Ductal carcinoma in situ of the breast: correlation of pathologic and mammographic features with extent of disease

Optimal treatment of ductal carcinoma in situ (DCIS) of the breast requires an improved understanding of its pathologic extent and propensity for local recurrence. This study was performed to analyze mammographic and pathologic features of DCIS that might predict the extent of disease within the breast and facilitate treatment selection between lumpectomy alone, lumpectomy and radiotherapy, and mastectomy. At our institution, 60 cases of DCIS were diagnosed in 59 patients from June 1985 to February 1995 and form the basis of this retrospective study. Demographic and treatment-related information was obtained from hospital and tumor registry records. Mammograms were reviewed and size estimates of the abnormalities were determined. Pathologic slides from all cases were reviewed and classified according to size group, focality, nuclear grade, necrosis, and histologic subtype. DNA ploidy status and proliferation indices were available for 28 patients. Pathologically, 43 (72%) cases were < 15 mm, 14 (23%) were 16 to 40 mm, and 3 (5%) were > 40 mm. Five (8%) of the lesions were multicentric, 28 (47%) focal, and 27 (45%) multifocal. Thirty-three (55%) patients were treated by mastectomy, 16 (27%) by lumpectomy alone, and 11 (18%) by lumpectomy and radiation therapy. Mammographic size, histologic grade, presence or absence of necrosis, histologic subtype, DNA ploidy, and proliferative index were compared with pathologic size and focality by chi 2 analysis. Mammographic size correlated significantly with pathologic size (chi 2 = 11.3; P = 0.02) but underestimated the extent of disease in 9 cases. Although focality correlated significantly with pathologic size (chi 2 = 15.8; P = 0.003), the remaining histopathologic features did not significantly correlate with pathologic size or focality. Histopathologic features, including DNA studies, do not reliably predict the pathologic extent of DCIS, but mammographic size and focality do significantly correlate with pathologic size. Nevertheless, most cases of DCIS are small focal or multifocal lesions that are amenable to breast conservation approaches; further studies are needed to determine the appropriate use of lumpectomy, radiation therapy, and mastectomy in the treatment of DCIS.     

Couvelaire uterus

Uteroplacental apoplexy is a rare but nonfatal complication of severe forms of placental abruption. It occurs when vascular damage within the placenta causes hemorrhaging that progresses to and infiltrates the wall of the uterus. It is a syndrome that can only be diagnosed by direct visualization or biopsy (or both). For this reason, its occurrence is perhaps underreported and underestimated in the literature. The subject of this report is a 24-year-old pregnant woman who had a placental abruption an in whom classic uteroplacental apoplexy was diagnosed at the time of her cesarean section.     

Mathematical and computational models of drug transport in tumours

The ability to predict how far a drug will penetrate into the tumour microenvironment within its pharmacokinetic (PK) lifespan would provide valuable information about therapeutic response. As the PK profile is directly related to the route and schedule of drug administration, an in silico tool that can predict the drug administration schedule that results in optimal drug delivery to tumours would streamline clinical trial design. This paper investigates the application of mathematical and computational modelling techniques to help improve our understanding of the fundamental mechanisms underlying drug delivery, and compares the performance of a simple model with more complex approaches. Three models of drug transport are developed, all based on the same drug binding model and parametrized by bespoke in vitro experiments. Their predictions, compared for a ‘tumour cord’ geometry, are qualitatively and quantitatively similar. We assess the effect of varying the PK profile of the supplied drug, and the binding affinity of the drug to tumour cells, on the concentration of drug reaching cells and the accumulated exposure of cells to drug at arbitrary distances from a supplying blood vessel. This is a contribution towards developing a useful drug transport modelling tool for informing strategies for the treatment of tumour cells which are ‘pharmacokinetically resistant’ to chemotherapeutic strategies.     

Droplet evaporation: Effects of transients and variable properties

A numerical study of the effects of transients and variable properties on single droplet evaporation into an infinite stagnant gas is presented. Sample calculations are reported for octane droplets, initially at 300°K with R_o = 0·1, 0·5, 2·5 × 10^?4m, evaporating into air at temperatures and pressures in the ranges 600–2000°K and 1–10 atm, respectively. It is found that initial size R_o is eliminated from the problem on scaling time with respect to R²₀ and that the evaporative process becomes quasi-steady with ($\text{R}\text{R}{}_0\text{)}{}^2\text{= (}\text{R1}{}_0\text{R}{}_0\text{)}{}^2\text{?}\text{βt}\text{R}{}^2{}_0$, as suggested by experiment. Comparisons of solutions using various reference property schemes with those for variable properties show that best agreement obtains using a simple $\text{1}\text{3}$ rule wherein properties are evaluated at $\text{T}{}_{\mathrm{r}}\text{= T}{}_{\mathrm{s}}\text{+}\text{(T}{}_{\mathrm{e}}\text{?T}{}_{\mathrm{s}}\text{)}\text{3}$ and $\text{m}{}_{\mathrm{1,r}}\text{= m}{}_{\mathrm{1,s}}\text{+}\text{(m}{}_{\mathrm{1,e}}\text{? m}{}_{\mathrm{1,s}}\text{)}\text{3}$. The effects of temporal storage of mass species, energy, etc. and radial pressure variations in the vapor phase prove to be negligible, the early transient behavior being solely due to sensible heat effects within the droplet and related variations in vapor-side driving forces.     

Emission characteristics of photonic crystal light-emitting diodes

Experimentally measured optical properties of photonic crystal LEDs are reported here. Photonic crystal and photonic quasi-crystal structures were fabricated on GaN epilayer LED wafer material using both direct-write electron beam lithography and nanoimprint lithography. Some of these structures were processed to make finished LEDs. Both electroluminescence and photoluminescence measurements were performed on these structures. Devices were characterized for their current-voltage characteristics, emission spectra, far-field emission pattern, and angular emission pattern. These results are useful for fabricating photonic crystal LEDs and assessing their operational properties.     

Determination of ceftiofur and its desfuroylceftiofur-related metabolites in swine tissues by high-performance liquid chromatography

2- and 4-Nitrophenyl beta-D-xylopyranosides (4 and 5) were transformed, via dibutyltin oxidemediated acylation, into the corresponding 2,3-di-O-benzoyl derivatives 11 and 15. Xylobiose and xylotriose were easily isolated by charcoal column chromatography from a commercially available material and converted into the di- and trisaccharide methyl 1-thio-beta-glycosides 36 and 37. The 2-and 4-nitrophenyl beta-glycosides of the beta-(1-->4)-D-xylo-oligosaccharides of dp 2-4 were synthesized by N-iodosuccinimide-silver triflate-promoted condensation using 11 and 15 as the glycosyl acceptors and ethyl 1-thio-beta-D-xylopyranoside triacetate 16, 36, and 37 as the glycosyl donors. Also described are an improved preparation of 4 and 5, and the synthesis of 1-naphthyl beta-D-xylopyranoside, as well as an alternative approach to the 2- and 4-nitrophenyl beta-xylobiosides.     

Assessment of Soil Moisture Dynamics of the Nebraska Sandhills Using Long-Term Measurements and a Hydrology Model

Soil moisture, evapotranspiration, and other major water balance components were investigated for six Nebraska Sandhills locations during a 6 year period (1998–2004) using a hydrological model. Annual precipitation in the study period ranged from 330 to 580?mm. Soil moisture was measured continuously at 10, 25, 50, and 100?cm depth at each site. Model estimates of surface (0–30?cm), subsurface (30–91?cm), and root zone (0–122?cm) soil moisture were generally well correlated with observed soil moisture. The correlations were poorest for the surface layer, where soil moisture values fluctuated sharply, and best for the root zone as a whole. Modeled annual estimates of evapotranspiration and drainage beneath the rooting zone showed large differences between sites and between years. Despite the Sandhills’ relatively homogeneous vegetation and soils, the high spatiotemporal variability of major water balance components suggest an active interaction among various hydrological processes in response to precipitation in this semiarid region.