Transxiphoid approach without median sternotomy for the repair of atrial septal defects

BACKGROUND: Interest in minimally invasive procedures has recently increased because it results in less surgical trauma, decreased patient discomfort, short hospital stay, reduced costs, and better cosmetic appearance. Based on these facts, we have been using the transxiphoid process approach without sternotomy for the correction of atrial septal defects. METHODS: From July 1996 to January 1997, the xiphoid process window approach was performed in 10 patients with ostium secundum atrial septal defect. Ages ranged from 6 months to 14 years (mean, 5.3 years). In all patients, extracorporeal circulation was carried out by means of cannulation of the femoral artery and both caval veins and of aortic cross-clamping. Videothoracoscopy was used to improve visualization of the aorta. RESULTS: There were no intraoperative or postoperative complications, and in all but 1 patient, extubation was possible while in the operating room. CONCLUSIONS: The xiphoid process window, with no median sternotomy, permitted closure of the atrial septal defects with good results and could be used as a less invasive technique for their correction.     

erbB-2, p53, and efficacy of adjuvant therapy in lymph node-positive breast cancer

BACKGROUND: We have previously reported that high expression of the erbB-2 gene (also known as HER-2/neu and ERBB2) in breast cancer is associated with patient response to dose-intensive treatment with cyclophosphamide, doxorubicin (Adriamycin), and 5-flurouracil (CAF) on the basis of short-term follow-up of 397 patients (set A) with axillary lymph node-positive tumors who were enrolled in Cancer and Leukemia Group B (CALGB) protocol 8541. METHODS: To validate those findings, we conducted immunohistochemical analyses of erbB-2 and p53 protein expression in an additional cohort of 595 patients (set B) from CALGB 8541, as well as a molecular analysis of erbB-2 gene amplification in tumors from all patients (sets A and B). Marker data were compared with clinical, histologic, treatment, and outcome data. RESULTS: Updated analyses of data from set A (median follow-up, 10.4 years) showed an even stronger interaction between erbB-2 expression and CAF dose, by use of either immunohistochemical or molecular data. A similar interaction between erbB-2 expression and CAF dose was observed in all 992 patients, analyzed as a single group. However, for set B alone (median follow-up, 8.2 years), results varied with the method of statistical analysis. By use of a proportional hazards model, the erbB-2 expression-CAF dose interaction was not significant for all patients. However, in the subgroups of patients randomly assigned to the high- or the moderate-dose arms, significance was achieved. When patient data were adjusted for differences by use of a prognostic index (to balance an apparent failure of randomization in the low-dose arm), the erbB-2 expression-CAF dose interaction was significant in all patients from the validation set B as well. An interaction was also observed between p53 immunopositivity and CAF dose. CONCLUSIONS: The hypothesis that patients whose breast tumors exhibit high erbB-2 expression benefit from dose-intensive CAF should be further validated before clinical implementation. Interactions between erbB-2 expression, p53 expression, and CAF dose underscore the complexities of predictive markers where multiple interactions may confound the outcome.     

Myofibroblasts and retinal fibrovascular membranes

Black-pigmented bacteria (BPB) have been associated with infections of endodontic origin. The purpose of this study was to culture and identify BPB from the apical and coronal segments of infected root canals to understand better their ecological relationships. Teeth with a periapical radiolucency were extracted and immediately placed in reduced transport fluid for transport to an anaerobic chamber. Of 18 sampled roots, 12 were positive for the growth of BPB. Eight of the 12 roots with BPB had a carious exposure of the pulp chamber. Seven roots had Prevotella nigrescens in both the apical and the coronal segments. Six of these seven teeth had carious exposures of the pulp chamber. Of the 12 roots infected with BPB, six roots had two different species of BPB, with P. nigrescens always being one of the species. P. nigrescens was the most often isolated BPB from both the coronal and apical segments of infected root canals.     

Evidence that physiologic levels of circulating estrogens and neonatal sex-imprinting modify postpubertal hepatic microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase activity

Intact, but sham-operated female rats had 2- to 3-fold higher levels of hepatic 3-hydroxy-3-methylglutaryl CoA reductase activity than their male counterparts (15--21.5 vs. 6.7--8.7 nmol mevalonate/mg protein per h). The activity of the hepatic enzyme declined to about the same relative degree (40--60%) in male and female rats that were gonadectomized after puberty (53 days of age) and killed 5 weeks later. Implantation of silastic capsules containing 17 beta-estradiol increased the level of hepatic 3-hydroxy-3-methylglutaryl CoA reductase to levels found in sham-operated controls. In rats that were gonadectomized in infancy (12 h old) and killed 7--8 weeks later, the level of enzyme activity was not altered in females, but it was increased from 60--240% in males. Consequently, following neonatal gonadectomy, male-female differences in enzyme activity were no longer apparent. Implantation of silastic capsules containing estradiol in neonatally gonadectomized rats resulted in a doubling of enzyme activity in both males and females. Ovariectomy reduced plasma estrogen levels, but implantation of estradiol in gonadectomized males and females increased the hormone level to that found in sham-operated females. Thus, the results strongly suggest a role for physiologic levels of estrogen as a positive effector of 3-hydroxy-3-methylglutaryl CoA reductase activity. Neonatal sex imprinting also appears to modulate the enzyme activity since sex-mediated differences are effaced by gonadectomy in infancy, but not by gonadectomy following puberty.     

Compensation for Distortion in Eye-Movement Monitors

A compensation scheme for the correction of both horizontal and vertical eye position measurements is developed. Based on the assumption that the distortion process can be modeled as piecewise linear, a new sample point structure is introduced. This structure permits both fixation-based and tracking-based sampling strategies. It also provides a convenient method for partitioning a display for estimation purposes. A minimum mean squared error estimate for the regional linear functions is derived. The problem of measurement assignment to linear regions is solved using a weighted distance metric. Performance is given both in terms of estimation error and the error remaining after correction for a test pattern. Results are presented for a specific example.     

Baller-Gerold syndrome craniosynostosis-radial aplasia syndrome

A new case of the Baller-Gerold syndrome is described in a 6 1/2-year-old, black male who presented at birth with bilateral synostoses of the coronal and lambdoidal sutures, bilateral radial aplasia, vertebral anomalies and genito-urinary malformations. The parents and siblings were unaffected, and there was no history of consanguinity. A review of the history and physical findings in our patient and in the four other patients previously reported in the literature is provided, with a discussion on pathogenesis, prognosis and the possible autosomal recessive mode of inheritance of the syndrome.