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111.
The majority (217/325, 66%) of the neurons in the middle temporal (MT)
area/V5 show strong antagonistic surrounds, defined here by a decrease of
at least 50% in the summation curve. We mapped the antagonistic surround in
145 such cells, using eight circularly distributed surround stimulus
patches (Surround Asymmetry Test, SAT) and also mapped the surround in 51
of these 145 cells using a grid consisting of 25 square patches (Surround
Mapping Test, SMT). Both tests showed that the angular surround
distribution was non-uniform in the majority of these neurons. In half the
neurons, the antagonistic surround was asymmetric, and arose from a single
region on one side of the excitatory receptive field (ERF). In another
quarter of the sample the surround was bilaterally symmetric, and arose
from a pair of regions on opposite sides of the ERF. Only the remaining 20%
showed a circularly symmetric surround distribution. These three groups
differed in their laminar distribution. The SMT showed that, radially, the
surround antagonism reached a maximum, on average, at 1.5 times the ERF
radius. Detailed comparisons of the spatial relationships of excitatory and
inhibitory regions of the RF components shows that non-homogeneity of the
surround influence appears to be an intrinsic property of the surround.
Such a property may underly the extraction of the surface orientation and
curvature from speed patterns.
相似文献
112.
This study in a rabbit model simulates contamination with glove powder in association with a routine gynaecological examination. Large individual variations of powder contamination were found and there were no overall statistically significant differences between the control and experimental animals. The findings are supported by the observation that some but not all women develop adhesions after gynaecological surgery. Analyzes of variances indicate differences in the migration of starch particles in the genital tract with the highest amount of particles found three days after starch contamination of the vagina. Since no adhesions were observed, there would probably need to be an ongoing post surgical or post infectious inflammation in the tissue, when the starch particles are added. Starch powder from latex gloves can cause adhesions and increase the risk of latex allergy in healthcare workers. Retrograde migration in the genital tract cannot be excluded, powdered examination products should be eliminated from the gynecologicla examination room. 相似文献
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114.
Breast specimen radiography: evaluation of a compression device 总被引:1,自引:0,他引:1
The irregular shape and uneven tissue thickness of excised breast specimens makes radiographic evaluation difficult, especially when calcifications are not present. Xeroradiographs before and after compression of 20 separate excised breast specimens were compared, and 17 of the same specimens were compared after compression combined with immersion in water. Specimen compression improved visibility of the lesion on average in 88% of cases, and visibility was equal in 12%. Combined compression/immersion further improved visibility of the lesion on average in 37% of cases. More significantly, evaluation of the compressed specimen led to a change in interpretation of the radiographs in 45% of cases. Compression of the specimen in specimen radiography is recommended in all cases in which pre-biopsy localization is performed. 相似文献
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Increased numbers of eosinophilic granulocytes and eosinophil degranulation have been observed in various inflammatory conditions. Biopsies from the fallopian tubes of 28 patients were examined for the content of eosinophilic granulocytes. Peritoneal fluids (PF) from 89 patients were analyzed for the concentrations of eosinophilic granulocytes and the granule protein eosinophil cationic protein (ECP). The ECP levels in the PF were substantially elevated during genital inflammation (P < 0.001). Furthermore, one week after laparotomy for adhesiolysis there were both increased PF-ECP levels (P < 0.01) and raised concentrations of eosinophilic granulocytes (P < 0.001) when compared to the reference group. Staining of the biopsies with monoclonal antibodies revealed an increased total number as well as a number of activated eosinophilic granulocytes in specimens from adhesions and sactosalpinx compared to specimens from normal fimbriae. The findings indicate that eosinophilic granulocytes may have a possible role in the fibrotic process of pelvic adhesion disease. 相似文献
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120.
Dunnick NR; Carson CC; Braun SD; Miller GA; Cohan R; Degesys GE; Illescas FF; Newman GE; Weinerth JL 《Radiology》1985,157(1):51-55
In 224 patients, renal stones were removed from the urinary tract using either direct extraction with a basket or forceps (59 patients), ultrasonic lithotripsy (164 patients), or infusion chemotherapy (one patient). Residual stone fragments were present more frequently in patients treated with ultrasonic lithotripsy (27%) than with direct extraction (5%). Other complications included hemorrhage (eight patients), catheter dislodgement (four patients), large amounts of urine extravasation (three patients), glycine ascites (three patients), infection (two patients), pneumothorax (one patient), and a prolonged ileus (one patient). More complications occurred among the first 50 patients than the last 50 patients, even though more difficult cases, including patients with staghorn calculi, were accepted during the latter period. Although a learning curve exists, complications can be minimized by attempting to treat more favorable cases during the initial experience. 相似文献