Proteomic analysis of serum opsonins impacting biodistribution and cellular association of porous silicon microparticles

Mass transport of drug delivery vehicles is guided by particle properties, such as size, shape, composition, and surface chemistry, as well as biomolecules and serum proteins that adsorb to the particle surface. In an attempt to identify serum proteins influencing cellular associations and biodistribution of intravascularly injected particles, we used two-dimensional gel electrophoresis and mass spectrometry to identify proteins eluted from the surface of cationic and anionic silicon microparticles. Cationic microparticles displayed a 25-fold greater abundance of Ig light variable chain, fibrinogen, and complement component 1 compared to their anionic counterparts. Anionic microparticles were found to accumulate in equal abundance in murine liver and spleen, whereas cationic microparticles showed preferential accumulation in the spleen. Immunohistochemistry supported macrophage uptake of both anionic and cationic microparticles in the liver, as well as evidence of association of cationic microparticles with hepatic endothelial cells. Furthermore, scanning electron micrographs supported cellular competition for cationic microparticles by endothelial cells and macrophages. Despite high macrophage content in the lungs and tumor, microparticle uptake by these cells was minimal, supporting differences in the repertoire of surface receptors expressed by tissue-specific macrophages. In summary, particle surface chemistry drives selective binding of serum components impacting cellular interactions and biodistribution.     

Rap1 regulates E-cadherin-mediated cell-cell adhesion

The small GTPase Rap is best characterized as a critical regulator of integrin-mediated cell adhesion, although its mechanism of action is not understood. Rap also influences the properties of other cell-surface receptors and biological processes, although whether these are a consequence of effects on integrins is not clear. We show here that Rap also plays an important role in the regulation of cadherin-mediated cell-cell adhesion in epithelial cells. Expression of constitutively active Rap1A restored cadherin-mediated cell-cell contacts in mesenchymal Ras-transformed Madin-Darby canine kidney cells, resulting in reversion to an epithelial phenotype. Activation of endogenous Rap via the Rap exchange factor Epac1 also antagonized hepatocyte growth factor-induced disruption of adherens junctions. Inhibition of Rap signaling resulted in disruption of epithelial cell-cell contacts. Rap activity was required for adhesion of cells to recombinant E-cadherin extracellular domains, i.e. in the absence of integrin-mediated adhesion. These findings suggest that Rap signaling positively contributes to cadherin-mediated adhesion and that this occurs independently of effects on integrin-mediated adhesion. Our results imply that Rap may function in a broader manner to regulate the function of cell-surface adhesion receptors.     

Low grade fibromyxoid sarcoma: report of a case with fine needle aspiration cytology and histologic correlation

BACKGROUND: Low grade fibromyxoid sarcoma has been fully described histologically; however, the fine needle aspiration (FNA) cytologic findings are scantily defined, and the distinction from other benign and malignant soft tissue tumors can be difficult. CASE: We examined FNA cytologic material from a slowly growing, large chest wall mass in a 28-year-old woman. The surgical specimen was processed for routine histology and immunohistochemical studies. The cytologic smears were adequately cellular, showing spindly cells with uniform, elongated nuclei; small, inconspicuous nucleoli; and scanty, wispy cytoplasm associated with myxoid material. No significant nuclear pleomorphism or mitoses were noted. The excised tumor was well circumscribed, focally infiltrating the surrounding muscles. The cut surface was variable, featuring fibrous, solid, fleshy and myxoid areas. Microscopically, the solid, fibrous areas displayed increased cellularity with storiform, intersecting and parallel patterns. In the myxoid areas the cells grew in a haphazard fashion and appeared floating in abundant mucoid matrix associated with a capillary vascular network similar to the chicken-wire pattern seen in cases of myxoid liposarcoma. The tumor cells were spindly, with fusiform, uniform nuclei. Focal, moderate nuclear pleomorphism was noted. The mitotic index was low. The tumor cells were positive for vimentin, alpha-1-antitrypsin and lysozyme and negative for S-100, actin, desmin and CD34. CONCLUSION: Although low grade fibromyxoid sarcoma is a rare neoplasm, it should be recognized and distinguished from other soft tissue tumors because of its low malignant potential. The definitive FNA cytologic diagnosis can be challenging but is possible if the tumor is adequately sampled, with multiple passes from different areas. Clinical and radiologic correlations are of great help. All spindle cell tumors with myxoid changes, such as myxoid liposarcoma, myxofibrosarcoma, cellular myxoma, myxoid leiomyosarcoma and peripheral nerve sheath tumors, should be considered in the differential diagnosis. In contrast to the cytologic features, the histologic findings are characteristic and well established.     

Comparison of the results of surgical and non-surgical treatment of combat urogenital injuries in Bosnia war 1992-1995

Goal was to compare the results of surgical and non-surgical treatments of combat injuries of genitourinary system and to compare our data with data collected in the recent studies. The study was designed as a retrospective review of data collected in prospective databases. The data extracted from inpatients' medical records included demographics, mechanisms and type of injury, distribution of the lesions, clinical presentation features, applied diagnostic studies, treatment modalities, types of complication and results of treatment. Among 4.125 patients treated in the Mostar War Hospital, 111 had injury of genitourinary tract: 62 underwent a surgical and 49 non-surgical treatment. Mortality among operated patients was 16 (26%). Complications were noted in 47 patients (42%); in 33 (70%) were manifested as early complications, and 14 (30) as delayed ones (p = 0.006). Among the surgically treated patients, 40 (36%) had some complication, in comparison to 8 (7.2%) patients with complications among non-surgically treated patients; which represent a statistically significant difference (p < 0.05). In this study, there was a surprisingly high number of non-surgically treated patients, and this sub-group of UGT trauma patients had in some ways the superior treatment results in comparison with surgically treated patients. Conservatively treated patients had lower rate of complications, no mortality, and no patients with permanent disability.     

Increased lipolysis but diminished gene expression of lipases in subcutaneous adipose tissue of healthy young males with intrauterine growth retardation

Intrauterine growth retardation (IUGR) is associated with a central fat distribution and risk of developing type 2 diabetes in adults when exposed to a sedentary Western lifestyle. Increased lipolysis is an early defect of metabolism in IUGR subjects, but the sites and molecular mechanisms involved are unknown. Twenty IUGR and 20 control (CON) subjects, aged 20-30 years, were studied before and after 10 days of bed rest using the glucose clamp technique combined with measurements of in vivo metabolism by microdialysis technique and blood flow by (133)Xe washout technique in subcutaneous abdominal (SCAAT) and femoral (SCFAT) adipose tissue. Additionally, mRNA expression of lipases was evaluated in biopsies from SCAAT. Lipolysis in SCAAT was substantially higher in IUGR than in CON subjects despite markedly lower mRNA expression of lipases. Blood flow was higher in IUGR compared with CON in both SCAAT and SCFAT. Whole body insulin sensitivity did not differ between groups and decreased after bed rest. After bed rest, SCAAT lipolysis remained higher in IUGR compared with CON, and SCFAT lipolysis decreased in CON but not in IUGR. Prior to the development of whole body insulin resistance, young men with IUGR are characterized by increased in vivo adipose tissue lipolysis and blood flow with a paradoxically decreased expression of lipases compared with CON, and 10 days of physical inactivity underlined the baseline findings. Subjects with IUGR exhibit primary defects in adipose tissue metabolism.     

Destruction of aflatoxins B1 and G1 in bread making

The effect of processing steps as well preservatives used in French bread making namely propionic acid and/or potassium sorbate (0.2%) on the destruction of aflatoxins B₁ and G₁ was studied. Mixing and baking processes showed marked destruction of aflatoxins B₁ and G₁; being 71.2% and 52.5% for aflatoxin B₁ after mixing and baking steps, while reaching 73.9% and 54.5% for aflatoxin G₁. Fermentation step caused additional 15.3% and 15.0% destruction of aflatoxins B₁ and G₁. On the other hand, aflatoxin B₁ destruction was 79.2% and 50.7% when propionic acid was used and 75.3 and 56.7% in the presence of potassium sorbate and after mixing and baking steps respectively. Concerning aflatoxins G₁ it was found that mixing and baking steps showed destruction of 81.9% and 53.4% in the presence of propionic acid and 75.1 and 49.4% in the presence of potassium sorbate in this respective order. Generally, it can be concluded that using propionic acid as preservative appeared to be more effective on the destruction of aflatoxins B₁ and G₁ than potassium sorbate in French bread making.     

The Phosphoinositide‐Gated Lysosomal Ca2+ Channel,TRPML1, Is Required for Phagosome Maturation

Macrophages internalize and sequester pathogens into a phagosome. Phagosomes then sequentially fuse with endosomes and lysosomes, converting into degradative phagolysosomes. Phagosome maturation is a complex process that requires regulators of the endosomal pathway including the phosphoinositide lipids. Phosphatidylinositol‐3‐phosphate and phosphatidylinositol‐3,5‐bisphosphate (PtdIns(3,5)P₂), which respectively control early endosomes and late endolysosomes, are both required for phagosome maturation. Inhibition of PIKfyve, which synthesizes PtdIns(3,5)P₂, blocked phagosome–lysosome fusion and abated the degradative capacity of phagosomes. However, it is not known how PIKfyve and PtdIns(3,5)P₂ participate in phagosome maturation. TRPML1 is a PtdIns(3,5)P₂‐gated lysosomal Ca²⁺ channel. Because Ca²⁺ triggers membrane fusion, we postulated that TRPML1 helps mediate phagosome–lysosome fusion. Using Fcγ receptor‐mediated phagocytosis as a model, we describe our research showing that silencing of TRPML1 hindered phagosome acquisition of lysosomal markers and reduced the bactericidal properties of phagosomes. Specifically, phagosomes isolated from TRPML1‐silenced cells were decorated with lysosomes that docked but did not fuse. We could rescue phagosome maturation in TRPML1‐silenced and PIKfyve‐inhibited cells by forcible Ca²⁺ release with ionomycin. We also provide evidence that cytosolic Ca²⁺ concentration increases upon phagocytosis in a manner dependent on TRPML1 and PIKfyve. Overall, we propose a model where PIKfyve and PtdIns(3,5)P₂ activate TRPML1 to induce phagosome–lysosome fusion.      

Potential protective effect of HSCAS and bentonite against dietary aflatoxicosis in rat: with special reference to chromosomal aberrations.

Bentonite and hydrated sodium calcium aluminsilicate (HSCAS) were added at a level of 0.5% (w/w) to the diets containing 2.5 mg aflatoxins (AF) per kg diet and fed to male mature rats for 15 successive days. Aflatoxin alone significantly decreased feed intake and altered serum biochemical parameters of liver and kidney functions. Aflatoxin caused chromosomal aberrations in bone marrow cells. Bentonite or HSCAS did not alter any of the parameters measured. The addition of bentonite or HSCAS to the AF-contaminated diet diminished most of the deleterious effects of the aflatoxin. Pathological examinations of liver and kidney proved that both bentonite and HSCAS were hepatonephroprotective agents against aflatoxicosis. The cytogenetic findings demonstrated that the addition of bentonite or HSCAS to AF-contaminated diet suppressed chromosomal aberrations. These findings indicated that bentonite and HSCAS could diminished many of the adverse effect of dietary AF in rats.     

Two plastid POLLUX ion channel-like proteins are required for stress-triggered stromal Ca2+release

Two decades ago, large cation currents were discovered in the envelope membranes of Pisum sativum L. (pea) chloroplasts. The deduced K⁺-permeable channel was coined fast-activating chloroplast cation channel but its molecular identity remained elusive. To reveal candidates, we mined proteomic datasets of isolated pea envelopes. Our search uncovered distant members of the nuclear POLLUX ion channel family. Since pea is not amenable to molecular genetics, we used Arabidopsis thaliana to characterize the two gene homologs. Using several independent approaches, we show that both candidates localize to the chloroplast envelope membrane. The proteins, designated PLASTID ENVELOPE ION CHANNELS (PEC1/2), form oligomers with regulator of K⁺ conductance domains protruding into the intermembrane space. Heterologous expression of PEC1/2 rescues yeast mutants deficient in K⁺ uptake. Nuclear POLLUX ion channels cofunction with Ca²⁺ channels to generate Ca²⁺ signals, critical for establishing mycorrhizal symbiosis and root development. Chloroplasts also exhibit Ca²⁺ transients in the stroma, probably to relay abiotic and biotic cues between plastids and the nucleus via the cytosol. Our results show that pec1pec2 loss-of-function double mutants fail to trigger the characteristic stromal Ca²⁺ release observed in wild-type plants exposed to external stress stimuli. Besides this molecular abnormality, pec1pec2 double mutants do not show obvious phenotypes. Future studies of PEC proteins will help to decipher the plant’s stress-related Ca²⁺ signaling network and the role of plastids. More importantly, the discovery of PECs in the envelope membrane is another critical step towards completing the chloroplast ion transport protein inventory.     

Comparing Observed with Predicted Weekly Influenza-Like Illness Rates during the Winter Holiday Break,United States, 2004-2013

In the United States, influenza season typically begins in October or November, peaks in February, and tapers off in April. During the winter holiday break, from the end of December to the beginning of January, changes in social mixing patterns, healthcare-seeking behaviors, and surveillance reporting could affect influenza-like illness (ILI) rates. We compared predicted with observed weekly ILI to examine trends around the winter break period. We examined weekly rates of ILI by region in the United States from influenza season 2003–2004 to 2012–2013. We compared observed and predicted ILI rates from week 44 to week 8 of each influenza season using the auto-regressive integrated moving average (ARIMA) method. Of 1,530 region, week, and year combinations, 64 observed ILI rates were significantly higher than predicted by the model. Of these, 21 occurred during the typical winter holiday break period (weeks 51–52); 12 occurred during influenza season 2012–2013. There were 46 observed ILI rates that were significantly lower than predicted. Of these, 16 occurred after the typical holiday break during week 1, eight of which occurred during season 2012–2013. Of 90 (10 HHS regions x 9 seasons) predictions during the peak week, 78 predicted ILI rates were lower than observed. Out of 73 predictions for the post-peak week, 62 ILI rates were higher than observed. There were 53 out of 73 models that had lower peak and higher post-peak predicted ILI rates than were actually observed. While most regions had ILI rates higher than predicted during winter holiday break and lower than predicted after the break during the 2012–2013 season, overall there was not a consistent relationship between observed and predicted ILI around the winter holiday break during the other influenza seasons.