Can Dreams During Pregnancy Predict Postpartum Depression?

Postpartum depression (henceforth PPD) is an emotional disturbance which occurs in as much as 20% of the childbearing population. This study attempted to ascertain whether dreams, offering unconscious expression of internal emotional processes, could help to identify early signs of PPD. It was hypothesized that differences would be found in the emotional dream work of pregnant women who either later developed or did not develop PPD. 166 women participated in the two stages of the study. During stage I, the women were interviewed in the last trimester of their first pregnancies. The interview included a demographic questionnaire and an account of a dream. During stage II, the women were interviewed 6–10 weeks after giving birth. The second interview included only the EPDS scale for affirming or denying the occurrence of PPD. The findings of the study confirm the hypothesis that dreams of pregnant women can differentiate among women who are or are not at-risk for PPD. It was found that more unpleasant dreams and dreams expressing apprehension were found among women who did not later develop PPD, than among women who did develop PPD.     

DAP kinase and DRP-1 mediate membrane blebbing and the formation of autophagic vesicles during programmed cell death

Death-associated protein kinase (DAPk) and DAPk-related protein kinase (DRP)-1 proteins are Ca+2/calmodulin-regulated Ser/Thr death kinases whose precise roles in programmed cell death are still mostly unknown. In this study, we dissected the subcellular events in which these kinases are involved during cell death. Expression of each of these DAPk subfamily members in their activated forms triggered two major cytoplasmic events: membrane blebbing, characteristic of several types of cell death, and extensive autophagy, which is typical of autophagic (type II) programmed cell death. These two different cellular outcomes were totally independent of caspase activity. It was also found that dominant negative mutants of DAPk or DRP-1 reduced membrane blebbing during the p55/tumor necrosis factor receptor 1-induced type I apoptosis but did not prevent nuclear fragmentation. In addition, expression of the dominant negative mutant of DRP-1 or of DAPk antisense mRNA reduced autophagy induced by antiestrogens, amino acid starvation, or administration of interferon-gamma. Thus, both endogenous DAPk and DRP-1 possess rate-limiting functions in these two distinct cytoplasmic events. Finally, immunogold staining showed that DRP-1 is localized inside the autophagic vesicles, suggesting a direct involvement of this kinase in the process of autophagy.     

The regulation of death-associated protein (DAP) kinase in apoptosis

DAP-kinase is a calcium/calmodulin (Ca2+/CaM) serine/threonine kinase which positively mediates programmed cell death in a variety of cell systems. The kinase is localized to the actin microfilament and has a unique, multidomain structure consisting of ankyrin repeats and a death domain. One of the substrates of DAP-kinase was identified as myosin light chain (MLC), the phosphorylation of which mediates membrane blebbing. Another arm in its mode of action leads to the formation of autophagic vesicles. Recent work addressed its mode of regulation and identified a mechanism which restrains its apoptotic function in growing cells and enables its activation during cell death. It involves an inhibitory type of autophosphorylation on serine 308 within the CaM regulatory domain. This negative phosphorylation takes place in growing cells and is strongly reduced upon their exposure to the apoptotic stimulus of C6-ceramide. The substitution of serine 308 to alanine, which mimics the ceramide-induced dephosphorylation at this site, increases Ca2+/CaM-independent substrate phosphorylation, as well as binding and overall sensitivity of the kinase to CaM. At the cellular level, it strongly enhances the death-promoting activity of the kinase. These results are consistent with a molecular model in which phosphorylation on serine 308 stabilizes a locked conformation of the CaM regulatory domain within the catalytic cleft and, simultaneously, also interferes with CaM binding. We propose that this unique mechanism of auto-inhibition evolved to impose a locking device which keeps DAP-kinase silent in healthy cells and ensures its activation only in response to apoptotic signals.     

Amphiphilic block copolymers as bile acid sorbents: 1. Synthesis of polystyrene-b-poly(N,N,N-trimethylammoniumethylene acrylamide chloride)

The systematic investigation of the synthesis of polystyrene-b-poly(N,N,N-trimethylammoniumethylene acrylamide chloride) was accomplished by employing both polystyrene-b-poly(tert-butyl acrylate) and its hydrolyzed derivative, polystyrene-b-poly(acrylic acid) (PS-b-PAA) as starting materials, and coupling them with N,N-dimethylethylenediamine (DMED). The various reactions and intermediates we examined include aluminum amides, acid chlorides, and imides derived from carbodiimides, all in a variety of solvents. We present below our investigation of several synthetic routes and conclude that the carbodiimide coupling of PS-b-PAA with DMED followed by quaternization and counterion exchange is the most effective method of achieving the target. A brief discussion of the merits of each procedure in the context of block copolymers is given, and IR spectroscopic evidence for the postpolymerization synthesis of the poly(acrylamide) block is provided.     

Simultaneous effect of calcium,magnesium, copper and cobalt ions on sapogenin steroids content in callus cultures of Agave amaniensis

The simultaneous effect of calcium, cobalt, copper and magnesium ions and their interactions on growth and sapogenin steroids accumulation in callus cultures of Agave amaniensis was studied by using a central composite second-order rotatable design. The absence of calcium ions in media increased the sapogenin steroid content, while relatively high concentration of magnesium, cobalt and copper ions simultaneously inhibited the sapogenin steroid formation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Frequency dependence and stability

The use of difference equations is suggested for simulating frequency-dependent changes in gene frequencies. Our model shows a good fit to published cases of populations in which gene frequencies reached stable equilibrium. However, in the same deterministic model, slight changes in the value of some parameters can lead to cyclic or chaotic behavior.     

Approaches to the reintroduction of the Bali mynah

The Bali mynah (Leucopsar rothschildi) is an endangered bird endemic to the island of Bali, Indonesia. The wild population of approximately 17 birds is confined to West Bali National Park (Taman Nasional Bali Barat). The species was intensively collected for the bird trade in the 1960s and 1970s, and poaching for the internal trade in Indonesia remains the primary threat to the wild population. We conducted an experimental release of one captive-bred and five confiscated, wild origin Bali mynahs on the small offshore island Pulau Menjangan. Released birds readily developed flight and foraging skills. Of the six, radio-tagged birds released, one was stolen, three were likely killed by a raptor, and two were returned successfully to the wild. Many challenges remain for the conservation of this species, including poaching in the national park, disease in the captive population, predation by raptors on newly released birds, and destruction of essential habitat. Results suggest that the Bali mynah is a suitable species for an expanded propagation and release program, provided that poaching is curtailed and disease in birds intended for release can be eliminated. Zoo Biol 17:267–284, 1998. © 1998 Wiley-Liss, Inc.     

A protease-activatable luminescent biosensor and reporter cell line for authentic SARS-CoV-2 infection

Efforts to define serological correlates of protection against COVID-19 have been hampered by the lack of a simple, scalable, standardised assay for SARS-CoV-2 infection and antibody neutralisation. Plaque assays remain the gold standard, but are impractical for high-throughput screening. In this study, we show that expression of viral proteases may be used to quantitate infected cells. Our assays exploit the cleavage of specific oligopeptide linkers, leading to the activation of cell-based optical biosensors. First, we characterise these biosensors using recombinant SARS-CoV-2 proteases. Next, we confirm their ability to detect viral protease expression during replication of authentic virus. Finally, we generate reporter cells stably expressing an optimised luciferase-based biosensor, enabling viral infection to be measured within 24 h in a 96- or 384-well plate format, including variants of concern. We have therefore developed a luminescent SARS-CoV-2 reporter cell line, and demonstrated its utility for the relative quantitation of infectious virus and titration of neutralising antibodies.