Preoperative testing before carotid endarterectomy: a survey of vascular surgeons' attitudes.

Traditional surgical practice and published consensus statements from major vascular surgery specialty societies have considered contrast arteriography to be a routine part of the diagnostic evaluation prior to carotid endarterectomy (CEA). However, some surgeons now omit routine preoperative arteriography if a technically adequate carotid duplex scan is performed and indications for CEA are clear. To better establish current practice patterns and to characterize vascular surgeons' opinions about the role of preoperative arteriography, the Peripheral Vascular Surgery Society membership was surveyed by mail. Eighty-six percent of the members responded (430 of 502). Ninety-three percent of all patients considered for CEA are evaluated with duplex scanning; 82% with arteriography. While the majority of surgeons typically obtain both a duplex scan and an arteriogram, 70% have performed CEA without a preoperative arteriogram. Brain imaging studies (CT or MRI) are obtained in 26% and MR angiograms in 10% of cases. Seventy-five percent of the surgeons agreed with the statement that CEA without preoperative arteriography is an acceptable practice if appropriate indications for surgery are present. Furthermore, one third believed that CEA without a preoperative arteriogram is generally acceptable (acceptable more than half the time). Respondents were stratified by surgical experience time in practice and practice type. No significant differences in responses were found, suggesting the acceptance of CEA without preoperative arteriography is broad-based. This survey demonstrates changing attitudes among practicing vascular surgeons regarding the necessity for routine arteriography prior to CEA. Carotid endarterectomy on the basis of duplex scanning and clinical assessment should be considered an accepted alternative.

The use of an invented language rule in the differentiation of normal and language-impaired Spanish-speaking children.

The purpose of the present study was to determine whether the results of a language-teaching procedure could be used to identify specific language-impaired children in a group of bilingual children with limited English proficiency (LEP). An invented morpheme was taught to two groups of LEP children who had been previously identified as normal and specific language-impaired. The language-impaired group learned the morpheme at a slower rate than the normal children, thus allowing the two groups to be differentiated. The approach promises to circumvent many of the obstacles that impede current practices for identifying language impairment in the LEP population.

Isolation and characterization of coaggregation-defective mutants of Veillonella atypica.

Spontaneously occurring coaggregation-defective mutants of Veillonella atypica PK1910 were isolated and used to study the interactions of veillonella with Streptococcus sanguis, Strep. gordonii and Strep. SM. Three classes of mutants were isolated. The first class failed to participate in lactose-inhibitable coaggregations with streptococcal cells. The second class of mutants failed to coaggregate by the lactose-non-inhibitable interactions. The third group, isolated from the first group, failed to coaggregate with any of the oral streptococci. Based on the coaggregation phenotypes of these mutants, a model for veillonella-streptococcal coaggregations is proposed, in which two distinct surface molecules mediate three types of interactions with the oral streptococci.