Collective chain dynamics in lipid bilayers by inelastic x-ray scattering

We investigated the application of inelastic x-ray scattering (IXS) to lipid bilayers. This technique directly measures the dynamic structure factor S(q,omega) which is the space-time Fourier transform of the electron density correlation function of the measured system. For a multiatomic system, the analysis of S(q,omega) is usually complicated. But for multiple bilayers of lipid, S(q,omega) is dominated by chain-chain correlations within individual bilayers. Thus IXS provides a unique probe for the collective dynamics of lipid chains in a bilayer that cannot be obtained by any other method. IXS of dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylcholine + cholesterol at two different concentrations were measured. S(q,omega) was analyzed by three-mode hydrodynamic equations, including a thermal diffusive mode and two propagating acoustic modes. We obtained the dispersion curves for the phonons that represent the collective in-plane excitations of lipid chains. The effect of cholesterol on chain dynamics was detected. Our analysis shows the importance of having a high instrument resolution as well as the requirement of sufficient signal-to-noise ratio to obtain meaningful results from such an IXS experiment. The requirement on signal-to-noise also applies to molecular dynamics simulations.     

Effects of zinc supplementation to ration on some hematological parameters in broiler chicks

The aim of the study was to examine the effects of zinc supplementation on some hematological parameters. Sixty newborn male broiler chicks were utilized in the study. Zinc (Zn) was added into drinking water at levels of 0, 125, 500, and 1000 mg/kg. In the study, there was no significant difference between control and Zn-supplemented groups in erythrocyte count, hemoglobin amount, hematocrit levels, total leukocyte count, and differential leukocyte % levels, but the α-naphthyl acetate esterase ANAE(+) lymphocyte rate significantly (p<0.05) increased in the 125-ppm Zn-supplemented group compared with the control group. In conclusion, the data obtained may be beneficial in demonstrating the effects of zinc on, at least, these parameters.     

Evaluation of the immune response to hepatitis B vaccination in children aged 1-3 years in Malatya, Turkey

By the end of 1998, Turkey had launched the routine vaccination of infants against hepatitis B. The purpose of the study is to evaluate the immune response in a sample of vaccinated children aged 1-3 years in the city of Malatya. A total of 210 vaccinated children 12 to 48 months old were selected for the study with 30 cluster sampling in the city of Malatya, Turkey. The children were visited at their homes during January-April 2002. The information on demographic characteristics, family's and child's medical history was gathered, childrens' weight and height were measured and blood samples were taken. Anti-HBs, HbsAg and anti-HBc titers were assayed by micro-ELIZA from the sera. The mean age of the children was 26.3 months, 100 (47.6%) were male and 110 (52.4%) were female. Overall, 203 (96.7%) children had protective anti-HBs levels (> or = 10 IU/l), 0.5% showed evidence of natural infection (with positive anti-HBc and anti-HBs titers), 0.5% had acute or chronic infection (with positive HbsAg and anti-HBc titers) and 2.3% were seronegative. Geometric mean titer of anti-HBs among vaccinated children except those who had positive anti-HBc titers was 138.7 mIU/ml (95% CI:124.7-154.2) and seroconversion rates did not differ by age, sex, anthropometric measurements, time after third dose and place of vaccine administered (P > 0.05). The high seroprotection rate over 95% showed that routine infant vaccination program for hepatitis B was successfully carried out in the city Malatya.     

Anti-inflammatory effects of leptin and cholecystokinin on acetic acid-induced colitis in rats: role of capsaicin-sensitive vagal afferent fibers

Leptin and cholecystokinin (CCK) have a synergistic interaction in the suppression of food intake, and afford similar gastroprotective activity. The present study was designed to investigate the putative protective effects of CCK and leptin on acute colonic inflammation. Leptin or CCK-8s was injected to rats intraperitoneally immediately before and 6 h after the induction of colitis with acetic acid. CCK-A receptor antagonist (L-364,718) or CCK-B receptor antagonist (L-365,260) was injected intraperitoneally 15 min before leptin or CCK treatments. In a group of rats, vagal afferent fibers were denervated by topical application of capsaicin on the cervical vagi. Rats were decapitated at 24 h, and the distal 8 cm of the colon were removed for macroscopic scoring, determination of tissue wet weight index (WWI), histologic assessment and tissue myeloperoxidase (MPO) activity. All inflammation parameters were increased by acetic acid-induced colitis compared to control group. Leptin or CCK-8s treatment reduced these parameters in a similar manner, while co-administration of leptin and CCK was found to be more effective in reducing the macroscopic score and WWI. CCK-8s-induced reduction in the score and WWI was prevented by CCK-A, but not by CCK-B receptor antagonist, whereas neither antagonist altered the inhibitory effect of leptin on colitis-induced injury. On the other hand, perivagal capsaicin prevented the protective effects of both CCK-8s and leptin on colitis. Our results indicate that leptin and CCK have anti-inflammatory effects on acetic acid-induced colitis in rats, which appear to be mediated by capsaicin-sensitive vagal afferent fibers involving the reduction in colonic neutrophil infiltration.     

Studies of short-wavelength collective molecular motions in lipid bilayers using high resolution inelastic X-ray scattering

We summarize a series of experimental results made with the newly developed high resolution X-ray scattering (IXS) instrument on two pure lipid bilayers, including dimyristoylphosphatidylcholine (DMPC) and dilauroylphosphatidylcholine (DLPC) in both gel and liquid crystal phases, and lipid bilayers containing cholesterol. By analyzing the IXS data based on the generalized three effective eigenmode model (GTEE), we obtain dispersion relations of the high frequency density oscillations (phonons) of lipid molecules in these bilayers. We then compare the dispersion relations of pure lipid bilayers of different chain lengths among themselves and the dispersion relations of pure lipid bilayers with those of the cholesterol containing bilayers. We also compare our experimental results with collective dynamics data generated by computer molecular dynamics (MD) simulations for dipalmitoylphosphatidylcholine (DPPC) in gel phase and DMPC in liquid crystal phase.     

Necroptosis Interfaces with MOMP and the MPTP in Mediating Cell Death

During apoptosis the pro-death Bcl-2 family members Bax and Bak induce mitochondrial outer membrane permeabilization (MOMP) to mediate cell death. Recently, it was shown that Bax and Bak are also required for mitochondrial permeability transition pore (MPTP)-dependent necrosis, where, in their non-oligomeric state, they enhance permeability characteristics of the outer mitochondrial membrane. Necroptosis is another form of regulated necrosis involving the death receptors and receptor interacting protein kinases (RIP proteins, by Ripk genes). Here, we show cells or mice deficient for Bax/Bak or cyclophilin D, a protein that regulates MPTP opening, are resistant to cell death induced by necroptotic mediators. We show that Bax/Bak oligomerization is required for necroptotic cell death and that this oligomerization reinforces MPTP opening. Mechanistically, we observe mixed lineage kinase domain-like (MLKL) protein and cofilin-1 translocation to the mitochondria following necroptosis induction, while expression of the mitochondrial matrix isoform of the antiapoptotic Bcl-2 family member, myeloid cell leukemia 1 (Mcl-1), is significantly reduced. Some of these effects are lost with necroptosis inhibition in Bax/Bak1 double null, Ppif^-/-, or Ripk3^-/- fibroblasts. Hence, downstream mechanisms of cell death induced by necroptotic stimuli utilize both Bax/Bak to generate apoptotic pores in the outer mitochondrial membrane as well as MPTP opening in association with known mitochondrial death modifying proteins.     

Association of male pattern baldness with angiographic coronary artery disease severity and collateral development

Objective

We aimed to investigate whether there is an association between male pattern baldness and angiographic coronary artery disease (CAD) severity and collateral development, which has not been reported previously.

Methods

Coronary arteriograms, CAD risk factors, lipid parameters and presence and severity of baldness in 511 male patients were prospectively evaluated. Baldness was classified into five groups. Severity of CAD was evaluated with the Gensini scoring system and collateral development with Rentrop scores.

Results

Although subjects with a higher Gensini score had more frequent and severe baldness, they were older than the group with lower Gensini scores. Bald patients had a higher Gensini score when compared with their non-bald counterparts. In univariate analysis, age more than 60, body mass index more than 30, smoking and baldness were predictors of high Gensini scores. In multivariate analysis, only age more than 60, body mass index more than 30 and smoking were independent predictors of a high Gensini score. There were no differences in terms of presence and severity of baldness in subjects with and without adequate collateral development.

Conclusions

There was no relation between presence, severity and age of occurrence of male pattern baldness and Gensini and Rentrop scores, which are important measures of presence and severity of CAD.     

Highly stable laccase from repeated-batch culture of Funalia trogii ATCC 200800

The effect of temperature, pH, different inhibitors and additives on activity and stability of crude laccase obtained from repeated-batch culture of white rot fungus Funalia trogii ATCC 200800 was studied. The crude enzyme showed high activity at 55–90°C, which was maximal at 80–95°C. It was highly stable within the temperature intervals 20–50°C. The half life of the enzyme was about 2 h and 5 min at 60°C and 70°C, respectively. pH optimum of fungal laccase activity was revealed at pH 2.5. The enzyme from F. trogii ATCC 200800 was very stable between pH values of 3.0–9.0. NaN₃ and KCN were detected as the most effective potent enzyme inhibitors among different compounds tested. The fungal enzyme was highly resistant to the various metal ions, inorganic salts, and organic solvents except propanol, at least for 5 min. Because of its high stability and efficient decolorization activity, the use of the crude F. trogii ATCC 200800 laccase instead of pure enzyme form may be a considerably cheaper solution for biotechnological applications.