Tandem hetero diels-alder reaction: synthesis of oxygenated macrocycles.

[structure: see text]. C2-symmetric, oxygenated macrocycles have been synthesized from simple acyclic precursors in a single step by a tandem hetero Diels-Alder reaction. Thermolysis and Lewis acid catalysis can effect this novel transformation. The tandem reaction product is formed in preference to the intramolecular cycloaddition product, and an explanation for this result is proposed.

Early intervention and school nursing practice.

The most vital and critical period for early intervention is in the first 3 years of life. The school nurse working in an early childhood program plays a pivotal role in assessing and meeting the health and developmental needs of very young children and their families. This article discusses early intervention, as defined by federal law, as an age-related service delivered within a family-focused, multidisciplinary, interagency, and collaborative model. An assessment framework for school nurses working with this population is described, which includes physical, social, and emotional domains. Identifying children early and then providing needed interventions and services will assist at-risk children in realizing their developmental potential.

Rupture of the flexor pollicis longus tendon after 30 years due to migration of a retained foreign body.

Delayed rupture of a flexor tendon in the hand due to the presence of a retained foreign body is rare. We present the case of a late flexor pollicis longus rupture 30 years after traumatic implantation of a glass fragment. The foreign body had migrated distally a distance of 4.5 cm from the site of the original injury and eroded into the flexor tendon sheath. Thumb function was restored with a flexor digitorum superficialis tendon transfer from the ring finger with excellent results.

Ultrasonic appearance of mammary carcinoma with a dedicated whole-breast scanner.

Forty-four pathologically proved mammary carcinomas were studied by clinical examination, xeroradiography, and ultrasonography with a dedicated whole-breast scanner. Abnormalities reflecting carcinoma were shown by echography in 90% of cases and xeromammography in 97%. Ultrasonic manifestations of malignancy were separated into four categories: (a) a solid, hypoechoic mass; (b) a hyperechoic focus; (c) an irregular, echogenic zone of parenchymal disruption; and (d) an atypical cystic mass. Dedicated ultrasound instruments enhance interpretation and improve differential diagnostic capability. Sonography demonstrates abnormalities better and permits superior definition of abnormal characteristics in a dysplastic breast than in a fatty, atrophic breast, while xeromammography may be more reliable in postmenopausal women with fatty breasts than in women with mammographically dense breasts. One limitation of current ultrasound equipment is the inability to consistently demonstrate microcalcification.

Automated sonomammographic-xeromammographic-pathologic correlations in the assessment of carcinoma of the breast.

Automated sonomammography and xeromammography were compared in a group of 293 patients referred for a variety of symptomatic and asymptomatic conditions. Twenty of the 293 patients had mammographic evidence of carcinoma that was confirmed pathologically. Seventeen of these patients had sonomammographic evidence of a solid mass; 11 of these demonstrated signs of malignancy, such as irregular border, and desmoplastic reaction manifested by thickening of Cooper's ligaments, skin retraction, periductal fibrosis or disruption of architecture. Statistical analysis of the results reveals that a high degree of sensitivity and specificity in the diagnosis of malignant breast disease can be accomplished with automated sonomammography.

Ultrasound of the whole breast utilizing a dedicated automated breast scanner.

Innovations in design of a dedicated breast scanner resulted in automation of the scanning process, the production of high resolution images of the whole breast and an efficient mode of image review. The results of clinical evaluation of the prototype of this breast scanner investigating normal breasts as well as benign and malignant breast lesions are presented.