Suppression of the tumorigenic phenotype of a rat liver epithelial tumor cell line by the p11.2–p12 region of human chromosome 11

Comparative chromosomal mapping studies and investigations of tumor-associated chromosomal abnormalities suggest that the development of hepatic tumors in humans and rats may share a common molecular mechanism that involves inactivation of the same tumor suppressor genes or common genetic loci. We investigated the potential of human chromosomes 2 and 11 to suppress the tumorigenic phenotype of rat liver epithelial tumor cell lines. These tumor cell lines (GN6TF and GP7TB) display elevated saturation densities in culture, efficiently form colonies in soft agar, and produce subcutaneous tumors in 100% of syngeneic rat hosts with short latency periods. Introduction of human chromosome 11 by microcell fusion markedly altered the tumorigenicity and the transformed phenotype of GN6TF cells. In contrast, the tumorigenic potential and phenotype of GP7TB cells was unaffected by the introduction of human chromosome 11, indicating that not all rat liver tumor cell lines can be suppressed by loci carried on this chromosome. Introduction of human chromosome 2 had little or no effect on the tumorigenicity or cellular phenotype of either tumor cell line, suggesting the involvement of chromosome 11–specific loci in the suppression of the GN6TF tumor cell line. The GN6TF-11^neo microcell hybrid cell lines displayed significantly reduced saturation densities in monolayer cultures, and their ability to grow in soft agar was completely inhibited. Although GN6TF-11^neo cells ultimately formed tumors in 80–100% of syngeneic rat hosts, the latency period for tumor formation was much longer. Molecular characterization of GN6TF-11^neo microcell hybrid cell lines indicated that some of the clonal lines had spontaneously lost significant portions of the introduced human chromosome, partially delineating the chromosomal location of the putative tumor suppressor locus to the region between the centromere and 11p12. Molecular examination of microcell hybrid–derived tumor cell lines further defined the minimal portion of human chromosome 11 capable of tumor suppression in this model system to the region 11p11.2-p12. © 1995 Wiley-Liss, Inc.     

Intracardiac teratoma in an infant

Summary We report the only infant known to us who has survived surgery for a primary right ventricular teratoma. Included is a review of other reported cases of teratoma of the heart in infancy and childhood.     

Fetal Responses to Vibrotactile Stimulation, A Possible Predictor of Fetal and Neonatal Outcome

Summary: This study measured the antenatal fetal heart rate changes in response to a single vibrotactile stimulus. In a group of 11 normal patients, this resulted in a significant change in the fetal heart rate (P < 0.001). Sixty-eight high risk patients were also tested. In the group of 25 patients whose fetuses showed no response to the stimulus, there were 4 stillbirths and 4 neonatal deaths; 23 of these 25 infants were small for gestational age (SGA) compared to only 15 of the 43 that showed a response to the stimulus.
Fetal habituation to a repeated vibrotactile stimulus was measured in a control group of 40 patients who had a normal antepartum and intrapartum course and delivered infants in an optimal condition. The same was done in a study group of 48 patients who delivered infants that were SGA. These infants were assessed at 1 year of age by the Griffiths Mental Developmental Scale (GMDS). Infants that were SGA did not differ significantly from the control group. However, infants who had a normal antenatal habituation pattern had a significantly better performance (P < 0.01) compared to infants who had an abnormal antenatal habituation pattern.     

Patient positioning and port placement for bilateral hand-assisted laparoscopic nephrectomy

Hand-assisted laparoscopic nephrectomy is an alternative to laparoscopic nephrectomy. We describe our method for triangular port placement and patient positioning during bilateral hand-assisted laparoscopic nephrectomy. This method does not require intraoperative patient repositioning and may decrease the overall operative time while enhancing patient safety.     

American College of Cardiology/American Heart Association preoperative assessment guidelines reduce resource utilization before aortic surgery

BACKGROUND: Methods used for evaluation of cardiac risk before noncardiac surgery vary widely. We evaluated the effect over time on practice and resource utilization of implementing the American College of Cardiology/American Heart Association Guidelines on Preoperative Risk Assessment. METHODS: We compared 102 historical control patients who underwent elective abdominal aortic surgery (from January 1993 to December 1994) with 94 consecutive patients after guideline implementation (from July 1995 to December 1996) and 104 patients in a late after guideline implementation (from July 1, 1997, to September 30, 1998). Resource use (testing, revascularization, and costs) and outcomes (perioperative death and myocardial infarction) were examined. Patients with and without clinical markers of risk for perioperative cardiac complications were compared. RESULTS: The use of preoperative stress testing (88% to 47%; P <.00001), cardiac catheterization (24% to 11%; P <.05), and coronary revascularization (25% to 2%; P <.00001) decreased between control and postguideline groups, respectively. These changes persisted in the late postguideline group. Mean preoperative evaluation costs also fell ($1087 versus $171; P <.0001). Outcomes of death (4% versus 3% versus 2%) and myocardial infarction (7% versus 3% versus 5%) were not significantly different between control, postguideline, and late postguideline groups, respectively. Stress test rates were similar for patients at low risk versus high risk in the historical control group (84% versus 91%; P =.29) but lower for patients at low risk after guideline implementation (31% versus 61%; P =.003). CONCLUSION: Implementation of the American College of Cardiology/American Heart Association cardiac risk assessment guidelines appropriately reduced resource use and costs in patients who underwent elective aortic surgery without affecting outcomes. This effect was sustained 2 years after guideline implementation.     

Development of efficient threshold strategies for frequency doubling technology perimetry using computer simulation

PURPOSE: To develop new test procedures for frequency-doubling technology (FDT) perimetry that improve performance beyond those currently used. METHODS: Two novel threshold estimation procedures were evaluated: a rapid, efficient binary search technique (REBS) and a maximum-likelihood estimation (ZEST) procedure. A computerized visual field simulation model was developed to determine the accuracy and efficiency of these procedures. This model was constructed using previously derived characteristics of FDT perimetry from both normal observers (n = 506) and those with glaucomatous visual field loss (n = 352). The computer simulation program was used to determine the best parameters for the two new procedures and the effect of variability and response errors on algorithm performance. Comparisons were made to the performance of the modified binary search (MOBS) procedure used in the current commercial implementation of the FDT perimeter. RESULTS: Both the optimized REBS and ZEST procedures approximately halved the time required for FDT threshold testing without loss of accuracy or reproducibility. CONCLUSIONS: With suitable parameter choices, comparable performance was achieved using either ZEST or REBS. Simulation results indicate that accurate thresholds can be measured with an optimized ZEST or REBS procedure in approximately half the time required by traditional estimation methods.     

Progression of visual field loss in untreated glaucoma patients and glaucoma suspects in St. Lucia,West Indies

PURPOSE: A 1986-1987 survey found 8.8% prevalence of open-angle glaucoma in the black population of St. Lucia, West Indies. This follow-up study assessed visual field loss progression in untreated glaucoma patients and glaucoma suspects 10 years later. DESIGN: Cohort study. METHODS: Subjects were 205 glaucoma patients and suspects; 1987 data included age, sex, visual acuity, and visual fields measured by automated threshold perimetry (Humphrey C 30-2 test), and 1997 data included intraocular pressure, visual acuity, and visual fields measured by the same test. Exclusion criteria included field unreliability, field improvement due to vision improvement, nonglaucomatous vision deterioration, glaucoma treatment since 1988, and scoring of a visual field as end stage in 1987. Visual fields were scored by algorithms for the Advanced Glaucoma Intervention Study (AGIS) and Collaborative Initial Glaucoma Treatment Study (CIGTS). RESULTS: By AGIS criteria, 55% of 146 right eyes and 52% of 141 left eyes showed progression of visual field loss. In linear regressions, progression severity was unassociated with sex, intraocular pressure, or baseline visual field score, but was positively associated with age (P <.001, right; P =.002, left). The cumulative probability of reaching end stage in 10 years in at least one eye was approximately 16% by AGIS criteria. By CIGTS criteria, 73% of 146 right eyes and 72% of 141 left eyes progressed. CONCLUSIONS: These data provide a unique opportunity to study progression of untreated glaucoma. The percentage of eyes showing visual field loss progression and the percentage reaching end stage were considerably higher than in studies of visual field progression in treated eyes.