Reappraisal of the baseline bone scan in breast cancer

Baseline staging bone scans in 1,267 consecutive women with breast cancer attending a single clinic between 1980 and 1986 were reviewed. 0.3% of patients with T1, 3% with T2, 8% with T3, 13% with T4 tumors and none of those with Stage 1, 3% with Stage 2, 7% with Stage 3, and 47% with Stage 4 disease had a positive scan due to bone metastases. Two hundred eight-nine (23%) had bone scan abnormalities secondary to radiologically confirmed benign bone disease. In 20 patients, no cause for a bone scan abnormality could be found after a median follow-up of 3.50 yr, a false-positive frequency of 1.6%. The false-negative rate was 0.08%. It is concluded that patients with tumors less than 2 cm are most unlikely to have a positive scan. In this instance, scans are not required routinely. However, we recommend a baseline scan in all patients with Stage 2, 3, or 4 disease.     

Chemotherapy of advanced breast cancer: outcome and prognostic factors.

The outcome for 758 consecutive patients who had received one or more chemotherapy regimens for recurrent or metastatic breast cancer is presented. The response rate following first line treatment was 34%. Median duration of response was 7.8 months, median time to progression was 3.7 months and median survival was 7.9 months. The only factor predicting for response, of factors recorded at presentation and at initiation of chemotherapy, was the use of anthracycline based regimens, though this may reflect the patient selection policy. Initial disease free interval, presence of liver metastases and use of anthracyclines were significantly related to time to progression. Several factors related to survival following first chemotherapy, but anthracycline usage showed only a very weak correlation. One third of patients (249/758) received two or more chemotherapy regimens. The response rate (16%) and median time to progression (2.3 months) were significantly worse than for first line treatment. The outcome after third line chemotherapy was very similar to that observed following second line treatment. Achievement of an objective response with first line chemotherapy predicted for second response, but with insufficient power to be of use in selecting patients for subsequent chemotherapy. Time to progression following first line chemotherapy did not influence that after second line treatment.     

Characterization of Group B Streptococcal Invasion of Human Chorion and Amnion Epithelial Cells In Vitro

Group B streptococci (GBS) have been cultured from the chorioamnionic membrane of pregnant women, usually in association with chorioamnionitis and premature labor (K. A. Boggess, D. H. Watts, S. L. Hillier, M. A. Krohn, T. J. Benedetti, and D. A. Eschenbach, Obstet. Gynecol. 87:779–784, 1996). Colonization and infection of placental membranes can be a prelude to neonatal GBS infections even in the presence of intact membranes (R. L. Naeye and E. C. Peters, Pediatrics 61:171–177, 1978), suggesting that GBS cause chorioamnionitis or establish amniotic fluid infections by partial or complete penetration of the placental membranes. We have isolated and grown cultures of primary chorion and amnion cells from human cesarean-section placentas. This has provided a biologically relevant model for investigating GBS adherence to and invasion of the two epithelial barriers of the placental membrane. GBS adhered to chorion cell monolayers to a high degree. Pretreatment of GBS with trypsin reduced adherence up to 10-fold, which suggested that the bacterial ligand(s) was a protein. GBS invaded chorion cells at a high rate in vitro, and invasion was dependent on cellular actin polymerization. GBS could be seen within intracellular vacuoles of chorion cells by transmission electron microscopy. We also demonstrated that GBS were capable of transcytosing through intact chorion cell monolayers without disruption of intracellular junctions. GBS also adhered to amnion cells; in contrast, however, these bacteria failed to invade amnion cells under a variety of assay conditions. GBS interactions with the chorion epithelial cell layer shown here correlate well with epidemiological and pathological studies of GBS chorioamnionitis. Our data also suggest that the amnion cell layer may provide an effective barrier against infection of the amniotic fluid.     

Using interactive videodisc to test advanced airway management skills

PURPOSE: To evaluate the effectiveness of the Actronics Interactive Learning System to teach the psychomotor skills of advanced airway management compared to the traditional method of lecture/demonstration. METHODS: The study was a nonrandomized, nonequivalent comparison group design of a convenience sample of 86 American Heart Association (AHA), advanced cardiac life support (ACLS) students, who obtained instruction in airway management by the interactive videodisc (IVD) learning system (n = 41), or by the traditional method of demonstration/return demonstration (n = 45). The evaluation criteria for the students were based on the number of attempts required to perform successfully endotracheal (ET) intubation and esophageal obturator airway (EOA) insertion. RESULTS: No statistically significant differences in the performance of ET insertion between the IVD and the traditional method of instruction could be demonstrated. However, initial certifiers for ACLS learning EOA insertion by the IVD method had a treatment effect (p = 0.004) compared to ACLS students learning by the traditional method. This treatment effect was not noted with ET intubation and EOA insertion for students seeking recertification. In a post-test satisfaction questionnaire, 34 IVD students reported satisfaction with learning airway management using this instructional method, but also expressed a preference to have an ACLS instructor available. CONCLUSION: This study highlights the role of IVD in teaching the complex skills of advanced airway management.     

Gunshot wounds to the facial nerve.

OBJECTIVE: This paper presents our experience with gunshot wounds to the temporal bone and discusses facial nerve lesions, surgical indication, surgical timing, and other findings. STUDY DESIGN: We performed a retrospective review of patients treated for facial nerve lesion after gunshot injury to the temporal bone. SETTING: The study was performed in the Otolaryngology Department of the University of Sao Paulo Medical School, Sao Paulo, Brazil. PATIENTS: Ninety-eight patients treated between 1988 and 1999 were analyzed. INTERVENTION: Facial nerve lesions, bullet locations, and surgical techniques were analyzed. Patients were monitored for 2 years. RESULTS: Gunshot trauma to the temporal bone presented considerable tissue loss resulting from the abrasion effect and severity of the impact. The third segment of the facial nerve was most affected, and the bullet was typically found lodged in the mastoid tip. Postoperative infection was common. Such cases required revision surgery, resulting in worse cosmetic outcomes than in cases of closed trauma. CONCLUSIONS: Surgical exploration of the facial nerve should be performed as soon as possible, since long delays increase the chance of traumatic neuroma and more pronounced scarring around the facial nerve. Open mastoidectomy with meatoplasty is the surgical technique recommended for repairing the mastoid and the facial nerve. In the majority of cases, a cable graft is necessary. Since nerve lesion in proximity to the stylomastoid foramen and extratemporal facial nerve is common, these areas must be explored carefully.     

Late incidence and determinants of stroke after aortic and mitral valve replacement

Background

Stroke is a devastating complication in patients with prosthetic valves, but characterization of its late occurrence from a large cohort is lacking.

Methods

Three thousand one hundred eighty-nine adult patients who underwent a total of 3,576 operations for left-heart valve replacement were managed with contemporary anticoagulation guidelines and prospectively followed in a dedicated clinic. Total follow-up was 20,096 patient years. Bootstrapped survival analysis was used to determine the impact of patient and valve related factors on the incidence of stroke.

Results

Most strokes were embolic. Linearized embolic stroke rates were 1.3% ± 0.2% per year for aortic bioprostheses, 1.4% ± 0.2% per year for aortic mechanical valves, 1.3% ± 0.3% per year for mitral bioprostheses, and 2.3% ± 0.4% per year for mitral mechanical valves (p = 0.002, vs other implant types). Age more than 75 years, female gender, and smoking were independent risk factors after aortic and mitral valve replacement. Atrial fibrillation, coronary disease, and tilting-disc mechanical prostheses were independent predictors of embolic stroke after aortic valve replacement. Preoperative left ventricular (LV) dysfunction was an independent risk factor in patients with mitral prostheses. Primary operative indication, diabetes, redo status, or the presence of two prosthetic valves were not associated with an increased hazard. The addition of acetyl salicylic or dipyridamole to warfarin anticoagulation did not significantly lower embolic stroke risk in patients with mechanical prostheses.

Conclusions

Approximately 20% of patients with valve prostheses have an embolic stroke by 15 years after valve replacement. Some risk factors such as the avoidance of smoking, mitral mechanical prostheses, aortic tilting-disc valves, and proceeding to mitral surgery before LV dysfunction occurs are potentially modifiable.     

Comparison of 64-slice cardiac computed tomography with myocardial perfusion scintigraphy for assessment of global and regional myocardial function and infarction in patients with low to intermediate likelihood of coronary artery disease

Background. Cardiac computed tomography (CCT) has the potential to assess both coronary anatomy and ventricular function in a single study. We examined the agreement between CCT and myocardial perfusion scintigraphy (MPS) for the assessment of global and regional ventricular function. Methods and Results. Research CCT was performed in 52 patients with a low to intermediate likelihood of coronary artery disease referred for MPS. Left ventricular enddiastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction (LVEF), and myocardial wall motion and thickening were compared between techniques. In addition, myocardial contrast attenuation on CCT was compared with radiotracer uptake on MPS. LVEF values agreed well (mean difference, 4.1%; SD, 15.13%), but CCT left ventricular end-diastolic volume was greater compared with MPS (mean difference, 46.0 mL; SD, 33.34 mL) (P<.001). There was moderate agreement for segmental myocardial motion and thickening, with κ values of 0.57 (95% confidence interval, 0.51–0.63) and 0.47 (95% confidence interval, 0.41–0.53), respectively. Seventeen patients had hypoattenuation in at least 1 myocardial segment on CCT. Three of four patients with concomitant abnormalities of wall motion and thickening on CCT had infarction in the same territory on MPS. Conclusions. There was good agreement for LVEF between CCT and MPS but myocardial volumes differed, and these modalities cannot be used interchangeably. Mild abnormalities of regional function are detected more commonly by CCT than by MPS. Myocardial hypoattenuation on CCT is highly specific for myocardial infarction when associated with reduction of systolic wall thickening and regional wall motion abnormality. Dr Nicol received a grant from the Defence Postgraduate Medical Deanery.     

Predictive factors of recurrence in adenocarcinoma of the esophagogastric junction in the multimodal era

IntroductionAdenocarcinoma of the esophagogastric junction (AEGJ) represents a poor prognostic tumor. We evaluated the recurrence pattern and risk factors associated with recurrence in patients undergoing surgical resection by AEJG.MethodsRecurrences were categorized as locoregional, peritoneal, or distant. These three recurrence groups and a non-recurrence group were compared, and overall survival (OS) and disease-free survival (DFS) for each one was obtained.ResultsWe analyzed 188 patients with curative surgical treatment. Recurrence was observed in 72 (38.3%) patients. Locoregional recurrence was observed in 17 (23.6%); 20 (27.8%) peritoneal recurrence and 35 (48.6%) distant metastasis. DFS was 9, 5, and 8 months, and OS was 21.8, 13.2, and 20.8, respectively. Tumors larger than 5 cm are risk factors for peritoneal recurrence (OR:2.88, p = 0.012). Positive lymph nodes were related to distant metastasis (OR:9.15, p = 0.040), and lymphatic invasion for locoregional recurrence (OR:3.81, p = 0.028).ConclusionAEGJ is associated with high rates of early recurrence.     

Mixed-integer quadratic programming for automatic walking footstep placement,duration, and rotation

This paper presents a mixed-integer model predictive controller for walking. In the proposed scheme, mixed-integer quadratic programs (MIQP) are solved online to simultaneously decide center of mass jerks, footsteps positions, durations, and rotations while respecting actuation, geometry, and contact constraints. Most walking controllers require preplanned footstep rotations to avoid dealing with the nonlinearity introduced by foot rotation decision. The main contribution of this work is an optimization formulation where feet rotations are automatically planned to attain a reference speed rotation. Finally, simulation results are shown to present and discuss the capabilities of the proposed formulation.