and smooth pursuits in 10 healthy subjects (3 men and 7 women, aged 23–55 years [mean ± SD = 38.3 ± 12.1 years]), and confirmed that saccade velocity and accuracy were larger in the right (adduction) direction than in the left (abduction) direction (Supplement 1). Furthermore, in this study, the laser pointer (visual target) generator was placed just above the forehead (midline). It was slightly shifted from the centre of the measured eye, and thus, might have affected the measurement results. Therefore, we additionally measured left eye saccades and smooth pursuits with the position of the laser pointer (visual target) generator shifted from just above the forehead towards the lateral (left) direction in a healthy subject (23-year-old woman), and confirmed the adduction dominancy of saccades (Supplement 2).
Distribution of age and apnea-hypopnea index in diagnostic sleep tests in West Texas
Published in Baylor University Medical Center Proceedings, 2022
Jonathan Kopel, Silvia Jakubski, Mhd Hasan Al-Mekdash, Gilbert Berdine
This left-right asymmetry of appearance can be quantitated as skew, which is the third power moment of the distribution. The skewness measurement of the age distribution was −0.144. Another type of deviation from the normal distribution is kurtosis.11 Kurtosis is the fourth power moment of the distribution and measures whether subjects are more common near the mean or more common in the tails. Curves with positive excess kurtosis have higher peaks and thinner tails, while curves with negative excess kurtosis have shorter peaks and thicker tails. The excess kurtosis measurement of the study age distribution was −0.413.
Inhalation dosimetry of nasally inhaled respiratory aerosols in the human respiratory tract with locally remodeled conducting lungs
Published in Inhalation Toxicology, 2021
Xiuhua April Si, Mohamed Talaat, Wei-Chung Su, Jinxiang Xi
In comparison to the left-right asymmetry in flow partition in Figure 4, the deposition asymmetry between the left and right lungs is even more pronounced (Figure 4 vs. Figure 10). This DF asymmetry is especially apparent in M4 with the most severe constrictions and is even more significant for smaller particle size (i.e. 1 nm vs. 100 nm) at a lower inhalation flow rate (15 L/min vs. 45 L/min, Figure 10). For instance, the left–right flow partition in M4 at 15 L/min is around 0.32:0.68 (Figure 4), while the corresponding left-right DF distribution is 0.21:0.79 for 1 nm (calculated from 2.6%:9.7%, Figure 10).