Q2 evolution of the generalized Gerasimov-Drell-Hearn integral for the neutron using a 3He target

We present data on the inclusive scattering of polarized electrons from a polarized 3He target at energies from 0.862 to 5.06 GeV, obtained at a scattering angle of 15.5 degrees. Our data include measurements from the quasielastic peak, through the nucleon resonance region, and beyond, and were used to determine the virtual photon cross-section difference sigma(1/2)-sigma(3/2). We extract the extended Gerasimov-Drell-Hearn integral for the neutron in the range of four-momentum transfer squared Q2 of 0.1-0.9 GeV2.

Hydroxyapatite/calcium carbonate (HA/CC) vs. plaster of Paris: a histomorphometric and radiographic study in a rabbit tibial defect model

The search for an ideal bone substitute is ongoing. Multiple osteoconductive bone substitutes are available today. Plaster of Paris (POP) (calcium sulfate) has been used for more than 100 years for treatment of skeletal defects. This implant is compared to a new material, hydroxyapatite/calcium carbonate (HA/CC), in a rabbit tibia model. HA/CC is made from partial conversion of coralline calcium carbonate to hydroxyapatite and has an outer hydroxyapatite layer and an inner calcium carbonate core, a combination that leads to faster resorption than that of pure hydroxyapatite. This study compares the histomorphometric and radiographic properties of POP and HA/CC in a rabbit tibial defect. Both implants preferentially restore bone to the cortex relative to the canal. Plaster of Paris was fully resorbed by 6 weeks both radiographically and histometrically and HA/CC was substantially resorbed by 42 weeks. No significant difference was noted in volume fraction of bone between the two implants at 42 weeks postimplantation. Hydroxyapatite/calcium carbonate is a biocompatible bone graft substitute with a rate of resorption significantly slower than plaster of Paris.

Precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e, e')

We present the first precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e,e') at Q2 values of 0.1 and 0.2 (GeV/c)2. The agreement between the data and nonrelativistic Faddeev calculations which include both final-state interactions and meson-exchange current effects is very good at Q2 = 0.1 (GeV/c)2, while a small discrepancy at Q2 = 0.2 (GeV/c)2 is observed.

Dynamics of the 16O(e, e'p) reaction at high missing energies

We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25<E(m)<50 MeV and P(m) approximately 60 MeV/c, the reaction is dominated by a single 1s(1/2) proton knockout. At larger P(m), the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.

Application of the National Cancer Institute international criteria for determination of microsatellite instability in ovarian cancer

Recently, the National Cancer Institute (NCI) established criteria for determination of microsatellite instability (MSI) in colorectal tumors. Although the best panel of markers for ovarian tumors is not known, we evaluated epithelial ovarian cancers for MSI based on the NCI recommendations. One hundred and nine ovarian tumors were analyzed for MSI by gel analysis of paired germ-line and tumor DNA. PCR amplification was performed using the panel of five microsatellite markers recommended by the NCI (BAT25, BAT26, D5S346, D2S123, and D17S250) and nine additional markers picked based on their genomic location (NME1, D10S197, D11S904, D13S175, DXS981, DXS6800, DXS6807, AR, and D3S1611). Tumors were characterized on the basis of: high-frequency MSI (MSI-H) if two or more of the five NCI markers showed instability or there was instability at 30% or more of all markers tested; or low-frequency MSI (MSI-L) if only one of the five NCI markers showed instability or <30% of all of the markers. All of the other tumors were considered microsatellite stable. On the basis of the NCI markers, 12 (11%) tumors demonstrated MSI-H, and 8 (7%) additional tumors had MSI-L. When all of the 14 markers were considered together, 13 (12%) tumors demonstrated MSI-H (based on 30% or more unstable loci), and 26 (24%) tumors had MSI-L. A single tumor identified to have MSI-H based upon all of the markers tested would have been classified as MSI-L based upon the NCI markers alone. Inclusion of an additional dinucleotide marker (NME1) to the NCI panel allowed detection of all of the tumors with MSI-H using only six markers. MSI-H occurs in approximately 12% of invasive ovarian tumors. For optimal detection of microsatellite instability in ovarian cancer, an additional marker (NME1) may be required, along with the five recommended by the NCI.

Interaction of glutathione S-transferase M1 and T1 genotypes and malignant melanoma

The mu and theta classes of glutathione S-transferases (GST) may affect the development of cutaneous malignant melanoma (CMM) by decreasing cellular oxidative stress in skin. These isozymes are absent in a large proportion of the population because of germ-line homozygous deletions in the genes encoding GSTM1 and GSTT1. To determine the association between GSTM1 and GSTT1 homozygous deletions (GSTM1 null and GSTT1 null, respectively) and CMM, we studied 212 patients with CMM, 150 patients with CMM and dysplastic nevi (DN), 147 patients with DN alone, and 124 healthy persons without CMM or DN. Comparing CMM cases (n = 362) to participants without CMM (n = 271), we found no association with GSTM1 null [odds ratio (OR), 1.2; 95% confidence interval (CI), 0.86-1.6] or GSTT1 null (OR, 0.82; 95% CI, 0.56-1.2), either independently or in combination (OR, 1.4; 95% CI, 0.81-2.2), after adjusting for age. However, among the subset of participants with red or blond hair, those with CMM were twice as likely to carry GSTM1 null (OR, 2.2; 95% CI, 1.2-4.2) and nearly 10-fold more likely to carry both GSTM1 null and GSTT1 null (OR, 9.5; 95% CI, 1.2-73) compared with those without CMM. These data suggest that among persons with hair colors traditionally associated with increased risk for melanoma, absence of both GSTM1 and GSTT1 may act to further elevate CMM risk.

Transverse asymmetry AT' from the quasielastic 3He(e,e') process and the neutron magnetic form factor

We have measured the transverse asymmetry A(T') in 3He(e,e(')) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q2 values from 0.1 to 0.6 (GeV/c)(2). The neutron magnetic form factor G(n)(M) was extracted based on Faddeev calculations for Q2 = 0.1 and 0.2 (GeV/c)(2) with an experimental uncertainty of less than 2%.

An immunohistochemical study of type I insulin-like growth factor receptors in the placentae of pregnancies with appropriately grown or growth restricted fetuses

Insulin-like growth factors (IGFs) and their receptors in the fetus are essential for growth and postnatal survival but the role of maternal IGFs is less well understood. Animal and in vitro evidence suggests that maternal IGF-I may have important effects on placental function. Recent work in humans suggests that although there is no relationship between maternal serum IGF-I and normal fetal growth, levels are low in pregnancies complicated by fetal growth restriction due to placental dysfunction. A prospective and observational study was undertaken of the distribution and concentration of placental type I IGF receptors (IGF-IR) in women with small for gestational age (n=26) or appropriately grown (n=14) fetuses. Women were scanned biweekly from 24 weeks to delivery and cases (birthweight <5th centile) were assigned to two groups: 'fetal growth restriction' (FGR; umbilical artery pulsatility index [UAPI] > +2 s.d.; n=16) and 'normal small for gestational age' (SGA; normal UAPI, growth velocity and amniotic fluid; n=10). Immunohistochemistry of the IGF-IR was performed on formol saline-fixed placental biopsies obtained at delivery. In control pregnancies IGF-IR were present in villous endothelium and stroma, trophoblast and decidua and their distribution and density were unchanged in both SGA and FGR pregnancies. We hypothesize that a therapeutic elevation of maternal IGF-I in FGR pregnancy might lead to enhanced placental function and so fetal growth. Our findings of normal localization and density of placental IGF-IR in FGR encourage us to extend our work to look at the effects of maternal IGF-I on the transport of glucose and amino acids.

Evaluating the impact of workstation usage on radiology report times in the initial 6 months following installation

Picture archiving and communications systems (PACS) workstations are reported to improve workflow by making studies immediately available for review upon their completion. This study tested the hypothesis that a workstation would decrease the time from completion of a study to dictation of results (report time). A four-monitor, 2K x 2K workstation (Imation Cemax-Icon, Fremont, CA), was installed in a body imaging computed tomography (CT) reading room. Use of the workstation by the staff radiologists was voluntary. Images were also printed on film and films continued to be hung at the routine hanging times. To evaluate the workstation's maximum impact, data were collected for report times for studies completed during the routine day shift of the staff radiologist (Monday to Friday, 8 AM to 5 PM). Data were collected before workstation installation (August 1997 to November 1997) and for the subsequent 6 months. Histograms of the number of studies (743 v 103) versus report time (mean, 11.7 v 7.4 hours) showed a bimodal distribution, with peaks at approximately 6 and 24 hours, both before (8/97-11/97) and after (6/98) the workstation's installation. However, the number of studies dictated greater than 60 hours (25.2% v 20.4%) and the percentage of studies in the second peak (16 to 48 hours; 4.4% v 0%) both decreased. In conclusion, the workstation decreased the mean (11.7 v 7.4 hours) and standard deviation (19.8 v 9.1 hours) for report times. This was due to a decrease in both the number of cases dictated the day following their completion and the number of outliers (markedly delayed dictations). The decrease in outliers is probably due to a decrease in the number of "lost" film-based studies.

NH2-terminally truncated HER-2/neu protein: relationship with shedding of the extracellular domain and with prognostic factors in breast cancer

We identified an NH2-terminally truncated HER-2/neu product of M(r) 95,000 with in vitro kinase activity by Western blotting and immunoprecipitations using domain-specific antibodies. p95 levels correlated with the extracellular domain (ECD) shed from different cells under varied conditions. Both ECD and p95 were at approximately 20-fold lower levels in SKOV3 ovarian carcinoma cells, as compared to BT474 breast carcinoma cells. Both were stimulated by treatment of cells with the phorbol ester tumor promoter phorbol 12-myristate 13-acetate and the lysosomotrophic agent chloroquine. The hydroxamate inhibitor of metalloproteases, TAPI, suppressed both p95 and ECD in a dose-dependent fashion, with maximal inhibition at < or = 10 microM in BT474 cells. Cancer tissues were analyzed by Western blotting and scored for p95HER-2/neu and for p185HER-2/neu expression. Breast and ovarian cancer tissues were both found to express p95HER-2/neu in addition to p185HER-2/neu. Of 161 breast cancer tissues, 22.4% expressed p95, 21.7% overexpressed p185, and 14.3% were p95 positive and overexpressed p185. A higher proportion of node-positive patients (23 of 78) than node-negative patients (9 of 63) expressed p95 in all tumors combined (P = 0.032). In the group that overexpressed p185, those that contained p95 were associated with node-positive patients (15 of 21), whereas those that were p95 negative were associated with node-negative patients (8 of 11; P = 0.017). Neither p95- nor p185-rich patients significantly correlated with tumor size or with hormone receptor status in this study. Our findings show that breast cancers, which express the HER-2/neu oncogene, are heterogeneous with respect to HER-2/neu protein products. p95HER-2/neu appears to distinguish tumors that have metastasized to the lymph nodes from those in node-negative patients.

Human ocular aldehyde dehydrogenase isozymes: distribution and properties as major soluble proteins in cornea and lens

Human aldehyde dehydrogenase isozymes (ALDHs; EC 1.2.1.3) exhibit very high levels of activity in anterior eye tissues. Human corneal ALDH1 and ALDH3 isozymes are present as major soluble proteins (3% and 5%, respectively, of corneal soluble protein) and may play major roles in protecting the cornea against ultraviolet radiation (UVR)-induced tissue damage, as well as contributing directly to ultraviolet B (UV-B) photoreception. The human lens exhibits high levels of ALDH1 activity (1-2% of lens-soluble protein) and lower levels of ALDH3 activity. Kinetic analyses support a role for these enzymes in the metabolism of peroxidic aldehydes, which have been reported in ocular tissues.

Prognosis following prenatal diagnosis of heart malformations

Our objective was to document the prognosis of cases with fetal heart malformations (FHM). Forty-two fetuses assessed both in a regional fetal medicine and paediatric cardiology unit were classified prenatally into isolated FHM or those associated with extra-cardiac structural or karyotypic anomalies (ECA) and this classification was not changed subsequently (analogous to an intention to treat analysis). The end points studied included chromosomal abnormality, pregnancy outcome and follow-up at one year of age. FHM were isolated in 16 (38%) and associated with ECA in 26 (62%) of cases. The karyotypic abnormality rate was 8/42 (19%) overall and 8/26 (31%) in ECA cases. The pregnancy outcome included termination of pregnancy in 19 (45%), intrauterine death of two (5%) and live birth in 21 (50%). 12/16 (75%) of isolated FHM cases were live born compared with 9/26 (35%) of ECA cases (P < 0.03). Of the isolated FHM live born babies, 8/12 (67%) were alive at the end of the first year and seven of these were growing normally and did not require cardiac medication. However, a considerable proportion of their first year was spent in hospital (median 8%, interquartile range 5-10). Only one of nine ECA live born cases was alive but with poor growth and dependence on cardiac drugs at one year. These data confirm previous findings in prenatal diagnosis series that the prognosis for FHM is worse than that reported in studies of congenital heart disease at birth and is strongly dependent upon the presence of ECA. In their absence, outcome is better than previously published. Counselling must take place only after full fetal medicine assessment and should be based upon prenatal data.