The hippocampus develops rapidly during the late fetal and early postnatal periods. Fetal/neonatal iron deficiency anemia (IDA) alters the genomic expression, neurometabolism and electrophysiology of the hippocampus during the period of IDA and, strikingly, in adulthood despite neonatal iron treatment. To determine how early IDA affects the structural development of the apical dendrite arbor in hippocampal area CA1 in the offspring, pregnant rat dams were given an iron-deficient (ID) diet between gestational day 2 and postnatal day (P) 7 followed by rescue with an iron-sufficient (IS) diet. Apical dendrite morphology in hippocampus area CA1 was assessed at P15, P30 and P70 by Scholl analysis of Golgi-Cox-stained neurons. Messenger RNA levels of nine cytoplasmic and transmembrane proteins that are critical for dendrite growth were analyzed at P7, P15, P30 and P65 by quantitative real-time polymerase chain reaction. The ID group had reduced transcript levels of proteins that modify actin and tubulin dynamics [e.g. cofilin-1 (Cfl-1), profilin-1 (Pfn-1), and profilin-2 (Pfn-2)] at P7, followed at P15 by a proximal shift in peak branching, thinner third-generation dendritic branches and smaller-diameter spine heads. At P30, iron treatment since P7 resulted in recovery of all transcripts and structural components except for a continued proximal shift in peak branching. Nevertheless, at P65–P70, the formerly ID group showed a 32% reduction in 9 mRNA transcripts, including Cfl-1 and Pfn-1 and Pfn-2, accompanied by 25% fewer branches, that were also proximally shifted. These alterations may be due to early-life programming of genes important for structural plasticity during adulthood and may contribute to the abnormal long-term electrophysiology and recognition memory behavior that follows early iron deficiency.
An ALSCAL multidimensional scaling analysis in Euclidean space revealed that three orthogonal perceptual dimensions can account for the judged tactile dissimilarities of raised-dot patterns. Through magnitude estimates of various perceptual attributes, it was determined that the three dimensions consist of blur, roughness, and clarity. The only effect that selective adaptation of the Pacinian (P) channel had was to change the perceptual clarity of the raised dots against their background. Adaptation of the P channel with a 20 dB SL 250 Hz stimulus enhanced clarity. As indicated by magnitude estimates, adaptation of the P channel by the 250 Hz stimulus had no effect on the perceived roughness of the dot pattern but did cause the individual dots of the textured pattern to feel smoother. When the observer was required to estimate magnitude "overall roughness" defined as a combination of dot-pattern roughness and individual-dot roughness, adaptation of the P channel affected perceived roughness by reducing it. Taken as a whole, the results are consistent with the hypothesis that the NP channels and the P channel jointly influence the perception of textured surfaces.
Listeners with normal hearing (NH) and sensorineural hearing loss (SNHL) were asked to compare pairs of noise stimuli and choose the louder noise in each pair. Each noise was made up of 15, two-ERB (equivalent rectangular bandwidth) wide frequency bands that varied independently over a 12-dB range from one presentation to the next. Mean levels of the bands followed the long-term average speech spectrum (LTASS) or were set to 43, 51, or 59 dB sound pressure level (SPL). The relative contribution of each band to the total loudness of the noise was determined by computing the correlation between the difference in levels for a given band on every trial and the listener's decision on that trial. Weights for SNHL listeners were governed by audibility and the spectrum of the noise stimuli, with bands near the spectral peak of the LTASS noise receiving greatest weight. NH listeners assigned greater weight to the lowest and highest bands, an effect that increased with overall level, but did not assign greater weight to bands near the LTASS peak. Additional loudness-matching and paired-comparison studies using stimuli missing one of the 15 bands showed a significant contribution by the highest band, but properties other than loudness may have contributed to the decisions.
Background: Patients with peripheral artery disease (PAD) who experience intermittent claudication report a range of symptoms. Patients with symptoms other than classically described intermittent claudication may be at the highest risk for functional decline and mobility loss. Therefore, technologies allowing for characterization of PAD severity are desirable. Near-infrared spectroscopy (NIRS) allows for measurements of muscle heme oxygen saturation (StO 2 ) during exercise. We hypothesized lower extremities affected by PAD would exhibit distinct NIRS profiles as measured by a lowcost, wireless NIRS device and that NIRS during exercise predicts walking limitation. Methods:We recruited 40 patients with PAD and 10 control participants. All patients with PAD completed a computed tomographic angiography, 6-minute walk test, and a standardized treadmill test. Controls completed a 540-second treadmill test for comparison. StO 2 measurements were continuously taken from the gastrocnemius during exercise.Variables were analyzed by Fischer's exact, c 2 , Wilcoxon rank-sum, and Kruskal-Wallis tests as appropriate. Correlations were assessed by partial Spearman correlation coefficients adjusted for occlusive disease pattern.Results: Patients with PAD experienced claudication onset at a median of 108 seconds with a median peak walking time of 288 seconds. The baseline StO 2 was similar between PAD and control. The StO 2 of PAD and control participants dropped below baseline at a median of 1 and 104 seconds of exercise, respectively (P < .0001). Patients with PAD reached minimum StO 2 earlier than control participants (119 seconds vs 522 seconds, respectively; P < .001) and experienced a greater change in StO 2 at 1 minute of exercise (À73.2% vs 8.3%; P < .0001) and a greater decrease at minimum exercise StO 2 (À83.4% vs À16.1%; P < .0001). For patients with PAD, peak walking time, and 6-minute walking distance correlated with percent change in StO 2 at 1 minute of exercise (r ¼ À0.76 and -0.67, respectively; P < .001) and time to minimum StO 2 (r ¼ 0.79 and 0.70, respectively; P < .0001). Conclusions:In this initial evaluation of a novel, low-cost NIRS device, lower extremities affected by PAD exhibited characteristic changes in calf muscle StO 2 , which differentiated them from healthy controls and were strongly correlated with walking impairment. These findings confirm and expand on previous work demonstrating the potential clinical value of NIRS devices and the need for further research investigating the ability of low-cost NIRS technology to evaluate, diagnose, and monitor treatment response in PAD. (J Vasc Surg 2020;71:946-57.)
This report describes a case of postoperative bilateral brachial plexopathy following laparoscopic bariatric surgery. The patient, a 39-year-old morbidly obese man, developed motor and sensory deficit, loss of reflexes, and pain in both arms postoperatively. Slow, but complete recovery occurred over nine months. We postulate that the head-up position in obese patients, without specific arm support, is a risk factor for brachial plexus injury.
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