Processing and characterization of antimicrobial bioplastic films based on green microalgae Scenedesmus obliquus extract-loaded polyurethane.

The green microalga Scenedesmus obliquus, isolated from the Egyptian environment, was used for the synthesis of bio-based plastic materials. Polyurethane (PU) was blended with different proportions (0%, 10%, 20%, and 40%) of chloroform extract to form bioplastic films. The bioplastic films were characterized using water vapor transmission rate measurements and scanning electron microscopy (SEM). The WVTR of pure PU was 193.37 g/m2. day, while the values of algae/PU films were 129.74, 122.56, and 99.75 g/m2.day. S. obliquus reported having Palmitic, which possesses antimicrobial activity and acts as an effective antimicrobial agent in the synthesized bioplastic films. Antimicrobial activity of the algal extract and the synthesized bioplastic films were tested against two Gram-positive bacteria; Staphylococcus aureus, Enterococcus faecalis, two Gram-negative bacteria; Escherichia coli, Pseudomonas aeruginosa, and Candida albicans as a model for fungi. The results indicated that S. obliquus extract exhibited a clear antimicrobial activity against all tested microbes. The antimicrobial rate of bioplastic films containing 40% of the extract reached 100% after 2 h of contact with E. coli and E. faecalis. In conclusion, this study offers a promising future for the use of biodegradable antimicrobial bioplastic films as an affordable and environmentally friendly alternative to plastics in many applications.

The home environment and toddler physical activity: an ecological momentary assessment study.

BACKGROUND: Physical activity (PA) promotion/obesity prevention in toddlerhood should include home environments. OBJECTIVE: The aim of the study was to determine social/physical home environment factors associated with toddler PA using ecological momentary assessment (EMA, real-time data collection). METHODS: Low-income mother-toddler dyads were recruited and given a handheld EMA device (53 random beeps followed by social/physical environment survey over 8 d). Simultaneously, PA was assessed via accelerometry (data extracted 15 min before/after response, average activity counts per minute). Linear mixed-effects models were used, adjusting for toddler age, urban/suburban residence and time of day; covariate moderating effects were examined; within-subjects and between-subjects findings were reported. PA was hypothesized to be greater when toddlers are outside (vs. inside), children are nearby (vs. alone), toddlers are interacting with their mothers (vs. not) and TV is off (vs. on). RESULTS: The final count was 2454 EMA/PA responses for 160 toddlers (mean age 20 months, range 12-31; 55% male, 66% Black and 54% urban). Associations with PA include (within subjects) the following: outside location (212 additional counts min-1 ), children nearby (153 additional counts min-1 ) and interacting with mother (321 additional counts min-1 ), compared with alternatives. Age was moderated by outside location/PA association (within subjects), with 90 additional counts min-1 per 3-month age group outside vs. inside. No between-subjects or television/PA associations were found. CONCLUSIONS: Home environment factors were associated with PA, including outside location, children nearby and mother interaction. EMA is a novel method, allowing identification of contextual factors associated with behaviours in natural environments.

Choosing the correct treatment for acute aortic type B dissection.

Acute type B aortic dissection is a life threatening disease process, which remains a clinical dilemma despite advances in technology, surgical technique and postoperative management. The variability of presenting symptoms, lack of a consensus on indications for treatment and differing opinions about the optimal timing for repair have added to the management confusion. Medical management has been the standard of care for acute uncomplicated type B dissection. Surgical repair and endovascular intervention are reserved for those who present with, or subsequently develop, dissection-related complications. Complicated dissections occur in 25% of cases and may include organ malperfusion, aortic rupture, periaortic hematoma, and uncontrolled hypertension. In the past decade thoracic endovascular aortic repair (TEVAR) has gained widespread acceptance as the modality of choice for the treatment of complicated type B dissection. This transition is representative of advances in technology, physician experience with aortic endografts and lower morbidity and mortality rates associated with TEVAR. The best medical therapy remains the standard of care for uncomplicated dissection, however this strategy fails to prevent long-term aortic-related morbidity and mortality. Recent data suggest that early TEVAR lowers aortic-related events and improves long-term aortic specific survival by covering the entry tear, promoting false lumen thrombosis and inducing aortic wall remodeling. The paucity of supporting data has created controversy surrounding the optimal treatment strategy for acute type B dissection. Nonetheless, recent healthcare trends show a paradigm shift towards the utilization of early TEVAR in acute type B dissection.

Ruptured abdominal aortic aneurysms: is open surgery an outdated operation?

The advent of endovascular aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysms. EVAR has evolved into the preferred treatment for abdominal aortic aneurysms with suitable anatomy. Several randomized clinical trials have confirmed that EVAR reduces short-term morbidity and mortality. Despite vast improvements in diagnostic imaging, open surgical repair techniques and the care of critically ill patients over the past two decades rupture of abdominal aortic aneurysms still carries an extremely high morbidity and mortality. To improve outcomes in treatment of rAAA a movement has occurred away from open repair and toward EVAR as a paradigm shift that may help to improve otherwise dismal results. In the past 10 years, numerous studies including meta-analyses, administrative databases and randomized control trials have investigated the presumed advantages of EVAR over open repair. This review summarizes the world wide experience for ruptured AAA repair and addresses the role for standardization of care with the use of aortic aneurysm protocols.

Deletion of a single mevalonate kinase (Mvk) allele yields a murine model of hyper-IgD syndrome.

In the current study our objective was to develop a murine model of human hyper-IgD syndrome (HIDS) and severe mevalonic aciduria (MA), autoinflammatory disorders associated with mevalonate kinase deficiency (MKD). Deletion of one Mvk allele (Mvk (+/-)) yielded viable mice with significantly reduced liver Mvk enzyme activity; multiple matings failed to produce Mvk (-/-) mice. Cholesterol levels in tissues and blood, and isoprene end-products (ubiquinone, dolichol) in tissues were normal in Mvk (+/-) mice; conversely, mevalonate concentrations were increased in spleen, heart, and kidney yet normal in brain and liver. While the trend was for higher IgA levels in Mvk (+/-) sera, IgD levels were significantly increased (9-12-fold) in comparison to Mvk (+/+) littermates, in both young (<15 weeks) and older (>15 weeks) mice. Mvk (+/-) animals manifested increased serum TNF-alpha as compared to wild-type littermates, but due to wide variation in levels between individual Mvk (+/-) mice the difference in means was not statistically significant. Mvk (+/-) mice represent the first animal model of HIDS, and should prove useful for examining pathophysiology associated with this disorder.

Effects of combined water potential and temperature stresses on Cryptosporidium parvum oocysts.

Hosts infected with the parasite Cryptosporidium parvum may excrete oocysts on soils in watersheds that supply public drinking water. Environmental stresses decrease the numbers of oocysts after deposition on soils. However, the rates and effects of combined stresses have not been well characterized, especially for the purposes of estimating decrease in numbers. We subjected oocysts to combined stresses of water potential (-4, -12, and -33 bars), above-freezing temperatures (4 and 30 degrees C), and a subfreezing temperature (-14 degrees C) for 1, 14, and 29 days and one to six freeze-thaw cycles (-14 to 10 degrees C) to estimate coefficients to characterize population degradation using multiplicative error and exponential decay models. The experiments were carried out in NaCl solutions with water potentials of -4, -12, and -33 bars, in combination with temperature stresses at levels that could be expected in natural soils. Increased water potential increased the rate of population degradation for all temperature conditions investigated. Enhanced degradation leads to estimated rates of population degradation that are greater than those that have been reported and used in previous studies conducted to assess risk of water supply contamination from sources of C. parvum.

Intraperitoneal hyperthermic perfusion chemotherapy of patients with chemotherapy-resistant peritoneal disseminated ovarian cancer.

The purpose of this article is to evaluate in a prospective, open-label clinical trial the feasibility and efficacy of intraperitoneal hyperthermic perfusion chemotherapy (IPHC) on the survival and quality of life of patients with advanced, peritoneal disseminated ovarian cancer. Thirty-six patients with ovarian cancer were accrued for the study, their selection being based on their progression following different systemic therapies with anti-neoplastic (multiple chemotherapy-resistant or -refractory) agents. The average number of chemotherapy cycles given before the first IPHC was 12.5. The patients' average Karnofsky-performance status was 60% and 17 out of 36 patients had ascites before IPHC. The input temperature of the solution for abdominal lavage was 48-49 degrees C: the intraperitoneal temperature was 42-43 degrees C. The flow-rate of the solution for heat exchange was 190-220 ml/min with treatment lasting 1 h at temperatures greater than or equal to 42 degrees C. Median overall survival time (MOS) from first diagnosis of disease (1stDx) was 49 +/- 8 months and from the first IPHC-treatment 19 +/- 4 months. The observed 1-year overall survival rate (OSR) of all patients from the start of the first IPHC was 65 +/- 8% and the 5-year OSR was 16 +/- 7%. Malignant ascites vanished within less than 3-5 IPHCs. Quality of life could be improved. The adverse effects were mild especially compared to systemic chemotherapy. In 3 out of 162 treatments, peritoneal disturbances with symptoms of subileus were observed. We conclude that IPHC is technically feasible, safe, and associated with a marked prolongation of survival and improvement in quality of life. Even heavily pretreated patients could be treated safely. Some patients did respond to IPHC even after 25 IPHC treatments. From these results, it can be concluded that IPHC may also improve the treatment outcome of patients with ovarian cancer as salvage therapy, in second-line treatment or even as consolidation or maintenance therapy following induction chemotherapy to patients with suboptimal stage III and IV disease. This should be demonstrated in randomized controlled studies.

Identification and characterization of spdR mutations that bypass the BsgA protease-dependent regulation of developmental gene expression in Myxococcus xanthus.

The BsgA protease of Myxococcus xanthus is an intracellular protease closely related to the Lon protease of Escherichia coli. BsgA is required for normal levels of developmentally induced gene expression. In this report, we describe the identification of mutations that suppress the developmental defect of bsgA mutants. These mutations localized to the spdR gene (suppressor protease deficiency regulator) that appears to play a role in the regulation of early developmental gene expression. Mutations in spdR fully restored the ability of a bsgA mutant to form fruiting bodies and spores and, with one exception, restored the expression of several development-specific lacZ fusions. spdR mutants exhibited characteristic phenotypic properties including increased expression of the development-specific tps gene during vegetative growth, formation of fruiting bodies and spores on semi-rich nutrient medium and completion of starvation-induced development in a shorter time period than wild-type strains. The spdR locus was cloned and sequenced and found to encode a member of the NtrC family of two-component transcriptional regulators. One interpretation of these data is that SpdR acts, directly or otherwise, to regulate developmental gene expression negatively and that the BsgA protease is required to relieve this inhibitory effect at the onset of development. However, Western immunoblot analysis indicated that SpdR is present at a relatively constant level during growth and early development in both wild-type and BsgA protease-deficient cells. This finding suggests that BsgA does not function to degrade SpdR at the onset of development.

Effects of lithium on thrombopoiesis in patients with low platelet cell counts following chemotherapy or radiotherapy.

Therapy for neoplasma is limited by hematological side effects of tumor-destructive therapy and, in part, makes expensive supportive care necessary to overcome and treat leukopenia and thrombocytopenia and their consequences. Thrombocytopenia is a major clinical problem caused by chemotherapy and radiotherapy. An effective and very cost-effective option for treating moderate neutropenia is the administration of lithium carbonate. Lithium induces the release of colony-stimulating factors (CSF) and therefore stimulates proliferation of neutrophil granulocytes. Other cytokines, such as interleukin-1 (IL-1), IL-6, and tumor-necrosis factor-alpha (TNF-alpha), are also stimulated. Apart from granulocyte-macrophage-CSF (GM-CSF), there have as yet been no reports of lithium salts inducing early activating factors for the megakaryocytic lineage, such as IL-3, IL-11, stem cell factor and flt-3 ligand, or maturation factors, such as thrombopoietin (TPO). A statistically significant increase in the mean number of platelets for patients with cell counts below 150,000/microL on the commencement of treatment with lithium carbonate could be observed. Patient tolerability of lithium carbonate therapy is very good. Patients with persistent leukopenia and thrombocytopenia following chemotherapy or radiotherapy can be treated with this trace element very cost-effectively. Unfortunately this treatment has not gained acceptance in clinical oncology in the face of extremely cost-intensive treatment with recombinant GM-CSF, IL-11 or, potentially, thrombopoietin.

pH-regulated activation and release of a bacteria-associated phospholipase C during intracellular infection by Listeria monocytogenes.

Listeria monocytogenes grows in the cytosol of mammalian cells and spreads from cell to cell without exiting the intracellular milieu. During cell-cell spread, bacteria become transiently entrapped in double-membrane vacuoles. Escape from these vacuoles is mediated in part by a bacterial phospholipase C (PC-PLC), whose activation requires cleavage of an N-terminal peptide. PC-PLC activation occurs in the acidified vacuolar environment. In this study, the pH-dependent mechanism of PC-PLC activation was investigated by manipulating the intracellular pH of the host. PC-PLC secreted into infected cells was immunoprecipitated, and both forms of the protein were identified by SDS-PAGE fluorography. PC-PLC activation occurred at pH 7.0 and lower, but not at pH 7.3. Total amounts of PC-PLC secreted into infected cells increased several-fold over controls within 5 min of a decrease in intracellular pH, and the active form of PC-PLC was the most abundant species detected. Bacterial release of active PC-PLC was dependent on Mpl, a bacterial metalloprotease that processes the proform (proPC-PLC), and did not require de novo protein synthesis. The amount of proPC-PLC released in response to a decrease in pH was the same in wild-type and Mpl-minus-infected cells. Immunofluorescence detection of PC-PLC in infected cells was performed. When fixed and permeabilized infected cells were treated with a bacterial cell wall hydrolase, over 97% of wild-type and Mpl-minus bacteria stained positively for PC-PLC, in contrast to less than 5% in untreated cells. These results indicate that intracellular bacteria carry pools of proPC-PLC. Upon cell-cell spread, a decrease in vacuolar pH triggers Mpl activation of proPC-PLC, resulting in bacterial release of active PC-PLC.

Deep hyperthermia with radiofrequencies in patients with liver metastases from colorectal cancer.

Patients at advanced stage of colorectal cancer with liver metastases have been treated with deep hyperthermia alone or in combination with chemotherapy (5-FU + FA + MMC). Hyperthermia was achieved by arrangements of capacitive electrodes with a radiofrequency field of 13.56 MHz (RF-DHT). This prospective open single-arm clinical study with 80 patients suffering from liver metastases from colorectal cancer gives some first hints, that deep RF-hyperthermia alone may have a substantial beneficial effect on overall survival time of patients with liver metastases from colorectal cancer. Long lasting no-change, partial and even some complete remissions could be observed. The overall median survival time from progression of metastases or relapse was 24.5 months and survival rates at 1, 2 or 3 years from first diagnosis of metastases or progression were twice as high as expected from patients treated with chemotherapy. The combination of hyperthermia with delayed chemotherapy did not change overall survival time. These encouraging results deserve to be confirmed in randomized clinical studies.

New mosquito records for South Carolina.

Two species of mosquitoes, Mansonia dyari and Orthopodomyia alba, are reported for the first time in South Carolina. Collection data and identification characters are included.

Developmentally regulated expression of three slow isoforms of myosin heavy chain: diversity among the first fibers to form in avian muscle.

At least three slow myosin heavy chain (MHC) isoforms were expressed in skeletal muscles of the developing chicken hindlimb, and differential expression of these slow MHC isoforms produced distinct fiber types from the outset of skeletal muscle myogenesis. Immunohistochemistry with isoform-specific monoclonal antibodies demonstrated differences in MHC content among the fibers of the dorsal and ventral premuscle masses and distinctions among fibers before splitting of the premuscle masses into individual muscles (Hamburger and Hamilton Stage 25). Immunoblot analyses by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of myosin extracted from the hindlimb demonstrated the presence throughout development of different mobility classes of MHCs with epitopes associated with slow MHC isoforms. Immunopeptide mapping showed that one of the MHCs expressed in the embryonic limb was the same slow MHC isoform, slow MHC1 (SMHC1), that is expressed in adult slow muscles. SMHC1 was expressed in the dorsal and ventral premuscle masses, embryonic, fetal, and some neonatal and adult hindlimb muscles. In the embryo and fetus SMHC1 was expressed in future fast, as well as future slow muscles, whereas in the adult only the slow muscles retained expression of SMHC1. Those embryonic muscles destined in the adult to contain slow fibers or mixed fast/slow fibers not only expressed SMHC1, but also an additional slow MHC not previously described, designated as slow MHC3 (SMHC3). Slow MHC3 was shown by immunopeptide mapping to contain a slow MHC epitope (reactive with mAb S58) and to be structurally similar to a MHC expressed in the atria of the adult chicken heart. SMHC3 was designated as a slow MHC isoform because (i) it was expressed only in those muscles destined to be of the slow type in the adult, (ii) it was expressed only in primary fibers of muscles that subsequently are of the slow type, and (iii) it had an epitope demonstrated to be present on other slow, but not fast, isoforms of avian MHC. This study demonstrates that a difference in phenotype between fibers is established very early in the chicken embryo and is based on the fiber type-specific expression of three slow MHC isoforms.

Alpha-chains of IgM and IgD antigen receptor complexes are differentially N-glycosylated MB-1-related molecules.

The major B cell Ag receptors, membrane (m) IgM and mIgD, are noncovalently associated with disulfide-linked heterodimers of alpha, beta, and gamma glycoproteins. The beta and gamma chains have apparent molecular masses of 37 and 34 kDa, respectively, and are associated with both mIgM and mIgD. Receptor alpha chains, however, exhibit Ig isotype specificity. IgM-alpha and IgD-alpha have apparent molecular masses of 32 and 33 kDa, respectively. Recently, the alpha chain of the IgM Ag receptor complex was identified as the product of the mb-1 gene, and the beta and gamma chains were characterized as products of the B29 gene. The failure of mb-1 cDNA to hybridize with mRNA from J558 delta m2.6 plasmacytomas expressing surface mIgD in association with IgD-alpha has led to the conclusion that IgM-alpha and IgD-alpha are not closely related. In this report we have used protein biochemical methods to characterize differences in the mIgM- and mIgD-associated alpha chains. In addition to a slightly greater apparent m.w., IgD-alpha was slightly more acidic than IgM-alpha. The alpha chains had nearly identical proteolytic peptide maps, and were also noted to have multiple loci of identity with MB-1 based on amino terminal sequencing and immunoblotting. In an attempt to determine whether the alpha chains differed as a result of differential posttranslational modification, they were compared after deglycosylation with N-glycanase. The results indicate that the apparent m.w. as well as isoelectric point differences are primarily due to differential N-linked glycosylation. These studies indicate that IgM-alpha and IgD-alpha are products of the mb-1 gene or closely related genes.

IgM antigen receptor complex contains phosphoprotein products of B29 and mb-1 genes.

Membrane immunoglobulin M (mIgM) and mIgD are major B-lymphocyte antigen receptors, which function by internalizing antigens for processing and presentation to T cells and by transducing essential signals for proliferation and differentiation. Although ligation of mIgM or mIgD results in rapid activation of a phospholipase C and a tyrosine kinase(s), these receptors have cytoplasmic tails of only three amino acid residues (Lys-Val-Lys), which seem ill suited for direct physical coupling with cytoplasmic signal transduction structures. In this report, we identify the alpha, beta, and gamma components of the mIgM-associated phosphoprotein complex, which may play a role in signal transduction. Proteolytic peptide mapping demonstrated that the IgM-alpha chain differs from Ig-beta and Ig-gamma. The chains were purified, and amino-terminal sequencing revealed identity with two previously cloned B-cell-specific genes. One component, IgM-alpha, is a product of the mb-1 gene, and the two additional components, Ig-beta and Ig-gamma, are products of the B29 gene. Immunoblotting analysis using rabbit antibodies prepared against predicted peptide sequences of each gene product confirmed the identification of these mIgM-associated proteins. The deduced sequence indicates that these receptor subunits lack inherent protein kinase domains but include common tyrosine-containing sequence motifs, which are likely sites of induced tyrosine phosphorylation.

Ultrastructural analysis of polytene chromatin of Drosophila melanogaster reveals clusters of tightly linked co-expressed genes.

Patterns of gene activity on individual chromatids of polytene chromosomes of Drosophila melanogaster white prepupae were ultrastructurally characterized by electron microscopy. The band-interband structure of salivary gland polytene chromosomes is lost when they are dispersed in a low ionic strength detergent solution. Morphologically similar, active genes in close proximity to one another were seen in dispersed white prepupal chromatin. The arrays of genes almost certainly represent sister copies of the same locus. Although lateral register between gene copies on multiple strands was not maintained, analysis of sister transcriptional units of unknown identity was achieved at the periphery of the chromatin arrays. Juxtaposed genes with divergent transcriptional polarity were prevalent. The morphology, size and transcriptional polarity of multiple copies of short, tandemly organized, RNA polymerase dense, co-expressed gene clusters is reported. One highly transcriptionally active region, designated the white prepupal locus (WPP locus), composed of a co-expressed tandem cluster of ten genes within an approximately 50 kb region was analyzed on six separate chromatids. The transcriptional map suggests that the pattern of gene activity for at least one gene within the cluster may not be identical on all homologous strands. The survey of active polytene genes provides ultrastructural correlation with previous molecular data that demonstrate tight linkage of certain developmentally co-regulated Drosophila genes. Our findings are discussed in relation to Drosophila gene organization, clustering, and regulation of gene expression.