Molecular lemmings: strategies to avoid when designing BODIPY ferrocene dyads for dye-sensitized solar cell applications.

BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes) dyes possess intense absorption profiles that can be exploited in various light harvesting applications. However, redox stability and optimization of frontier molecular orbital energies in these dyes are critical for their successful incorporation into new solar cell materials. This article describes the synthesis and characterization of a family of ß-substituted BODIPY-ferrocene dyads with push-pull architectures. Designed to stabilize the photo-oxidized BODIPY for dye-sensitized solar cell (DSSC) applications, some deleterious electron transfer behaviours emerged when the ferrocene unit was conjugated to electron deficient BODIPYs. These findings are discussed herein.

Synchronizing single-shot high-energy iodine photodissociation laser PALS and high-repetition-rate femtosecond Ti:sapphire laser system.

A system of precise pulse synchronization between a single-shot large-scale laser exploiting an acousto-optical modulator and a femtosecond high repetition rate laser is reported in this article. This opto-electronical system has been developed for synchronization of the sub-nanosecond kJ-class iodine photodissociation laser system (Prague Asterix Laser System-PALS) with the femtosecond 25-TW Ti:sapphire (Ti:Sa) laser operating at a repetition rate 1 kHz or 10 Hz depending on the required energy level of output pulses. At 1 kHz synchronization regime, a single femtosecond pulse of duration about 45 fs and a small energy less than 1 mJ are exploited as a probe beam for irradiation of a three-frame interferometer, while at 10 Hz repetition rate a single femtosecond pulse with higher energy about 7-10 mJ is exploited as a probe beam for irradiation of a two-channel polaro-interferometer. The synchronization accuracy ±100 ps between the PALS and the Ti:Sa laser pulses has been achieved in both regimes of synchronization. The femtosecond interferograms of laser-produced plasmas obtained by the three-frame interferometer and the femtosecond polarimetric images obtained by the two-frame polaro-interferometer confirm the full usefulness and correct functionality of the proposed method of synchronization.

Monitoring complete and incomplete abscission in the germ line stem cell lineage of Drosophila ovaries.

In most species, cytokinesis is blocked in germ cells during at least some stage of their development. Abscission is difficult to assess directly in germ cells which are located in internal organs. Here, we described several indirect and direct methods to monitor the completion of abscission in Drosophila germ line cells. These methods are based on the observation that cells still connected by some cytoplasm share some degree of synchronization of their cell cycle. This synchrony can be detected on fixed tissue (Section 1.1), including using EdU incorporation to label S-phase (Section 1.2). Mitotic synchrony can also be observed using short-term live imaging (Section 1.3). Finally, we describe how the completion of abscission can be monitored using photoactivatable markers diffusing or not between two cells (Section 1.4).

Activation of µ opioid receptors modulates inflammation in acute experimental colitis.

BACKGROUND: µ opioid receptors (µORs) are expressed by neurons and inflammatory cells, and mediate immune response. We tested whether activation of peripheral µORs ameliorates the acute and delayed phase of colitis. METHODS: C57BL/6J mice were treated with 3% dextran sodium sulfate (DSS) in water, 5 days with or without the peripherally acting µOR agonist, [D-Ala2, N-Me-Phe4, Gly5-ol]-Enkephalin (DAMGO) or with DAMGO+µOR antagonist at day 2-5, then euthanized. Other mice received DSS followed by water for 4 weeks, or DSS with DAMGO starting at day 2 of DSS for 2 or 3 weeks followed by water, then euthanized at 4 weeks. Disease activity index (DAI), histological damage, and myeloperoxidase assay (MPO), as index of neutrophil infiltration, were evaluated. Cytokines and µOR mRNAs were measured with RT-PCR, and nuclear factor-kB (NF-kB), the antiapoptotic factor Bcl-xL, and caspase 3 and 7 with Western blot. KEY RESULTS: DSS induced acute colitis with elevated DAI, tissue damage, apoptosis and increased MPO, cytokines, µOR mRNA, and NF-kB. DAMGO significantly reduced DAI, inflammatory indexes, cytokines, caspases, and NF-kB, and upregulated Bcl-xL, effects prevented by µOR antagonist. In DSS mice plus 4 weeks of water, DAI, NF-kB, and µOR were normal, whereas MPO, histological damage, and cytokines were still elevated; DAMGO did not reduce inflammation, and did not upregulate Bcl-xL. CONCLUSIONS & INFERENCES: µOR activation ameliorated the acute but not the delayed phase of DSS colitis by reducing cytokines, likely through activation of the antiapoptotic factor, Bcl-xL, and suppression of NF-kB, a potentiator of inflammation.

A systematic review of placental pathology in maternal diabetes mellitus.

INTRODUCTION: During a pregnancy complicated by diabetes, the human placenta undergoes a number of functional and structural pathologic changes, such as increased placental weight and increased incidence of placental lesions including villous maturational defects and fibrinoid necrosis. The pathologic findings reported have differed among studies, potentially reflecting differences in type of diabetes, study methodology, or glycemic control of study participants. Alternatively, these discrepancies may represent different biologic adaptations to distinct metabolic diseases. METHODS: We conducted a comprehensive review of English language citations in Pubmed and Embase using the keywords "diabetes", "placenta", AND "pathology". Abstracts were reviewed for relevance then full-text articles were reviewed in order to extract a comprehensive summary of current pathological findings associated with pregestational and gestational diabetes mellitus, as well as an understanding of the impact of glycemic control on placental pathology. RESULTS: Placental abnormalities most consistently associated with maternal diabetes are an increased incidence of villous immaturity, increased measures of angiogenesis, and increased placental weight. CONCLUSIONS: The literature suggests that, despite similarities in placental abnormalities, differences in placental pathology may reflect differences in pathophysiology among different types of diabetes. Consequently, standardization of terminology used to define placental lesions is warranted. Moreover, further research is needed to investigate the impact of pathophysiology, glycemic control and clinical factors, such as infant sex, weight and race, on placental structure and function.

Sebotropic eruption associated with use of oral kava kava supplement.

Supplement use is prevalent, and its use is increasing among older adults. Dermatologists need to be aware of the adverse cutaneous effects that can result from herbal supplement use. A 55-year-old man presented with an eruption in a sebotropic distribution after consuming kava kava for 3 weeks, which resolved after discontinuation of the supplement. This case highlights the need for clinicians to consider kava kava in the differential of sebotropic eruptions. The biology, mechanism of action, and potential systemic and cutaneous effects of kava kava are reviewed.

History of chronic comorbidity and risk of chemotherapy-induced febrile neutropenia in cancer patients not receiving G-CSF prophylaxis.

BACKGROUND: Chemotherapy-induced febrile neutropenia (FN) is a clinically important complication that affects patient outcome by delaying chemotherapy doses or reducing dose intensity. Risk of FN depends on chemotherapy- and patient-level factors. We sought to determine the effects of chronic comorbidities on risk of FN. DESIGN: We conducted a cohort study to examine the association between a variety of chronic comorbidities and risk of FN in patients diagnosed with six types of cancer (non-Hodgkin lymphoma and breast, colorectal, lung, ovary, and gastric cancer) from 2000 to 2009 who were treated with chemotherapy at Kaiser Permanente Southern California, a large managed care organization. We excluded those patients who received primary prophylactic granulocyte colony-stimulating factor. History of comorbidities and FN events were identified using electronic medical records. Cox models adjusting for propensity score, stratified by cancer type, were used to determine the association between comorbid conditions and FN. Models that additionally adjusted for cancer stage, baseline neutrophil count, chemotherapy regimen, and dose reduction were also evaluated. RESULTS: A total of 19 160 patients with mean age of 60 years were included; 963 (5.0%) developed FN in the first chemotherapy cycle. Chronic obstructive pulmonary disease [hazard ratio (HR) = 1.30 (1.07-1.57)], congestive heart failure [HR = 1.43 (1.00-1.98)], HIV infection [HR = 3.40 (1.90-5.63)], autoimmune disease [HR = 2.01 (1.10-3.33)], peptic ulcer disease [HR = 1.57 (1.05-2.26)], renal disease [HR = 1.60 (1.21-2.09)], and thyroid disorder [HR = 1.32 (1.06-1.64)] were all associated with a significantly increased FN risk. CONCLUSIONS: These results provide evidence that history of several chronic comorbidities increases risk of FN, which should be considered when managing patients during chemotherapy.

Metabolomic Analysis Reveals Amino Acid Responses to an Oral Glucose Tolerance Test in Women with Prior History of Gestational Diabetes Mellitus.

OBJECTIVE: Although gestational diabetes mellitus (GDM) is associated with an increased risk of type 2 diabetes mellitus (T2DM) compared to normoglycemic pregnancies, the biochemical pathways underlying the progression of GDM to T2DM are not fully elucidated. The purpose of this exploratory study was to utilize metabolomics with an oral glucose tolerance test (OGTT) to examine the amino acid response in women with prior GDM to determine if a relationship between these metabolites and established risk factors for T2DM exists. MATERIALS/METHODS: Thirty-eight non-pregnant women without diabetes but with prior GDM within the previous 3 years were recruited from a community-based population. A 75 g-OGTT was administered; fasting and 2-hr plasma samples were obtained. Metabolite profiles of 23 amino acids or amino acid derivatives were measured with gas chromatography-mass spectrometry. Measures of insulin resistance were derived from the OGTT and risk factors for T2DM were obtained by self-report. RESULTS: Twenty-two metabolite levels decreased significantly in response to the OGTT (p<0.05). The clinical covariates most powerfully associated with metabolite level changes included race, body mass index (BMI), and duration of prior breastfeeding, (mean ± SD of standardized ß-coefficients, ß = -0.38 ± 0.05, 0.25 ± 0.08, and 0.44 ± 0.03, respectively, all p<0.05). Notably, a prior history of breastfeeding was associated with the greatest number of metabolite changes. CONCLUSIONS: Greater change in metabolite levels after a glucose challenge was significantly associated with a longer duration of breastfeeding and higher BMI. Further exploration of these preliminary observations and closer examination of the specific pathways implicated are warranted.

Regulation of Nuclear Import During Differentiation; The IMP alpha Gene Family and Spermatogenesis.

Access to nuclear genes in eukaryotes is provided by members of the importin (IMP) superfamily of proteins, which are of alpha- or beta-types, the best understood nuclear import pathway being mediated by a heterodimer of an IMP alpha and IMP beta1. IMP alpha recognises specific targeting signals on cargo proteins, while IMP beta1 mediates passage into, and release within, the nucleus by interacting with other components of the transport machinery, including the monomeric guanine nucleotide binding protein Ran. In this manner, hundreds of different proteins can be targeted specifically into the nucleus in a tightly regulated fashion. The IMP alpha gene family has expanded during evolution, with only a single IMP alpha (Srp1p) gene in budding yeast, and three (IMP alpha1, 2/pendulin and 3) and five (IMP alpha1, -2, -3, -4 and -6) IMP alpha genes in Drosophila melanogaster and mouse respectively, which fall into three phylogenetically distinct groups. The fact that IMP alpha3 and IMP alpha2 are only present in metazoans implies that they emerged during the evolution of multicellular animals to perform specialised roles in particular cells and tissues. This review describes what is known of the IMP alpha gene family in mouse and in D. melanogaster, including a comparitive examination of their mRNA expression profiles in a highly differentiated tissue, the testis. The clear implication of their highly regulated synthesis during the course of spermatogenesis is that the different IMP alphas have distinct expression patterns during cellular differentiation, implying tissue/cell type-specific roles.

Bazooka and PAR-6 are required with PAR-1 for the maintenance of oocyte fate in Drosophila.

The anterior-posterior axis of C. elegans is defined by the asymmetric division of the one-cell zygote, and this is controlled by the PAR proteins, including PAR-3 and PAR-6, which form a complex at the anterior of the cell, and PAR-1, which localizes at the posterior [1-4]. PAR-1 plays a similar role in axis formation in Drosophila: the protein localizes to the posterior of the oocyte and is necessary for the localization of the posterior and germline determinants [5, 6]. PAR-1 has recently been shown to have an earlier function in oogenesis, where it is required for the maintenance of oocyte fate and the posterior localization of oocyte-specific markers [7, 8]. Here, we show that the homologs of PAR-3 (Bazooka) and PAR-6 are also required to maintain oocyte fate. Germline clones of mutants in either gene give rise to egg chambers that develop 16 nurse cells and no oocyte. Furthermore, oocyte-specific factors, such as Orb protein and the centrosomes, still localize to one cell but fail to move from the anterior to the posterior cortex. Thus, PAR-1, Bazooka, and PAR-6 are required for the earliest polarity in the oocyte, providing the first example in Drosophila where the three homologs function in the same process. Although these PAR proteins therefore seem to play a conserved role in early anterior-posterior polarity in C. elegans and Drosophila, the relationships between them are different, as the localization of PAR-1 does not require Bazooka or PAR-6 in Drosophila, as it does in the worm.

Centrosome migration into the Drosophila oocyte is independent of BicD and egl, and of the organisation of the microtubule cytoskeleton.

During early Drosophila oogenesis, one cell from a cyst of 16 germ cells is selected to become the oocyte, and accumulates oocyte-specific proteins and the centrosomes from the other 15 cells. Here we show that the microtubule cytoskeleton and the centrosomes follow the same stepwise restriction to one cell as other oocyte markers. Surprisingly, the centrosomes still localise to one cell after colcemid treatment, and in BicD and egl mutants, which abolish the localisation of all other oocyte markers and the polarisation of the microtubule cytoskeleton. In contrast, the centrosomes fail to migrate in cysts mutant for Dynein heavy chain 64C, which disrupts the fusome. Thus, centrosome migration is independent of the organisation of the microtubule cytoskeleton, and seems to depend instead on the polarity of the fusome.

PAR-1 is required for the maintenance of oocyte fate in Drosophila.

The PAR-1 kinase is required for the posterior localisation of the germline determinants in C. elegans and Drosophila, and localises to the posterior of the zygote and the oocyte in each case. We show that Drosophila PAR-1 is also required much earlier in oogenesis for the selection of one cell in a germline cyst to become the oocyte. Although the initial steps in oocyte determination are delayed, three markers for oocyte identity, the synaptonemal complex, the centrosomes and Orb protein, still become restricted to one cell in mutant clones. However, the centrosomes and Orb protein fail to translocate from the anterior to the posterior cortex of the presumptive oocyte in region 3 of the germarium, and the cell exits meiosis and becomes a nurse cell. Furthermore, markers for the minus ends of the microtubules also fail to move from the anterior to the posterior of the oocyte in mutant clones. Thus, PAR-1 is required for the maintenance of oocyte identity, and plays a role in microtubule-dependent localisation within the oocyte at two stages of oogenesis. Finally, we show that PAR-1 localises on the fusome, and provides a link between the asymmetry of the fusome and the selection of the oocyte.

A DNA vaccine encoding a conserved Eimeria protein induces protective immunity against live Eimeria acervulina challenge.

Coccidiosis is caused by several distinct intestinal protozoa of Eimeria sp., and is responsible for intestinal lesions and severe body weight loss in chickens. To develop a DNA vaccination strategy for coccidiosis, an expression vector pMP13 encoding a conserved antigen of Eimeria was constructed by subcloning 3-1E cDNA into pBK-CMV and used to elicit protective immunity against E. acervulina. One-day-old chickens were immunized intramuscularly (IM) or subcutaneously (SC) with various doses of pMP13 expression vector ranging from 5 to 100 ug two weeks apart and were challenged with 5x10(3) E. acervulina. Chickens immunized with 5, 10, 50 or 100 ug of pMP13 plasmid, but not control plasmid, pBK-CMV, showed significantly reduced oocysts following challenge infection with E. acervulina. Two injections were in general more effective than one injection with higher dose of DNA eliciting better protection. At 10 days post challenge infection, maximum levels of circulating antibodies were detected regardless of the routes of injection, although IM injection provided higher levels of serum antibodies compared to SC injection. Serum antibody levels demonstrated a dose-dependent response showing higher antibody production at higher DNA dose. DNA immunization with pMP13 also induced significant changes in T-cell subpopulations in the spleen and duodenum intraepithelial lymphocytes. At 4 days post DNA immunization, pMP13-immunized chickens showed lower CD8, and higher CD4(+) and gammadelta T(+) cells in the duodenum compared to the pBK-CMV-immunized chickens. Following challenge infection with E. acervulina, pMP13-immunized chickens showed lower CD8(+) and alphabeta T(+) cells, and higher CD4(+) cells than pBK-CMV-immunized chickens in the duodenum. These findings demonstrate that DNA immunization with pMP13 induce local and systemic host immune responses against Eimeria.

The role of BicD, Egl, Orb and the microtubules in the restriction of meiosis to the Drosophila oocyte.

The oocyte is the only cell in Drosophila that goes through meiosis with meiotic recombination, but several germ cells in a 16-cell cyst enter meiosis and form synaptonemal complexes (SC) before one cell is selected to become the oocyte. Using an antibody that recognises a component of the SC or the synapsed chromosomes, we have analysed how meiosis becomes restricted to one cell, in relation to the other events in oocyte determination. Although BicD and egl mutants both cause the development of cysts with no oocyte, they have opposite effects on the behaviour of the SC: none of the cells in the cyst form SC in BicD null mutants, whereas all of the cells do in egl and orb mutants. Furthermore, unlike all cytoplasmic markers for the oocyte, the SC still becomes restricted to one cell when the microtubules are depolymerised, even though the BicD/Egl complex is not localised. These results lead us to propose a model in which BicD, Egl and Orb control entry into meiosis by regulating translation.

Prevalence of gestational diabetes mellitus among Swampy Cree women in Moose Factory, James Bay.

BACKGROUND: Although high rates of gestational diabetes mellitus have been documented in native populations, few studies have examined rates of the disease among native Indians in Canada. The authors conducted a study to estimate the prevalence of gestational diabetes among Swampy Cree women, to identify factors predictive of the occurrence of gestational diabetes, and to identify delivery and infant outcomes related to the presence of the disease. METHODS: Information on Swampy Cree women who gave birth at Weeneebayko Hospital, Moose Factory, James Bay, Ont., between 1987 and 1995 was obtained from medical charts. Patients with and without gestational diabetes were compared. Logistic regression analysis was used to identify independent predictors of gestational diabetes. Delivery and infant outcomes that occurred secondary to gestational diabetes were also identified by means of logistic regression. RESULTS: A total of 1401 deliveries occurred at Weeneebayko Hospital over the study period, of which 1298 were included in the study. Gestational diabetes was diagnosed in 110 (8.5% [95% confidence interval (CI) 6.9%-9.9%]) of the 1298 pregnancies. Factors predictive of gestational diabetes were age 35 years or more (relative risk [RR] 4.1, 95% CI 1.5-11.7), a history of gestational diabetes in a previous pregnancy (RR 6.4, 95% CI 3.5-11.7), diastolic blood pressure of 80 mm Hg or higher at the first prenatal visit (RR 1.7, 95% CI 1.1-2.8), weight greater than 80 kg at the first prenatal visit (RR 4.9, 95% CI 1.8-12.9) and having a first-degree relative with diabetes (RR 3.0, 95% CI 1.4-6.1). The only delivery outcome independently associated with the presence of gestational diabetes was an increased likelihood of needing assisted delivery (forceps or vacuum extraction) (RR 2.8, 95% CI 1.1-7.0). Shoulder dystocia was indirectly associated with gestational diabetes owing to increased infant birth weight. Infant outcomes associated with the presence of gestational diabetes were birth weight greater than 4500 g (RR 2.4, 95% CI 1.4-3.8), hyperbilirubinemia (RR 2.9, 95% CI 1.4-6.1), hypoglycemia (RR 7.3, 95% CI 3.7-14.4) and hypocalcemia (RR 8.9, 95% CI 2.3-33.7). INTERPRETATION: Gestational diabetes occurred in a significant minority of Swampy Cree women and was associated with a number of adverse outcomes.

The role of the non-conserved residue at position 104 of class A beta-lactamases in susceptibility to mechanism-based inhibitors.

The role of the non-conserved amino acid residue at position 104 of the class A beta-lactamases, which comprises a highly conserved sequence of amino acids at the active sites of these enzymes, in both the hydrolysis of beta-lactam substrates and inactivation by mechanism-based inhibitors was investigated. Site-directed mutagenesis was performed on the penPC gene encoding the Bacillus cereus 569/H beta-lactamase I to replace Asp104 with the corresponding Staphylococcus aureus PC1 residue Ala104. Kinetic data obtained with the purified Asp104Ala B. cereus 569/H beta-lactamase I was compared to that obtained from the wild-type B. cereus and S. aureus enzymes. Replacement of amino acid residue 104 had little effect on the Michaelis parameters for the hydrolysis of both S- and A-type penicillins. Relative to wild-type enzyme, the Asp104Ala beta-lactamase I had 2-fold higher Km values for benzylpenicillin and methicillin, but negligible difference in Km for ampicillin and oxacillin. However, kcat values were also slightly increased resulting in little change in catalytic efficiency, kcat/Km. In contrast, the Asp104Ala beta-lactamase I became more like the S. aureus enzyme in its response to the mechanism-based inhibitors clavulanic acid and 6-beta-(trifluoromethane sulfonyl)amido-penicillanic acid sulfone with respect to both response to the inhibitors and subsequent enzymatic properties. Based on the known three-dimensional structures of the Bacillus licheniformis 749/C, Escherichia coli TEM and S. aureus PC1 beta-lactamases, a model for the role of the non-conserved residue at position 104 in the process of inactivation by mechanism-based inhibitors is proposed.

Fulminant hepatic failure post liver transplantation: clinical syndromes, correlations and outcomes.

This paper reports the clinical syndrome of fulminant hepatic failure (FHF) following liver transplantation. FHF was defined as the sudden onset of liver failure [encephalopathy and prolonged International Normalised Ratio (INR)] without arterial thrombosis in the setting of a liver allograft. FHf post-transplant was seen in 8/154 (5.2%) adult patients undergoing transplantation. These eight patients developed a clinical syndrome characterised by: (a) a rapid rise in ALT levels to above 1000 U/l (mean maximum 1600 U/l), (b) a sudden increase in the INR to above 5 (mean maximum 5.6), (c) the development of high fever, (d) the persistence of thrombocytopenia (mean nadir 40 x 10(9)/dl), (e) a progressive rise in the bilirubin (mean maximum 400 mumol/l) and (f) the development of hepatic encephalopathy. In seven cases this syndrome occurred following good initial graft function at day 6 post (mean)-transplant. In one case the above syndrome developed immediately after liver transplantation. Four of the eight patients developed multiorgan failure associated with systemic acidosis (mean pH 6.84). All of these patients died (mean day 11). Four patients developed systemic alkalosis. Two of these four patients underwent successful retransplantation (on days 12 and 13) and remain alive at a mean of 11 months post-transplant. Six of the eight patients received OKT3 therapy without any apparent affect on clinical outcome. Compared to control group of patients (n = 28), 8 versus 2/28 had a positive cross-match with donor lymphocytes (P = NS), 1/8 versus 7/28 were ABO-non-identical (P = NS), 3/8 versus 10/21 had total MHC mismatches (P = NS) and 5/7 versus 6/16 had UW ischemic times above 10 h (P = NS). No patients had main hepatic artery thrombosis on angiography although four patients had evidence of intrahepatic microthrombi or arterial necrosis at autopsy. In all cases the histology showed massive haemorrhagic necrosis. Three cases had evidence of veno-occlusive lesions whilst foam cell arteriopathy was seen in two cases. Immunofluorescence was performed in three cases. In two cases there was evidence of immunoglobulin, complement and fibrin deposition in blood vessels. In conclusion, we describe an uncommon clinical syndrome occurring post liver transplant. This syndrome represents humorally mediated allograft rejection but there seems to be no relationship with tissue matching (antibody, ABO, MHC) or donor ischaemic times. If recognised earlier in the absence of multiorgan failure, urgent retransplantation seems to be the only effective therapy.