No abstract

Values for the size of the normal pediatric gallbladder are defined and will be helpful in the diagnosis of gallbladder abnormalities.

Objective: To elucidate the frequency, underlying mechanisms, and clinical implications of spontaneous reversal of positional nystagmus (SRPN) in benign paroxysmal positional vertigo (BPPV). Methods: We prospectively recruited 182 patients with posterior canal (PC, n = 119) and horizontal canal (HC) BPPV (n = 63) canalolithiasis. We analyzed the maximal slow phase velocity (maxSPV), duration, and time constant (Tc) of positional nystagmus, and compared the measures between groups with and without SRPN. We also compared the treatment outcome between two groups. Results: The frequency of SRPN in PC-and HC-BPPV was 47 and 68%, respectively. The maxSPVs were greater in BPPV with SRPN than without, larger in HC-BPPV than PC-BPPV (114.3 ± 56.8 vs. 57.1 ± 38.1 • /s, p < 0.001). The reversed nystagmus last longer in HC-BPPV than PC-BPPV. The Tc of positional nystagmus got shorter in PC-BPPV with SRPN (3.7 ± 1.8 s) than without SRPN (4.5 ± 2.0 s, p = 0.034), while it was longer during contralesional head turning in HC-BPPV with SRPN (14.8 ± 7.5 s) than that of ipsilesional side (7.3 ±2.8 s, p < 0.001). The treatment response did not significantly differ between groups with and without SRPN in both PC-and HC-BPPV (p = 0.378 and p = 0.737, respectively). Conclusion: The SRPN is common in both PC-and HC-BPPV canalolithiasis. The intensity of rotational stimuli may be a major determinant for the development of short-term central adaptation which utilizes the velocity-storage system below a certain velocity limit. The presence of SRPN is not related to treatment outcome in BPPV.

No abstract

Neuropeptide Y (NPY) is found throughout the central nervous system where it appears to be involved in the regulation of a wide range of physiological effects. The Mongolian gerbil, a member of the rodent family Muridae, is a diurnal animal and has been widely used in various aspects of biomedical research. This study was conducted to investigate the organization of NPY-immunoreactive (IR) neurons in the gerbil visual cortex using NPY immunocytochemistry. The highest density of NPY-IR neurons was located in layer V (50.58%). The major type of NPY-IR neuron was a multipolar round/oval cell type (44.57%). Double-color immunofluorescence revealed that 89.55% and 89.95% of NPY-IR neurons contained gamma-aminobutyric acid (GABA) or somatostatin, respectively. Several processes of the NPY-IR neurons surrounded GABAergic interneurons. Although 30.81% of the NPY-IR neurons contained calretinin, NPY and calbindin-D28K-IR neurons were co-expressed rarely (3.75%) and NPY did not co-express parvalbumin. Triple-color immunofluorescence with anti-GluR2 or CaMKII antibodies suggested that some non-GABAergic NPY-IR neurons may make excitatory synaptic contacts. This study indicates that NPY-IR neurons have a notable architecture and are unique subpopulations of the interneurons of the gerbil visual cortex, which could provide additional valuable data for elucidating the role of NPY in the visual process in diurnal animals.

Detection of small-sized maritime targets is an important task for a marine surveillance radar. Recently, with the emergence of a marine surveillance radar system that has a narrow azimuth beamwidth and rapidly rotating antennas, the available dwell time for detecting a maritime target is usually very short. This short dwell time considerably degrades the performance of conventional detectors, especially those focusing on small-sized targets. In this paper, we propose an efficient detector for small-sized maritime targets to provide a reliable detection performance, even in short dwell times. The proposed scheme is based on a new joint metric, which results from the product of the magnitude and difference features in the Doppler spectra. We discriminate the target bins from sea clutter bins using a statistical discriminator based on the joint metric, whose probability density function follows the product distribution of standard gamma distributions. Compared to conventional detectors, the proposed scheme can provide a robust performance in terms of the average signal-to-clutter ratio as well as the detection rate, especially in shorter dwell times.

No abstract

Somatostatin (SST) is widely expressed in the brain and plays various, vital roles involved in neuromodulation. The purpose of this study is to characterize the organization of SST neurons in the Mongolian gerbil visual cortex (VC) using immunocytochemistry, quantitative analysis, and confocal microscopy. As a diurnal animal, the Mongolian gerbil provides us with a different perspective to other commonly used nocturnal rodent models. In this study, SST neurons were located in all layers of the VC except in layer I; they were most common in layer V. Most SST neurons were multipolar round/oval or stellate cells. No pyramidal neurons were found. Moreover, 2-color immunofluorescence revealed that only 33.50%, 24.05%, 16.73%, 0%, and 64.57% of SST neurons contained gamma-aminobutyric acid, calbindin-D28K, calretinin, parvalbumin, and calcium/calmodulin-dependent protein kinase II, respectively. In contrast, neuropeptide Y and nitric oxide synthase were abundantly expressed, with 80.07% and 75.41% in SST neurons, respectively. Our immunocytochemical analyses of SST with D1 and D2 dopamine receptors and choline acetyltransferase, α7 and β2 nicotinic acetylcholine receptors suggest that dopaminergic and cholinergic fibers contact some SST neurons. The results showed some distinguishable features of SST neurons and provided some insight into their afferent circuitry in the gerbil VC. These findings may support future studies investigating the role of SST neurons in visual processing.