Spatial Distribution of Platelet Deposition in Stented Arterial Models Under Physiologic Flow

This paper presents dynamic flow experiments with fluorescently labeled platelets to allow for spatial observation of wall attachment in inter-strut spacings, to investigate their relationship to flow patterns. Human blood with fluorescently labeled platelets was circulated through an in vitro system that produced physiologic pulsatile flow in a parallel plate flow chamber that contained three different stent designs that feature completely recirculating flow, partially recirculating flow (intermediate strut spacing), and completely reattached flow. Highly resolved spatial distribution of platelets was obtained by imaging fluorescently labeled platelets between the struts. Platelet deposition was higher in areas where flow is directed towards the wall, and lower in areas where flow is directed away from the wall. Flow detachment and reattachment points exhibited very low platelet deposition. Platelet deposition within intermediate strut spacing continued to increase throughout the experimental period, indicating that the deposition rate had not plateaued unlike other strut spacings. The spatial uniformity and temporal increase in platelet deposition for the intermediate strut spacing confirms and helps explain our previous finding that platelet deposition was highest with this strut spacing. Further experimental investigations will include more complex three-dimensional geometries.     

Mechanism of the immunomodulatory activity of glycodelin

Glycodelin, a progesterone regulated protein synthesized by the endometrium (GdA) has been well documented to inhibit the proliferation of activated T-cells and is an indispensable molecule in the maternal system for the establishment, maintenance and progression of pregnancy. Data from our laboratory have unequivocally shown that the immunosuppression by GdA is via induction of apoptosis in activated T cells. Another isoform of glycodein, GdS, from the male reproductive system, in spite of sharing an identical amino acid sequence as that of GdA has been shown not to harbour the immunosuppressive activity of GdA. As the only difference between the two proteins is glycosylation, we proposed to study the role of the sugars in imparting apoptotic activity to Gd. Using the recombinant baculovirus system, Gd lacking glycosylation was expressed and from the experimental observations we could conclude that the activity of Gd lies in the protein backbone. Recombinant Gd expressed in P. pastoris, and Chinese hamster ovary cells, like the GdS did not exhibit apoptotic activity. A close analyses of the glycans associated with the Gd molecules from various sources suggested that though the apoptogenic activity of Gd lies in the protein backbone, the glycans modulate the activity by masking (as in case of GdS and most recombinant Gd expressed in our laboratory) or unmasking (as in case of GdA and baculovirus expressed Gd), the functional region of the molecule.     

Contralateral drainage of primary hydrocele

The authors propose a simple surgical approach for the treatment of primary hydrocele.     

Physiological concentration of 17beta-estradiol retards the progression of severe atherosclerosis induced by a high-cholesterol diet plus balloon catheter injury: role of NO

The molecular mechanisms of the antiatherosclerotic effects of estrogen are not yet known. We evaluated the effects of 17beta-estradiol (E(2)) on high cholesterol diet- (HCD; standard diet and 1% cholesterol) and balloon injury-induced atherosclerosis in female New Zealand White rabbits. The abdominal aortas of 40 oophorectomized (Groups 1 through 5) and 8 nonoophorectomized (Group 6) rabbits were injured by balloon catheter, and the animals were then divided into the following groups and treated for 10 weeks: Group 1, standard diet; Group 2, standard diet plus a moderate dose of E(2) (100 microg x kg(-1) x d(-1)); Group 3, HCD; Group 4, HCD plus a moderate dose of E(2); Group 5, HCD plus a low dose of E(2) (20 microg x kg(-1) x d(-1)); and Group 6, HCD in nonoophorectomized rabbits. After the treatment phase, plasma E(2) was increased up to 282.2+/-45.5 pg/mL in Group 2, 263.0+/-41.5 pg/mL in Group 4, 87. 9+/-18.8 pg/mL in Group 5, and 45.6+/-7.3 pg/mL in Group 6. HCD-mediated increases in plasma lipid levels were not changed by E(2) treatment, whereas E(2) decreased the aortic intimal thickening in Group 2 animals compared with those in Group 1 and reduced atherosclerosis in the thoracic and abdominal aortas of Group 4, 5, and 6 rabbits compared with those in Group 3. E(2) restored the impaired abdominal aortic endothelium-dependent relaxation of balloon-injured and HCD-supplemented rabbits, and E(2) increased basal nitric oxide (NO) release. The basal NO-releasing effect showed a significant, inverse relation with the severity of atherosclerosis. Plasma E(2) concentration also showed a significant, inverse relation with atherosclerotic area. In conclusion, physiological concentrations of E(2) can retard the progression of severe atherosclerosis and stabilize atheromas induced by HCD and balloon injury. The retardation may be partially mediated by endothelial NO function in vessels treated with E(2).     

Melioidosis—an unusual cause of septic arthritis

Melioidosis is an infection caused by Burkholderia pseudomallei. It is an important human pathogen in the tropical area. The clinical manifestations are protean with multisystem involvement. Septic arthritis and prostatic abscess are rare but well-recognized forms of the disease. Herein we report a case of melioidosis presenting with a rare combination of septic arthritis, prostatic abscess, and septicemia.     

Perception and prevalence of work-related health hazards among health care workers in public health facilities in southern India

Background:

Health care workers (HCWs) are exposed to occupational related health hazards. Measuring worker perception and the prevalence of these hazards can help facilitate better risk management for HCWs, as these workers are envisaged to be the first point of contact, especially in resource poor settings.

Objective:

To describe the perception of occupational health hazards and self-reported exposure prevalence among HCWs in Southern India.

Methods:

We used cross sectional design with stratified random sampling of HCWs from different levels of health facilities and categories in a randomly selected district in Southern India. Data on perception and exposure prevalence were collected using a structured interview schedule developed by occupational health experts and administered by trained investigators.

Results:

A total of 482 HCWs participated. Thirty nine percent did not recognize work-related health hazards, but reported exposure to at least one hazard upon further probing. Among the 81·5% who reported exposure to biological hazard, 93·9% had direct skin contact with infectious materials. Among HCWs reporting needle stick injury, 70·5% had at least one in the previous three months. Ergonomic hazards included lifting heavy objects (42%) and standing for long hours (37%). Psychological hazards included negative feelings (20·3%) and verbal or physical abuse during work (20·5%).

Conclusion:

More than a third of HCWs failed to recognize work-related health hazards. Despite training in handling infectious materials, HCWs reported direct skin contact with infectious materials and needle stick injuries. Results indicate the need for training oriented toward behavioral change and provision of occupational health services.     

Simulations of the role of water in the protein-folding mechanism

There are many unresolved questions regarding the role of water in protein folding. Does water merely induce hydrophobic forces, or does the discrete nature of water play a structural role in folding? Are the nonadditive aspects of water important in determining the folding mechanism? To help to address these questions, we have performed simulations of the folding of a model protein (BBA5) in explicit solvent. Starting 10,000 independent trajectories from a fully unfolded conformation, we have observed numerous folding events, making this work a comprehensive study of the kinetics of protein folding starting from the unfolded state and reaching the folded state and with an explicit solvation model and experimentally validated rates. Indeed, both the raw TIP3P folding rate (4.5 +/- 2.5 micros) and the diffusion-constant corrected rate (7.5 +/- 4.2 micros) are in strong agreement with the experimentally observed rate of 7.5 +/- 3.5 micros. To address the role of water in folding, the mechanism is compared with that predicted from implicit solvation simulations. An examination of solvent density near hydrophobic groups during folding suggests that in the case of BBA5, there are water-induced effects not captured by implicit solvation models, including signs of a "concurrent mechanism" of core collapse and desolvation.     

Assessment of the Synergetic Performance of Nanostructured CeO2-SnO2/Al2O3 Mixed Oxides on Automobile Exhaust Control

In order to control diesel exhaust emission, CeO₂-SnO₂/Al₂O₃ (CTA) mixed oxides were prepared and coated on perforated stainless steel (SS) filter plates, and the catalytic activities were analyzed in this work. The CeO₂-SnO₂ (different compositions of Ce/Sn—2:8; 1:1; 8:2) composites and Al₂O₃ were prepared separately via a co-precipitation approach, and CeO₂-SnO₂/Al₂O₃ (CTA) mixed oxides were attained by mechanical mixing of 75 wt% CeO₂-SnO₂ composites with 25 wt% Al₂O₃. X-ray diffraction (XRD) and Raman spectroscopy were performed for all three CeO₂-SnO₂/Al₂O₃ (CTA) mixed oxides; the CeO₂-SnO₂/Al₂O₃ (Ce/Sn-1:1) sample confirmed the presence of cubic and tetragonal mixed faces, which enhances the redox nature (catalytic activities). Various characterizations such as high-resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), and a scanning electron microscope (SEM) were employed on CeO₂-SnO₂/Al₂O₃ (Ce/Sn-1:1) sample to investigate the structural, textural, compositional, and morphological properties. The CeO₂-SnO₂/Al₂O₃ (Ce/Sn-1:1) sample was coated on a perforated stainless steel (SS) filter plate via a simple, cost-effective, and novel method, and an exhaust emission test for various compression ratios (CR), injection pressure (IP), and load (L) was completed using an AVL Digas analyzer. The CeO₂-SnO₂/Al₂O₃ (Ce/Sn-1:1) sample, with a size of 10.22 nm and a high surface area of about 73 m² g⁻¹, exhibit appreciable catalytic properties.