Renal cortical blood flow distribution in obstructive nephropathy in rats

To examine the role of intrarenal hemodynamics in in obstructive nephropathy, we determined cortical blood flow distribution (CBFD) in rats with bilateral ureteral occlusion (BUO) and unilateral ureteral occlusion (UUO) during and after release of obstruction. Prior to release of obstruction of 24 hours' duration, we found that outer cortical perfusion decreased by 20+/-5% in both BUO and UUO rats. Furthermore, one hour after release of BUO, there was rapid normalization of CBFD associated with a modest return of glomerular filtration rate (GFR), an almost complete return of renal blood flow (RBF), and a marked postobstructive diuresis. In contrast, after release of UUO, we observed that outer cortical perfusion remained decreased by 21+/-31%, both GFR and RBF remained markedly depressed, and no diuresis occurred. These data demonstrate (1) marked ischemia of the outer cortex in both BUO and UUO during obstruction, (2) a rapid return of CBFD to a normal pattern after release of BUO, but (3) persistent outer cortical ischemia following release of UUO.     

Mitosene-DNA adducts. Characterization of two major DNA monoadducts formed by 1,10-bis(acetoxy)-7-methoxymitosene upon reductive activation

Reductive activation of racemic 1,10-bis(acetoxy)-7-methoxymitosene WV15 in the presence of DNA, followed by enzymatic digestion and HPLC analysis, revealed the formation of various DNA adducts. Reduction is a necessary event for adduct formation to occur. This reductive activation was performed under hypoxic conditions in various ways: (1) chemically, using a 2-fold excess of sodium dithionite (Na2S2O4), (2) enzymatically using NADH-cytochrome c reductase, (3) electrochemically on a mercury pool working electrode, and (4) catalytically, using a H2/PtO2 system. Five different mitosene-DNA adducts were detected. These adducts were also present when poly(dG-dC) was used instead of DNA, but were absent with poly(dA-dT). All were shown to be adducts of guanine. Reduction of 1, 10-dihydroxymitosene WV14 in the presence of DNA did not result in detectable adduct formation, demonstrating the importance of good leaving groups for efficient adduct formation by these mitosenes. Finally, two of the adducts were isolated and their structures elucidated, using mass spectrometry, 1H NMR and circular dichroism (CD). The structures were assigned as the diastereoisomers N2-(1"-n-hydroxymitosen-10"-yl), 2'-deoxyguanosine (n = alpha or beta). These type of adducts, in which the mitosene C-10 is covalently bonded to the N-2 of a guanosylic group, are different from the well-known mitomycin C 2'-deoxyguanosine monoadducts, that is linked via the mitomycin C C-1 position, demonstrating that the order of reactivity of the C-1 and C-10 in these mitosenes is reversed, as compared to mitomycin C. The 7-methoxy substituent of WV15 is a likely factor causing this switch. Evidence is presented that the 7-substituent of mitosenes also influences their DNA alkylation site. Adducts 4 and 5 represent the first isolated and structurally characterized covalent adducts of DNA and a synthetic mitosene.     

The dynamics of prostate specific antigen in hormone refractory prostate carcinoma: an analysis of cancer and leukemia group B study 9181 of megestrol acetate

BACKGROUND: Although many physicians measure serum prostate specific antigen (PSA) during the follow-up of patients with hormone refractory prostate carcinoma (HRPC), little has been done to formalize the determination of how these serial values of PSA impact on prognosis. To understand HRPC fully, make decisions about choices of treatment as well as about clinical research on treatments for HRPC patients, and design appropriate measures of PSA response, it seems that first it would be necessary to understand how these serial measures of PSA relate to survival. The purpose of this study was to determine how repeated measurements of PSA impact on the probability of imminent death for patients with HRPC. METHODS: One hundred forty-eight men with HRPC were enrolled in Cancer and Leukemia Group B Study 9181, in which they were treated with either a low dose (160 mg/day) or a high dose (640 mg/day) of megestrol acetate (MA). Because preliminary data analysis indicated that these treatments had no effect on survival, the authors pooled the data to analyze the overall dynamics of PSA and survival during the follow-up period. The authors attempted to correlate initial and monthly PSA measurements, which were mandated by the study protocol, with the probability of death at any time during follow-up. For statistical analysis, the Cox proportional hazards model and the general linear model were used. In addition to the level of PSA, the authors used the relative velocity of PSA, which was defined as (dy/dt)/y, with "y" symbolizing serum PSA and "t" symbolizing time. RESULTS: Both log(PSA) and the average relative velocity of PSA (rva) were significantly correlated with survival time (P=0.0001 and P=0.0008, respectively), and the analysis performed with the Cox proportional hazards model yielded the following formula for a PSA hazard score: PSA hazard score =0.251*(log(PSA) - mean log(PSA)) + 24.5*(rva - mean rva) This hazard score tended to be higher for patients who were about to die. For example, there was a close correlation between the hazard score and the probability of death as the next observed event. Furthermore, the hazard score provided a dynamic measure of how PSA was affected by treatment. CONCLUSIONS: The average relative velocity of PSA has been identified by the authors as a new measure of the dynamics of PSA in HRPC. It can be determined from sequential values of PSA. This average, together with the log(PSA), are significantly related to the probability of imminent death.     

Hypermobility syndrome. When too much activity causes pain

Hypermobility of joints and spine is a consequence of abnormal laxity of ligaments, joint capsules and intervertebral discs. Hypermobility per se is a state, not a disease. However, it may lead to generalized arthralgia or localized symptoms (frequent ankle sprains, knee effusions, dislocations of the shoulders of recurrent episodes of back pain). These events may occur even after minor strains. Young women are preferentially affected. The term "hypermobility syndrome" is defined as a combination of hypermobility with arthralgia, low back pain, frequent dislocation or sprains. It is often the result of a hereditary disorder of connective tissue. Individuals with hypermobility are at increased risk for premature osteoarthrosis or polytopic disc degeneration of the spine. However, the vast majority of hyperlax individuals are free of symptoms. Those with symptoms who do not develop osteoarthrosis or disc degeneration usually experience spontaneous improvement with increasing age, thus losing their juvenile hyperlaxity. This usually occurs between the ages of thirty and forty. The present review article also provides guidelines for management and patient information.     

Polyurethane rheology modifiers for organic compositions

A need exists for rheological modifiers that provide thickening for organic (oil) phases in the personal care industry. Despite such a significant need, most commercially available oil thickeners have several deficiencies, notably poor efficiency and clarity in formulations. To address this gap, we have developed a novel polyurethane‐based oil thickener (Oil‐Thickener PU) that provides significant thickening (gelation at <1 wt %) and high clarity in a range of natural oils and synthetic emollients. In this work, the structure, thickening mechanism, and viscoelastic properties of neat Oil‐Thickener PU film and Oil‐Thickener in sunflower oil gel are investigated in depth. Results show that the Oil‐Thickener PU provides thickening by forming a physically crosslinked network in oil via hydrogen bonding, resulting in a gel that is shear and temperature sensitive. Given its efficiency and uniqueness, the Oil‐Thickener PU is projected to have use in applications where a thickened organic phase is required. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46372.     

Silsesquioxane Resins as High‐Performance Solution Processible Dielectric Materials for Organic Transistor Applications

Silsesquioxane polymers have been successfully used as the dielectric layer in organic field‐effect transistors (FETs) deposited on robust, plastic substrates. Performance comparable to that found with silicon substrates having SiO₂ as the active dielectric layer was observed with six p‐ and n‐ channel organic semiconductors. These organopolysiloxane materials can be deposited using conventional liquid coating technologies and are compatible with non‐photolithographic microcontact printing. Their low curing temperature permits the use of a variety of low‐cost plastic materials as substrates in FET devices. These findings have facilitated the realization of low‐cost, large area plastic electronics.     

Emergency nurses'' perceptions of critical incidents and stress debriefing

The efficacy of examining antinuclear antibody (ANA) was investigated as a screening test detecting subclinical immune disorders in infertility and sterility. ANA was measured in 116 unexplained infertile or sterile patients. The ANA positive rate was 43.5% in group A (habitual abortion, n = 23), 38.1% in group B (consecutive miscarriages, n = 21), 30.0% in group C (one miscarriage, n = 10), 16.7% in group D (one or more deliveries n = 12) 22.0% in group E (primary sterility, n = 50), and 22.4% in the control group (n = 54). The positive rate for all the infertile patients (group A+B) was 40.9% and significantly higher than that in for the control group (p < 0.05). Ten patients with positive ANA had 12 deliveries and 20 patients with negative ANA had 23 deliveries. The frequency of preeclampsia in the patients with positive ANA was higher than in those with negative ANA (41.7% versus 4.3%, p < 0.05). A higher incidence of premature deliveries was recognized in the patients with positive ANA than in those with negative ANA (41.7% versus 8.7%, p < 0.1). Average birth weight (> 35 week) for patients with and without positive ANA was 2,976g (n = 8) and 3,122g (n = 19) respectively. The former tends to be smaller than the latter (p < 0.1).     

ELECTROCHEMICAL MACHINING OF CURVILINEAR SURFACES

In this work a theoretical analysis of the ECM process of curvilinear surfaces has been presented. The purpose of this analysis is to predict the shape evolution of the machined object using: a shaping surface of small thickness (flat issue) and a blade of hydrodynamic machine (quasi-three dimensional issue). ECM modeling involves prediction of the machined surface shape evolution and distribution of physical-chemical parameters inside the interelectrode gap. The problem has been solved with the use of an equation of the electrolyte and hydrogen mixture (liquid and gas) flat flow inside the interelectrode gap. After introducing simplifying assumptions for the flow, void fraction distribution and the gap thickness, the equations were solved partly analytically, partly numerically. The obtained solutions for assigned parameters of the machining process are presented graphically in the form of distributions of: static pressure, the mixture flow rate, temperature, void fraction and evolution of the machined surface shape evolution.