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Cerebral microgyria, thalamic cell size and auditory temporal processing in male and female rats 总被引:4,自引:2,他引:2
Herman AE; Galaburda AM; Fitch RH; Carter AR; Rosen GD 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(5):453-464
Induction of microgyria by freezing injury to the developing somatosensory
cortex of neonatal rats causes a defect in fast auditory processing in
males, but not in females. It was speculated that early damage to the
cortex has sexually dimorphic cascading effects on other brain regions
mediating auditory processing, which can lead to the observed behavioral
deficits. In the current series of experiments, bilateral microgyri were
induced by placement of a freezing probe on the skulls of newborn male and
female rats, and these animals were tested in adulthood for auditory
temporal processing. Control animals received sham surgery. The brains from
these animals were embedded in celloidin, cut in the coronal plane and the
following morphometric measures assessed: microgyric volume, medial
geniculate nucleus (MGN) volume, cell number, and cell size, and, as a
control, dorsal lateral geniculate nucleus (dLGN) volume, cell number and
cell size. There were no sex differences in the cortical pathology of
lesioned animals. However, microgyric males had more small and fewer large
neurons in the MGN than their sham-operated counterparts, whereas there was
no difference between lesioned and sham-operated females. There was no
effect on dLGN cell size distribution in either sex. Microgyric males were
significantly impaired in fast auditory temporal processing when compared
to control males, whereas lesioned females exhibited no behavioral
deficits. These results suggest that early injury to the cerebral cortex
may have different effects on specific thalamic nuclei in males and
females, with corresponding differences in behavioral effects.
相似文献
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The purpose of this study was to evaluate the gait responses of individuals with low vision compared to those of normal-visioned individuals when their vision is challenged by extreme levels of light. Twenty subjects with age-related maculopathy (ARM) and 20 subjects with normal vision first walked along a flat, unobstructed path immediately after the ambient light level was changed from low (5 lux) to high (2500 lux). The procedure was repeated after the light was reduced from the high to the low level. Muscle activity, temporal and kinematic variables, and ground reaction forces were used to detect gait characteristics because of ambient light level changes. Data suggested that ARM subjects walked slower and with more caution than normal subjects but that these differences were not related to ambient light level. Head angle, an estimate of gaze direction, was lower for ARM subjects during high light, but the gaze direction for both groups was low during low light. Among these ARM subjects, extreme levels of ambient light did not affect gait; subjects made adaptations that were reasonable to encourage safe ambulation, despite the direction of light change. Normal-visioned individuals in this study experienced more difficulty in low light than high light situations. 相似文献
116.
AE Kark MD FRCS JC McAlpine MB FRCPath 《International journal of clinical practice》1994,48(4):216-217
SUMMARY A hazard associated with eating raw fish is presented. The larval nematode Anisakis marina (‘herring worm‘) is a recognised public health problem in Japan, and cases have been reported in the UK. The intestinal burrowing of the larval form causes acute abdominal symptoms clinically resembling acute appendicitis. Operation is required; no antiparasitic agent is available. 相似文献
117.
Miller DL; Simmons JT; Chang R; Ward BA; Shawker TH; Doppman JL; Chang AE 《Radiology》1987,165(3):785-790
A prospective, blinded comparison of three methods of hepatic contrast enhancement in computed tomography (CT) was conducted in 15 patients with colorectal carcinoma metastatic to the liver. Arterial portography (AP-CT) was performed with injection of contrast material into the superior mesenteric artery during CT. Delayed scanning (DS-CT) was performed 4 hours after intravascular administration of contrast material (mean dose, 280 mL). CT with an ethiodized oil emulsion (EOE-CT) was performed 1 hour after slow intravenous infusion of the emulsion. All patients underwent laparotomy following imaging studies. A lesion-by-lesion analysis of 56 metastases showed no significant differences in sensitivity (AP-CT, 77%; DS-CT, 83%; EOE-CT, 82%), but the false-positive rate for AP-CT was significantly higher than that for DS-CT (P less than .001) or EOE-CT (P less than .01). False-positive rates for EOE-CT and DS-CT were not significantly different. The predictive value of a positive test was 63% for AP-CT, 90% for DS-CT, and 81% for EOE-CT. AP-CT does not appear to be clinically useful for detection of hepatic metastases because of the high false-positive rate. No difference could be demonstrated between DS-CT and EOE-CT. DS-CT is a valuable method for hepatic contrast enhancement. 相似文献
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The cardinal features of Kabuki (Niikawa-Kuroki) syndrome (KS) include characteristic facial dysmorphic features, mild to moderate mental deficiency, skeletal abnormalities, dermatoglyphic abnormalities, and postnatal growth retardation. We identified 8 patients with KS in a genetics clinic over the past 5 years. All were Caucasians, except for 2 who were of mixed Aboriginal and Caucasian descent. All had the facial gestalt, the dermatoglyphic abnormalities characteristic of the syndrome, and developmental delay. Dental abnormalities of permanent teeth were seen in all 8 cases; 6 had missing lower incisors. Five patients had uniquely abnormal upper incisor teeth shape; the upper incisors had a 'flat head' screwdriver-shaped appearance. Other dental abnormalities included missing lower lateral incisors, missing second premolars, and ectopic upper 6-year molars. We believe the presence of the unique dental findings will prove useful in the diagnostic assessment of individuals with KS. 相似文献
120.
E Sarifakioglu† AE Yilmaz‡ C Gorpelioglu† 《Journal of the European Academy of Dermatology and Venereology》2008,22(6):741-744
Aims To investigate the frequency and the nature of nail alterations in infants. Study design A total of 250 infant patients from newborn to 2 years of age were evaluated from the outpatient clinics of paediatrics and dermatology departments, Fatih University Hospital. The nail alterations were documented. The data were presented as percentages, and for categorical comparisons, Chi‐squared or Fisher's Exact test were used. P < 0.05 was considered statistically significant. Results Of the 250 infant patients, nail alterations were seen in only 17 (6.8%). Most of the patients had toe nail involvement. In 12 of 17 (70.6%) infants, there was one type of nail alteration; in 4 of 17 (23.5%) infants, there was two type of nail alterations; and in 1 of 17 (5.9%) infants, there was three type of nail alterations. The most frequent diagnosis was onychoschizia in 6 of 17 (2.4%) and congenital hypertrophy of the lateral nail fold together with ingrown nail in 6 (2.4%) infants. Conclusion Because nail alterations could be a manifestation of systemic or dermatologic diseases in infants, fingernail and toenail examination should be a part of the paediatric dermatology examination. 相似文献