Men in committed, romantic relationships have lower testosterone

Variation in human male testosterone levels may reflect, and effect, differential behavioral allocation to mating and parenting effort. This proposition leads to the hypothesis that, among North American men, those involved in committed, romantic relationships will have lower testosterone levels than men not involved in such relationships. Our study is the first to examine whether being in such a relationship (rather than being married) is the meaningful predictor of male testosterone levels. To test this hypothesis, 122 male Harvard Business School students filled out a questionnaire and collected one saliva sample (from which testosterone level was measured). Results revealed that men in committed, romantic relationships had 21% lower testosterone levels than men not involved in such relationships. Furthermore, the testosterone levels of married men and unmarried men who were involved in committed, romantic relationships did not differ, suggesting that, at least for this sample, male pair bonding status is the more significant predictor of testosterone levels than is marital status.     

Enhancement of 3H-phenytoin binding by diazepam and (+)bicuculline

3H-Phenytoin binding to the particulate fraction of rat wholebrain homogenate was studied using the filter assay technique. It was found that diazepam and (+)bicuculline methobromide caused a concentration-dependent enhancement of the total binding of 3H-phenytoin, whereas GABA and (-)bicuculline methobromide (the inactive bicuculline isomer) had no effect. In subsequent competition experiments (labelled versus unlabelled phenytoin), it was found that the presence of a potentiating concentration of diazepam transformed the biphasic phenytoin competition isotherm into a simple curve with a Hill coefficient of approximately one, and a Ki of 110 nM.     

Limits in virus filtration capability? Impact of virus quality and spike level on virus removal with xenotropic murine leukemia virus

Virus filtration (VF) is a key step in an overall viral clearance process since it has been demonstrated to effectively clear a wide range of mammalian viruses with a log reduction value (LRV) > 4. The potential to achieve higher LRV from virus retentive filters has historically been examined using bacteriophage surrogates, which commonly demonstrated a potential of > 9 LRV when using high titer spikes (e.g. 10¹⁰ PFU/mL). However, as the filter loading increases, one typically experiences significant decreases in performance and LRV. The 9 LRV value is markedly higher than the current expected range of 4‐5 LRV when utilizing mammalian retroviruses on virus removal filters (Miesegaes et al., Dev Biol (Basel) 2010;133:3‐101). Recent values have been reported in the literature (Stuckey et al., Biotech Progr 2014;30:79‐85) of LRV in excess of 6 for PPV and XMuLV although this result appears to be atypical. LRV for VF with therapeutic proteins could be limited by several factors including process limits (flux decay, load matrix), virus spike level and the analytical methods used for virus detection (i.e. the Limits of Quantitation), as well as the virus spike quality. Research was conducted using the Xenotropic‐Murine Leukemia Virus (XMuLV) for its direct relevance to the most commonly cited document, the International Conference of Harmonization (ICH) Q5A (International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, Geneva, Switzerland, 1999) for viral safety evaluations. A unique aspect of this work is the independent evaluation of the impact of retrovirus quality and virus spike level on VF performance and LRV. The VF studies used XMuLV preparations purified by either ultracentrifugation (Ultra 1) or by chromatographic processes that yielded a more highly purified virus stock (Ultra 2). Two monoclonal antibodies (Mabs) with markedly different filtration characteristics and with similar levels of aggregate (<1.5%) were evaluated with the Ultra 1 and Ultra 2 virus preparations utilizing the Planova 20 N, a small virus removal filter. Impurities in the virus preparation ultimately limited filter loading as measured by determining the volumetric loading condition where 75% flux decay is observed versus initial conditions (V₇₅). This observation occurred with both Mabs with the difference in virus purity more pronounced when very high spike levels were used (>5 vol/vol %). Significant differences were seen for the process performance over a number of lots of the less‐pure Ultra 1 virus preparations. Experiments utilizing a developmental lot of the chromatographic purified XMuLV (Ultra 2 Development lot) that had elevated levels of host cell residuals (vs. the final Ultra 2 preparations) suggest that these contaminant residuals can impact virus filter fouling, even if the virus prep is essentially monodisperse. Process studies utilizing an Ultra 2 virus with substantially less host cell residuals and highly monodispersed virus particles demonstrated superior performance and an LRV in excess of 7.7 log₁₀. A model was constructed demonstrating the linear dependence of filtration flux versus filter loading which can be used to predict the V₇₅ for a range of virus spike levels conditions using this highly purified virus. Fine tuning the virus spike level with this model can ultimately maximize the LRV for the virus filter step, essentially adding the LRV equivalent of another process step (i.e. protein A or CEX chromatography). © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:135–144, 2015     

Using indirect methods to understand the impact of forced migration on long-term under-five mortality

Despite the large numbers of displaced persons and the often-lengthy periods of displacement, little is known about the impact of forced migration on long-term under-five mortality. This paper looks at the Brass Method (and adaptations of this method) and the Preceding Birth Technique in combination with a classification of women by their migration and reproductive histories, in order to study the impact of forced migration on under-five mortality. Data came from the Demography of Forced Migration Project, a study on mortality, fertility and violence in the refugee and host populations of Arua District, Uganda and Yei River District, Sudan. Results indicate that women who did not migrate in a situation of conflict and women who repatriated before the age of 15, had children with the highest under-five mortality rates compared with women who were currently refugees and women who repatriated after the age of 15.     

Functional differences in human neutrophils isolated pre- and post-prandially.

Activated polymorphonuclear leukocytes have been associated with neoplasia, atherogenesis and reperfusion injury. Since some of these conditions are also correlated with dietary fat, we examined the functional characteristics of leukocytes isolated from subjects before and after consumption of a lipid-rich meal. There was up to 2-fold greater superoxide generation in response to agonists in leukocytes obtained post-prandially; the maximum increase was observed about 4 h after eating and followed the peak (2-4 h) in serum triglycerides. Neutrophils isolated post-prandially also exhibited impaired chemotaxis and defective bacterial killing, but normal phagocytosis. These findings provide a new variable that should be considered in studies of leukocytes.     

Cyclic AMP-elevating agents block chemoattractant activation of diradylglycerol generation by inhibiting phospholipase D activation.

Agents which elevate cellular cAMP (prostaglandin E2, theophylline, and forskolin) or mimic cAMP action (dibutyryl cAMP) are known to inhibit human neutrophil activation (superoxide generation and secretion) by receptor-linked agonists such as formyl-methionyl-leucyl-phenylalanine (fMLP). Herein, we show that these agents also markedly inhibit fMLP-stimulated diradylglycerol generation (assayed by mass methods). The magnitude of inhibition correlated with the ability of a given agent or combination of agents to elevate cAMP. Both 1,2-diacylglycerol and 1-O-alkyl,2-acyl glycerol generation were affected. Effects on the latter species, as well as a lack of effect on fMLP-stimulated inositol phosphate release, implied that cAMP affected diradylglycerol generation from a source other than phospholipase C-dependent phosphoinositide hydrolysis, since phosphatidylinositols do not contain appreciable quantities of the 1-O-alkyl linkage. In cells in which the phosphatidylcholine pool was prelabeled using 1-O-[3H]octadecyl-2-lyso-sn-glycero-3-phosphocholine, prostaglandin E2 plus theophylline inhibited the fMLP-activated rapid generation of [3H]phosphatidic acid and its subsequent conversion to [3H]diradylglycerol, implying an effect at the level of phospholipase D. In the presence of ethanol, the fMLP-activated transphosphatidylation of [3H]phosphatidylcholine to generate [3H]phosphatidylethanol (a phospholipase D-dependent reaction) was also markedly inhibited. In contrast, when phorbol 12-myristate 13-acetate was used to activate cells, cAMP-related agents had no effect on phospholipase D activity, diradylglycerol generation, or superoxide generation. The data indicate an inhibitory effect of cyclic AMP on receptor-mediated phospholipase D activation at a site proximal to phospholipase D (e.g., the receptor or G protein). These studies provide a new example of "cross-talk" among signal transduction systems.     

ANABOLIC RESPONSES OF EMBRYONIC DORSAL ROOT GANGLIA TO NERVE GROWTH FACTOR, INSULIN, CONCANAVALIN A OR SERUM IN VITRO

—Intact and dissociated dorsal root ganglia from 8-day chick embryos were examined for their ability to incorporate radio-precursors into RNA and protein in unsupplemented medium or in medium supplemented with Nerve Growth Factor, insulin, Concanavalin A, fetal calf serum, or several combinations of such agents. In the absence of any agent, incorporation into RNA and protein declined with time. All four agents maintained or improved the initial incorporation rates, and optimal doses were determined in each case. Different combinations of two agents led to potentiated, full or partially additive, or inhibited effects; in particular, NGF promoted incorporation even in conjunction with insulin (additive) or serum (potentiating). Several differences were noted between the responses of intact and of dissociated ganglia.     

EXTRACELLULAR LYSIS OF THE BLUEGREEN ALGA PHORMIDIUM LURIDUM BY BDELLOVIBRIO BACTERIOVORUS1

When either cells of the bacterium, Bdellovibrio bacteriovorus (Stolp & Starr), strain 15143, or a heat-resistant lytic factor derived from these cells is added to viable cultures of Phormidium luridum var. olivacea Boresch all the algal cells underwent gradual lysis. This effect was obtained with a mean initial bdellovibrio:algal cell ratio of 7.5:1. When P. luridum was mixed with the bdellovibrio cultures the algal chlorophyll content showed an 8-fold decrease. Concomitantly, this interspecies interaction caused, a 75% inhibition of algal photosynthesis after-4 h. Heat, treatment of the B. bacteriovorus culture supernatant fluid increased its ability to inhibit photosynthesis approximately 14%. Light, microscopy showed pale granules and intracellular spaces to form in the P. luridum within 16 h after adding the bdellovibrio lytic factor. Subsequent morphological changes included the development of large intracellular spaces, intercellular spaces, spheroplast formation and finally Complete lysis of the algal cells.     

ELECTRON MICROSCOPE OBSERVATIONS ON THE INTERACTION OF BDELLOVIBRIO BACTERIOVORUS WITH PHORMIDIUM LURIDUM AND SYNECHOCOCCUS SP. (CYANOPHYCEAE)1

The effects of Bdellovibrio bacteriovorus (Stolp & Starr) culture supernatants on Phormidium luridum var. olivacea Boresch and Synechococcus sp. were examined by transmission electron microscopy. Both normal (nonheat-treated) and heat-treated bdellovibrio supernatant caused the formation of intrathylakoidal vesicles in P. luridum in 24–48 h. This vesiculation increased until 96–129 h when the P. luridum showed loss of the mucopeptide layer in the cell envelope and subsequently lysed. Similar treatment of Synechococcus sp. with the bdellovibrio supernatants showed a different ultrastructural pattern with the apparent dissolution of many of the photosynthetic membranes in the bluegreen cells. Myelin-like membranous configurations were seen in some of these treated cells. The results suggest that an autolytic mechanism in P. luridum and Synechococcus sp. is stimulated by the bdellovibrio secretions.