The C-terminal domains of gammaS-crystallin pair about a distorted twofold axis

The 2-domain gammaS-crystallin, a highly conserved early evolutionary off-shoot of the gamma-crystallin family, is located in the water-rich region of eye lenses. The expressed C-terminal domain, gammaS-C, has been crystallized and the 2.56 A X-ray structure determined. There are two domains in the asymmetric unit which pair about a distorted twofold axis. One of the domains has an altered conformation in a highly conserved region of the protein, the tyrosine corner. The distorted gammaS-C dimer of domains is compared with the highly symmetrical, equivalent recombinant dimer of C-terminal domains from gammaB- crystallin. Sequence changes close to the interface, that distinguish gammaS from the other gamma-crystallins, are examined in order to evaluate their role in symmetrical domain pairing.      

Edible mushroom (Agaricus bisporus) lectin, which reversibly inhibits epithelial cell proliferation, blocks nuclear localization sequence-dependent nuclear protein import

The Galbeta1-3GalNAcalpha (TF antigen)-binding lectin (ABL) from the common edible mushroom (Agaricus bisporus) has a potent anti-proliferative effect without any apparent cytotoxicity. This unusual combination of properties prompted investigation of its mechanism of action. In contrast to soluble lectin, agarose-immobilized, and hence noninternalizable ABL had no effect on proliferation of HT29 colon cancer cells. Electron microscopy of HT29 cells incubated with fluorescein- and gold-conjugated ABL showed internalization of the lectin into endocytotic vesicles and multivesicular bodies. Confocal microscopy showed perinuclear accumulation of fluorescein isothiocyanate-conjugated lectin, which also inhibits HT29 cell proliferation, raising the possibility that the lectin might interfere with nuclear pore function. Transport of heat shock protein 70 into the nucleus in response to heat shock was blocked by preincubation of HT29 cells for 6 h with 40 micrograms/ml ABL. In digitonin-permeabilized cells, nuclear uptake of bovine albumin conjugated to a nuclear localization sequence (NLS)-containing peptide was also inhibited by a 15-min preincubation with 40-100 micrograms/ml ABL. In contrast, serum-stimulated nuclear translocation of mitogen-activated protein kinase, which is NLS-independent, was not affected by pretreatment of cells with the lectin. These results suggest that the anti-proliferative effect of ABL is likely to be a consequence of the lectin trafficking to the nuclear periphery, where it blocks NLS-dependent protein uptake into the nucleus.     

Kalirin inhibition of inducible nitric-oxide synthase

Nitric oxide (NO) acts as a neurotransmitter. However, excess NO produced from neuronal NO synthase (nNOS) or inducible NOS (iNOS) during inflammation of the central nervous system can be neurotoxic, disrupting neurotransmitter and hormone production and killing neurons. A screen of a hippocampal cDNA library showed that a unique region of the iNOS protein interacts with Kalirin, previously identified as an interactor with a secretory granule peptide biosynthetic enzyme. Kalirin associates with iNOS in vitro and in vivo and inhibits iNOS activity by preventing the formation of iNOS homodimers. Expression of exogenous Kalirin in pituitary cells dramatically reduces iNOS inhibition of ACTH secretion. Thus Kalirin may play a neuroprotective role during inflammation of the central nervous system by inhibiting iNOS activity.     

Genitourinary anomalies in the CHARGE association

PURPOSE: We identified the incidence and types of genital and urinary anomalies, and established a plan for evaluating the urinary system in the CHARGE association. MATERIALS AND METHODS: We retrospectively reviewed the charts of 32 patients in whom the CHARGE association was diagnosed. RESULTS: Of the 32 patients identified 22 (69%) had genitourinary abnormalities. Genital anomalies, including micropenis, penile agenesis, hypospadias, chordee, cryptorchidism, a bifid scrotum, atresia of the uterus, cervix and vagina, and hypoplastic labia majora, labia minora and clitoris, were present in 18 patients (56%). Of the 24 patients who underwent renal ultrasound 10 (42%) were diagnosed with urinary tract anomalies including a solitary kidney, hydronephrosis, renal hypoplasia and duplex kidneys. Further evaluation revealed vesicoureteral reflux, neurogenic bladder secondary to spinal dysraphism, nephrolithiasis, ureteropelvic junction obstruction and a nonfunctioning upper pole in both duplex kidneys. CONCLUSIONS: There is a high incidence of genitourinary anomalies in the CHARGE association. Because of this high incidence of anomalies, patients with this condition should undergo a careful genitourinary evaluation, including renal and bladder ultrasound, and voiding cystourethrography screening.     

Organoclays for soil remediation: Adsorption of 2,4-dichlorophenol on organoclay/aquifer material mixtures studied under static and flow conditions

A column material containing organophilic clay particles was developed for soil remediation. 2,4-dichlorophenol adsorption on aquifer material with an effective particle diameter d < 1 mm and various partially modified dioctadecyldimethylammonium–montmorillonite/aquifer material mixtures were studied under static and flow conditions. The 2,4-dichlorophenol adsorption on the aquifer material was negligible. On organoclay/aquifer material mixtures the adsorption capacity increased with increasing organoclay content and the adsorption isotherms could be fitted by the Freundlich equation. In columns filled with organoclay/aquifer material mixtures, the 2,4-dichlorophenol retardation increased with increasing organoclay content up to 1% (w / w). Above 1.5–2.0% (w / w) the permeability of the column material decreased. The HYDRUS_1D model, which solves the convection–dispersion equation for solute transport, was used in a forward and inverse mode to simulate 2,4-dichlorophenol breakthrough in the columns. The simulations revealed that 2,4-dichlorophenol transport exhibited an additional kinetic effect not observed in the batch experiments.     

Modeling the effect of time and temperature on respiration rate of pomegranate arils (cv. "Acco" and "Herskawitz")

Understanding the effect of time and temperature on the respiration rate (RR) of fresh-cut produce, towards the design of a suitable modified atmosphere packaging (MAP) system, requires an adequate mathematical model for prediction of RR as a function of both time and temperature. This study investigated the effect of temperature (5, 10, and 15 °C) and storage time (1 to 5 d) on the RR (R(O2) and R(CO2)) of 2 pomegranate cultivars (cv. "Acco" and "Herskawitz") fresh arils. R(O2) and R(CO2) were 3 to 4 folds significantly higher with increased temperature from 5 to 15 °C and were within the range of 2.51 to 7.59 mL/kg h and 2.72 to 9.01 mL/kg h, respectively, for both cultivars. At 15 °C R(CO2) increased significantly from 8.4 to 25.96 mL/kg h from day 1 to 5, respectively, while at 5 °C R(CO2) changed from 2.9 to 2.05 mL/kg h from day 1 to 5. Temperature had the greatest influence on RR and the interaction of time and temperature also significantly affected R(O2) and R(CO2). The respiratory quotient (RQ) estimated by linear regression was 0.98 at 95% significant level. The dependence of RR on temperature and time was accurately described with a combination of an Arrhenius-type and power equation model for and of fresh pomegranate arils.     

Metabolic transformations of leukotriene B4 in primary cultures of human hepatocytes

Analytic expressions for plasma total titratable base, base excess (DeltaCB), strong-ion difference, change in strong-ion difference (DeltaSID), change in Van Slyke standard bicarbonate (DeltaVSSB), anion gap, and change in anion gap are derived as a function of pH, total buffer ion concentration, and conditional molar equilibrium constants. The behavior of these various parameters under respiratory and metabolic acid-base disturbances for constant and variable buffer ion concentrations is considered. For constant noncarbonate buffer concentrations, DeltaSID = DeltaCB = DeltaVSSB, whereas these equalities no longer hold under changes in noncarbonate buffer concentration. The equivalence is restored if the reference state is changed to include the new buffer concentrations.