BRCA carriers after risk-reducing bilateral salpingo-oophorectomy: menopausal hormone therapy knowledge gaps, and the impact of physicians' recommendations.

OBJECTIVE: Female carriers of BRCA1/2 gene mutations are at an increased lifetime risk for breast and ovarian cancers. They are recommended to undergo risk-reducing surgery, including bilateral salpingo-oophorectomy (RR-BSO), upon completion of childbearing. RR-BSO surgery decreases morbidity and mortality but results in early menopause. Menopausal hormone therapy (MHT) is under-utilized despite being shown as safe for carriers. We aim to evaluate the factors associated with decision-making regarding MHT use following RR-BSO in healthy BRCA mutation carriers. METHODS: Female carriers aged <50 years who underwent RR-BSO and were followed in a multidisciplinary clinic completed online multiple-choice and free-text questionnaires. RESULTS: A total of 142 women met the inclusion criteria and filled the questionnaire: 83 were MHT users and 59 were non-users. MHT users underwent RR-BSO earlier than non-users (40.82 ± 3.91 vs. 42.88 ± 4.34; p < 0.0001). MHT usage was positively associated with MHT explanation (odds ratio 4.318, 95% confidence interval [CI] [1.341-13.902], p = 0.014), and knowledge regarding the safety of MHT and its effects on general health (odds ratio 2.001, 95% CI [1.443-2.774], p < 0.0001). MHT users and non-users retrospectively evaluated their comprehension of RR-BSO consequences as significantly lower than before surgery (p < 0.001). CONCLUSION: Post-RR-BSO outcomes, including the effects on women's quality of life and its possible mitigation through MHT use, need to be addressed pre surgery by healthcare providers.

Chitosan as capping agent in a robust one-pot procedure for a magnetic catalyst synthesis.

Here, we report a one-pot solvothermal method for the development of magnetically recoverable catalysts with Ru or Ag nanoparticles (NPs) capped by chitosan (CS), a derivative of natural chitin. The formation of iron oxide NPs was carried out in situ in the presence of CS and iron acetylacetonate in boiling triethyleneglycol (TEG) due to CS solubilization in warm TEG. Coordination with Ru or Ag species and the NP formation take place in the same reaction solution, eliminating intermediate steps. In optimal conditions the method developed allows stabilization of 2.2 nm monodisperse Ru NPs (containing both Ru0 and Ru4+ species) that are evenly distributed through the catalyst, while for Ag NPs, this stabilizing medium is inferior, leading to exceptionally large Ag nanocrystals. Catalytic testing of CS-Ru magnetically recoverable catalysts in the reduction of 4-nitrophenol to 4-aminophenol with excess NaBH4 revealed that the catalyst with 2.2 nm Ru NPs exhibits the highest catalytic activity compared to samples with larger Ru NPs (2.9-3.2 nm). Moreover, this catalyst displayed extraordinary shelf-life in the aqueous solution (up to ten months) and excellent reusability in ten consecutive reactions with easy magnetic separation at each step which were assigned to its conformational rigidity at a constant pH. These characteristics as well as favorable environmental factors of the catalyst fabrication, make it promising for nitroarene reduction.

Facile Synthesis of Magnetically Recoverable Pd and Ru Catalysts for 4-Nitrophenol Reduction: Identifying Key Factors.

This paper reports the development of robust Pd- and Ru-containing magnetically recoverable catalysts in a one-pot procedure using commercially available, branched polyethyleneimine (PEI) as capping and reducing agent. For both catalytic metals, ∼3 nm nanoparticles (NPs) are stabilized in the PEI shell of magnetite NPs, whose aggregation allows for prompt magnetic separation. The catalyst properties were studied in a model reaction of 4-nitrophenol hydrogenation to 4-aminophenol with NaBH4. A similar catalytic NP size allowed us to decouple the NP size impact on the catalytic performance from other parameters and to follow the influence of the catalytic metal type and amount as well as the PEI amount on the catalytic activity. The best catalytic performances, the 1.2 min-1 rate constant and the 433.2 min-1 turnover frequency, are obtained for the Ru-containing catalyst. This is discussed in terms of stability of Ru hydride facilitating the surface-hydrogen transfer and the presence of Ru4+ species on the Ru NP surface facilitating the nitro group adsorption, both leading to an increased catalyst efficiency. High catalytic activity as well as the high stability of the catalyst performance in five consecutive catalytic cycles after magnetic separation makes this catalyst promising for nitroarene hydrogenation reactions.

Acute stimulation of creatine kinase activity by vitamin D metabolites in the developing cerebellum.

There is increasing evidence that vitamin D metabolites have a developmental function. We have investigated the influence of the vitamin D status on the activity of creatine kinase in the brain. Normally fed rats show an increase in the specific activity of cerebral and cerebellar creatine kinase during postnatal development. Vitamin-D-depleted rats failed to show this normal increase. Developing cerebellum, but not cerebrum, in both vitamin D-depleted rats and in normally fed animals, responded sequentially to a single injection of a vitamin D metabolite by displaying increased creatine kinase specific activity. In 5-25-day-old rats, 24R,25-dihydroxyvitamin D-3 significantly increased creatine kinase specific activity 24 h after injection. In contrast, 1,25-dihydroxyvitamin D-3 stimulated cerebellar creatine kinase activity from 20 days after birth. A similar pattern of sequential responsiveness to vitamin D metabolites, but at an earlier age, was shown in the cerebellum of the rabbit, which is a 'perinatal brain developer' compared to the rat, a 'postnatal brain developer'. Because of the difficulty in obtaining vitamin D-depleted rabbits, studies were carried out in normally fed animals. In these rabbits, 24R,25-dihydroxyvitamin D-3 stimulated cerebellar creatine kinase activity between 6 days before birth and 9 days after birth, while 1,25-dihydroxyvitamin D-3 caused an increase in cerebellar creatine kinase specific activity from 8 days after birth. These developmental differences found in creatine kinase basal activity and responsiveness are correlated with differences in cellular growth rates, both in the rabbit and in the rat, suggesting that vitamin D metabolites may be required for optimal cerebellar development.

Autoimmune thrombocytopenia: flow cytometric determination of platelet-associated autoantibodies against platelet-specific receptors.

Immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by antibody-induced platelet destruction. Despite its clinical importance, the diagnosis of ITP is one of exclusion, thus, inevitably associated with potential difficulties. We here describe a feasible diagnostic method using the commonly available technique of flow cytometry. An antigen-specific assay for platelet-associated antibody was developed and tested in 62 adult patients with chronic ITP, 14 patients with thrombocytopenia of decreased production and 60 healthy controls. The method is based on flow cytometric (FCM) detection of autoantibodies reacting with specific platelet receptors immobilized on microbeads. The average fluorescence level in the ITP group calculated as a ratio to normal was 4.07 (range 0.8-31.0), in the non-ITP thrombocytopenic patients 0.9 (range 0.7-1.2), and in the healthy controls 1.0 (range 0.7-1.3). The average assay coefficient of variation was 0.218 [95% confidence interval (CI) 0.213, 0.221]. The difference between the ITP patients and both groups was highly significant (P < 0.001), using a stringent non-parametric analysis. A comparison of the FCM assay with the radioactive immunobead assay previously reported on the same cohort of patients showed significant correlation (R2 = 0.71, 95% CI 0.39, 0.53). The overall performance of the FCM assay in discriminating between ITP patients and normals was estimated by the receiver operating characteristic (ROC) plot, showing an area under the curve of 0.96 (maximal value 1.0), with standard error of 0.033. We conclude that the present FCM assay is clinically useful for routine diagnosis and follow-up of ITP.

A minimized M13 coat protein defines the requirements for assembly into the bacteriophage particle.

The M13 filamentous bacteriophage coat is a symmetric array of several thousand alpha-helical major coat proteins (P8) that surround the DNA core. P8 molecules initially reside in the host membrane and subsequently transition into their role as coat proteins during the phage assembly process. A comprehensive mutational analysis of the 50-residue P8 sequence revealed that only a small subset of the side-chains were necessary for efficient incorporation into a wild-type (wt) coat. In the three-dimensional structure of P8, these side-chains cluster into three functional epitopes: a hydrophobic epitope located near the N terminus and two epitopes (one hydrophobic and the other basic) located near the C terminus on opposite faces of the helix. The results support a model for assembly in which the incorporation of P8 is mediated by intermolecular interactions involving these functional epitopes. In this model, the N-terminal hydrophobic epitope docks with P8 molecules already assembled into the phage particle in the periplasm, and the basic epitope interacts with the acidic DNA backbone in the cytoplasm. These interactions could facilitate the transition of P8 from the membrane into the assembling phage, and the incorporation of a single P8 would be completed by the docking of additional P8 molecules with the second hydrophobic epitope at the C terminus. We constructed a minimized P8 that contained only nine non-Ala side-chains yet retained all three functional epitopes. The minimized P8 assembled into the wt coat almost as efficiently as wt P8, thus defining the minimum requirements for protein incorporation into the filamentous phage coat. The results suggest possible mechanisms of natural viral evolution and establish guidelines for the artificial evolution of improved coat proteins for phage display technology.

Comprehensive mutagenesis of the C-terminal domain of the M13 gene-3 minor coat protein: the requirements for assembly into the bacteriophage particle.

Filamentous bacteriophage assemble at the host membrane in a non-lytic process; the gene-3 minor coat protein (P3) is required for release from the membrane and subsequently, for recognition and infection of a new host. P3 contains at least three distinct domains: two N-terminal domains that mediate host recognition and infection, and a C-terminal domain (P3-C) that is required for release from the host cell following phage assembly and contributes to the structural stability of the phage particle. A comprehensive mutational analysis of the 150 residue P3-C revealed that only 24 side-chains, located within the last 70 residues of sequence, were necessary for efficient incorporation into a wild-type coat. The results reveal that the requirements for the assembly of P3 into the phage particle are quite lax and involve only a few key side-chains. These findings shed light on the functional and structural requirements for filamentous phage assembly, and they may provide guidelines for the engineering of improved coat proteins as scaffolds for phage display technology.

Effects of recombinant human granulocyte-macrophage colony-stimulating factor on platelet survival and activation using a nonhuman primate model.

In humans and nonhuman primates, the in vivo administration of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) consistently results in marked increase of megakaryocyte ploidy and size similar to that observed with interleukin-6 (IL-6). However, whereas the administration of IL-6 also results in an increase in circulating platelets, there is no predictable corresponding increase in peripheral blood platelets following treatment with rhGM-CSF. To determine whether the failure of rhGM-CSF to produce thrombocytosis is secondary to cytokine-related increased platelet activation and consumption in vivo, we quantified autologous platelet survival time and in vivo platelet activation before and during 5 days of administration of rhGM-CSF to two rhesus monkeys. Platelet survival was measured using autologous platelets labeled with 111Indium-oxine. Platelet activation was assessed by flow cytometric determination of the expression of the major platelet membrane glycoprotein (GP) IIb/IIIa complex, and an activation-dependent epitope on GPIIb/IIIa (recognized by monoclonal antibodies [MABs] LJ-P4 and PAC1, respectively). Platelet activation was also assessed by dose-response aggregometry using adenosine diphosphate (ADP). While megakaryocyte ploidy increased during rhGM-CSF administration, peripheral platelet counts were 418 x 10(9)/L and 525 x 10(9)/L before and 402 x 10(9)/L and 508 x 10(9)/L during cytokine treatment in animals 1 and 2, respectively. No changes were observed in the mean platelet volume. 111Indium-labeled platelet recovery in circulation was similar before (94.7%, 91.8%) and during (92.9%, 92.8%) rhGM-CSF administration, which indicates that cytokine-related in vivo sequestration of platelets does not occur. Autologous platelet survival was 5.6 and 6.2 days before and 5.0 and 5.4 days during the rhGM-CSF treatment (p = 0.07), without significant change in the corresponding platelet turnover rate (derived from the platelet count and survival time). The flow cytometric analysis showed no increase in the binding of either LJ-P4 or PAC1 MABs to the platelet membrane during rhGM-CSF administration. The aggregometry studies demonstrated similar concentrations of ADP inducing half-maximal aggregation (ED50). Overall, the above data indicate that treatment with rhGM-CSF is not associated with in vivo activation, sequestration, or increased consumption of platelets. The data suggest that the failure of rhGM-CSF-stimulated megakaryocytes to increase peripheral platelet count is a manifestation of ineffective megakaryocytopoiesis resulting from inability to increase platelet delivery to the circulation.

Exaggerated platelet reactivity in major depression.

OBJECTIVE: This study investigated whether depressed patients exhibit exaggerated platelet reactivity. METHOD: In vivo platelet activation, secretion, and dose-response aggregation were measured in 12 depressed patients and eight normal comparison subjects after overnight bed rest and following orthostatic challenge. RESULTS: The depressed patients exhibited increased platelet activation at baseline, demonstrated by increased binding of monoclonal antibody (moAb) annexin V protein reacting with prothrombinase complex binding sites. Following orthostatic challenge, the depressed patients exhibited increases in binding of moAbs PAC1 and anti-LIBS1 against activated glycoprotein IIb/IIIa and GE12 against P-selectin expressed upon secretion. The normal comparison subjects exhibited increases in platelet activation only with GE12. CONCLUSIONS: Depressed patients exhibit enhanced baseline platelet activation and responsiveness in comparison with normal subjects. Heightened susceptibility to platelet activation may be a mechanism by which depression is a significant risk factor for ischemic heart and cerebrovascular disease and/or mortality after myocardial infarction.

Reduction of pain episodes and prothrombotic activity in sickle cell disease by dietary n-3 fatty acids.

The effects of dietary n-3 fatty acids (n-3FAs) on the frequency of pain episodes and ex vivo blood tests of thrombosis have been evaluated in patients with sickle cell disease (SCD) utilizing a double-blind, olive oil-controlled clinical trial. Dietary n-3FA therapy (0.1 g/kg/d) was provided as menhaden fish oil (0.25 g/kg/d) containing 12% eicosapentaenoic acid (EPA), and 18% docosahexaenoic acid (DHA). Within 1 month dietary n-3FAs exchanged with n-6FAs in plasma and erythrocyte membrane phospholipids (p <0.01 in all cases). Treatment with dietary n-3FAs for 1 year reduced the frequency of pain episodes requiring presentation to the hospital from 7.8 events during the preceding year to 3.8 events/year (p <0.01; n = 5). By contrast, subjects receiving control dietary olive oil (n = 5) experienced 7.1 pain events/year, compared to 7.6 during the previous year (p >0.4). The reduction in episodes in n-3FA-treated subjects was also significant when compared to control subjects (p <0.01). Dietary n-3FA therapy was not associated with hemorrhagic, gastrointestinal or other adverse effects. Compared to 10 asymptomatic African-American controls, sickle cell subjects demonstrated significantly increased pretreatment: 1) flow cytometric expression of platelet membrane P-selectin (CD62p; p <0.01) and annexin V binding sites (p = 0.02); 2) plasma levels of platelet-specific secretory proteins platelet factor 4 (PF4) and beta-thromboglobulin (betaTG) (p <0.01 in both cases); 3) plasma products of thrombin generation, prothrombin fragment 1.2 (F1.2) and thrombin:antithrombin (TAT) complex (p <0.01 in both cases); and 4) plasma levels of thrombolytic products, D-dimer and plasmin:antiplasmin (PAP) complex (p <0.01 in both cases). Treatment with dietary n-3FAs concurrently decreased plasma levels of F1.2, D-dimer, and PAP (p <0.05, compared to olive oil controls), implying that the reduction in pain events was related to n-3FA-dependent inhibition of thrombosis. We conclude that dietary n-3FAs reduce the frequency of pain episodes perhaps by reducing prothrombotic activity in sickle cell disease.

Ischemia stress and arachidonic acid metabolites in the fetal brain.

Hypoxic-ischemic insults caused by placental insufficiency in perinatal life are today considered a major cause for neuronal injury and impaired postnatal development. A major consequence of placental insufficiency and ischemia is the change in metabolism of arachidonic acid and its oxidation products. A burst of postischemic production of prostaglandins, unequivocally shown in many systems, is documented in the fetal rabbit brain as well as in placenta tissue soon after vascular restriction. PGE2, a most abundant prostaglandin of the fetal brain, is particularly elevated. Similarly, thromboxane B2 and 6-keto PGF1 alpha, the stable metabolites of thromboxane A2 and prostacyclin, are both increased over the control values. However, after 48 h of restriction, the levels of these eicosanoids are restored to near-normal values. The metabolic machinery responsible for the conversion of arachidonic acid into eicosanoids in brain and placenta tissues appears to be impaired following a period of placental insufficiency. This inhibition can be accounted for by excessive production of eicosanoids and also by formation of an endogenous inhibitor or free radicals. Studies are in progress to test these possibilities.

Adherence in childhood diabetes: results of a confirmatory factor analysis.

In an earlier study (Johnson, Silverstein, Rosenbloom, Carter, & Cunningham, 1986), an exploratory factor analysis identified five components of adherence in childhood diabetes. In this investigation, a simultaneous confirmatory analysis was used to test the equality of this factor pattern across two independent samples. Factors 1 through 4--Exercise, Injection, Diet Type, and Eating/Testing Frequency-were confirmed. Factor 5--Diet Amount--proved to be too complex; the adherence measures comprising this factor (total calories and concentrated sweets consumed) are best treated as separate, single-indicator constructs. The results support a multivariate conceptualization of adherence, offer insight into the nature of the components underlying diabetes adherence, and provide measurement information for reliable component estimation.

Dosimetric problems at low monitor unit settings for scanned and scattering foil electron beams.

Electron beam dosimetry at low monitor unit (MU) settings is important for dosimetric applications. Dose linearity, beam flatness, and beam energies were studied at low MU settings with various dose rates for different types of linear accelerators. It is observed that for the scattering foil units, the dose/MU is a smooth function of MU for all beam energies. Discrepancies in dose/MU are highest at the lowest MU. Significant variation (5%-245%) in dose linearity is observed among various linear accelerators at low MU settings. Dose rate has no effect on the dose linearity for all energies for the scattering foil units tested. On the contrary, for the scanned beam, there is no predictable pattern as dose/MU is random in nature and varies with time and beam energy. The maximum dosimetric error is observed for the highest energy beam where the beam width is most narrow. Using film, the beam uniformity was noticed to be very poor at low MU and high energy for scanned beams. The beam uniformity and dose linearity are random at low MU due to the random nature of the scan cycle. Under the adverse conditions, the deviation in dosimetric parameters was observed up to 200 MU.

Structure of everyday memory in adults with Age-Associated Memory Impairment.

Everyday memory was tested in a group of adults manifesting Age-Associated Memory Impairment; a computerized battery of tests was constructed to simulate memory tasks of daily life. Confirmatory and other structural equation models were estimated for the entire sample of 273 Ss and for 3 age groups. A 4-factor model was found to fit the data well and was invariant across age and gender. After education had been controlled, only the General Recall factor was found to be consistently related to age in both men and women; the other 3 factors--Narrative Memory, Digit Recall, and Visual Memory--were related to age only in men. Confirmatory factor analyses of the everyday memory tests combined with several psychometric memory tests suggested that some of the latter (the Benton Visual Retention Test and Wechsler Memory Scale Hard Paired Associates) load on more than 1 factor of everyday memory, suggesting complex relationships between the 2 types of tests.

Reporting structural equation modeling results in Psychology and Aging: some proposed guidelines.

Structural equation modeling (SEM) is now widely used in social and behavioral science research. SEM provides the possibility of fitting, and evaluating the fit, of well-specified, theoretical models to empirical data--more generally, of testing elaborated psychological theories. The options available to users of these approaches are many and varied. Popular SEM computational software packages, such as LISREL and EQS, provide a large amount of information, and there is some uncertainty as to what should be routinely reported. A series of guidelines are proposed for reporting SEM results in articles submitted to Psychology and Aging. The suggested guidelines ask authors using SEM methodology to provide important analysis information that will enable readers to evaluate the findings.

Platelet activation as a marker for in vivo prothrombotic activity: detection by flow cytometry.

Circulating platelets play a pivotal role in hemostasis. The platelet hemostatic function involves the direct interaction with damaged vessel walls, and circulating coagulation factors, primarily thrombin resulting in platelet activation, aggregation and formation of hemostatic plug. Flow cytometry is a useful technique for the study of platelet activation in circulating blood. Platelet activation markers for ex vivo analysis may include a) activation-dependent epitopes of the membrane glycoprotein (GP) IIb/IIIa (CD41a) receptor, as demonstrated by the binding of activation-specific monoclonal antibodies (MoAbs) PAC1, anti-LIBS1 and anti-RIBS); b) the expression of P-selectin (CD62p), the alpha-granule GP translocated to the platelet surface following release reaction; and c) platelet procoagulant activity, as demonstrated by the binding of i) annexin V protein to the prothrombinase-complex (prothrombin, activated factor X (Xa) and V (Va)) binding sites on the surface of activated platelets, and of ii) MoAbs against activated coagulation factors V and X bound to the surface of activated platelets. Using this method, platelet activation as a marker for in vivo prothrombotic activity can be demonstrated in various clinical conditions including coronary angioplasty, orthostatic challenge in primary depression, sickle cell disease in clinical remission and during pain episode, and in pregnancy-related hypertension with marked increase during preeclampsia. The finding of platelet procoagulant activity is corroborated by increased levels of plasma markers for thrombin generation and fibrinolytic activity.

Neurodevelopmental outcome in children with intrauterine growth retardation: a 3-year follow-up.

The study was designed to detect early clinical predictors of developmental outcome in children with intrauterine growth retardation. Eighty-five children with intrauterine growth retardation were followed up prospectively to 3 years of age, using biometric parameters, perinatal risk questionnaires, and neurodevelopmental evaluations. Forty-two children served as controls. A significant difference in neurodevelopmental score at 3 years of age was noted between the intrauterine growth retardation and control groups (P < .001). In the intrauterine growth retardation group, the clinical parameters that most significantly correlated with outcome were cephalization index (head circumference:birthweight ratio), neonatal risk score, and birthweight. The best predictor of 3-year outcome was the cephalization index (P < .01). The children with intrauterine growth retardation with neonatal complications had significantly lower IQ scores (P < .05) and a poorer neurodevelopmental outcome (P < .01) than those without complications. Children with intrauterine growth retardation are at higher risk for developmental disabilities than are controls, especially in the presence of neonatal complications and a high cephalization index.

Increased coagulation factor levels leading to allograft renal vein thrombosis.

A patient with end-stage kidney disease is described, who lost his renal allograft in the early post-transplant period due to allograft renal vein thrombosis. Prior to transplantation, he had been treated by hemodialysis and lost several vascular accesses because of thrombosis. A search for potential thrombophilic factors disclosed a unique combination of increased clotting factor levels, i.e. FVIII, FIX, FXI and homocysteine. More common hereditary and acquired hypercoagulability factors have been excluded in this patient. While clotting factor deficiencies are well known causes of hemophilia, their levels should also be measured in the workup of transplant candidates with a history of multiple vascular access thrombosis.

Brain: body ratio and conceptional age in vascular-induced intrauterine growth retarded rabbits.

Vascular induced intrauterine growth retardation (IUGR) was achieved by total ligation of approximately 30% of the placental vessels to half the fetuses in the last third of gestation in pregnant rabbits. A correlation between brain weight, body weight and head circumference was established in fetuses and rabbit pups in the perinatal period. The brain:body ratio in restricted IUGR animals was significantly higher than their homologous normal controls. A cephalization index based on the brain:body ratio is proposed to assess adverse effects on brain maturity in the presence of IUGR induced by placental insufficiency.

The cephalization index: a screening device for brain maturity and vulnerability in normal and intrauterine growth retarded newborns.

Predictive estimates of future neurological maldevelopment as a result of vascular induced intrauterine injury are based on the assumption that the body is more affected than the brain resulting in asymmetrical intrauterine growth retarded (IUGR) newborns. The higher the brain:body ratio, the more severe the IUGR process and the greater the risk for the brain to be affected. This prompted us to study in human newborns, a cephalization index based on the ratio of head circumference to body weight to express the degree of brain maturity and possible vulnerability in relation to gestational age. The newborn cephalization index was correlated with neurodevelopment. A trend could be delineated; in the later gestational age, the higher the cephalization index reflecting a greater degree of brain vulnerability, the more severe the clinical pathology; especially the likelihood of cerebral palsy and severe psychomotor retardation. The cephalization index may serve as an additional screening device for high risk intrauterine growth retarded newborns.