Variants in AQP11 may result in autosomal recessive bilateral cystic renal dysgenesis

Congenital renal cystic dysplasia is a rare disease that occurs in approximately 1 in 4000 children and is often discovered in the antenatal period by ultrasound. It is commonly associated with oligohydramnios in utero and/or renal insufficiency or failure in the postnatal period. Aquaporins are membrane proteins that serve as transport channels in the transfer of water or small solutes across cell membranes. They play a role in the development of renal cysts. Aquaporin 11 (AQP11) deficient mice develop polycystic kidney disease in utero due to disruption of polycystin-1. Here we describe a case of bilateral cystic kidney disease in a patient with novel compound heterozygous variants in AQP11: c.780G>T (p. Trp260Cys) and c.472C>T (p.Pro158Ser) (NM_173039.2) identified by whole genome sequencing. These findings suggest, for the first time, the potential role of AQP11 in congenital renal cystic dysplasia.

Pediatric COVID-19 Involving Complicated Sinusitis With Intracranial Extension and Lemierre Syndrome: A Case Report

Pediatric coronavirus disease 2019 (COVID-19) has been associated with various complications including chronic respiratory disease and multisystem inflammatory syndrome. There are a few reported cases of complicated sinusitis following pediatric COVID-19 infection. We present a patient with recent COVID-19 who developed complicated sinusitis with intracranial extension and Lemierre syndrome. A 16-year-old female with a history of COVID-19 diagnosis 17 days prior presented with worsening head and neck symptoms. Physical examination demonstrated left proptosis, cranial nerve (CN) VI palsy, and limited neck range of motion. Imaging demonstrated bilateral sinus disease, a 3.3 × 2 × 3-centimeter sellar/clival abscess, bilateral cavernous sinus thrombosis, and thrombosis of bilateral internal jugular veins. Urgent endoscopic sinus surgery was performed, and long-term intravenous antibiotics and anticoagulation were initiated with improvement in symptoms over three weeks. Providers caring for patients with COVID-19 should keep complicated sinusitis and Lemierre syndrome in their differential. Further study of COVID-19 pathophysiology in the sinonasal mucosa is needed.

Loss of cAMP-dependent stimulation of isolated cilia motility by alcohol exposure is oxidant-dependent

Alcohol exposure is associated with decreased mucociliary clearance, a key innate defense essential to lung immunity. Previously, we identified that prolonged alcohol exposure results in dysfunction of airway cilia that persists at the organelle level. This dysfunction is characterized by a loss of 3',5'-cyclic adenosine monophosphate (cAMP)-mediated cilia stimulation. However, whether or not ciliary dysfunction develops intrinsically at the organelle level has not been explored. We hypothesized that prolonged alcohol exposure directly to isolated demembranated cilia (axonemes) causes ciliary dysfunction. To test this hypothesis, we exposed isolated axonemes to alcohol (100 mM) for 1-24 h and assessed ciliary beat frequency (CBF) in response to cAMP at 1, 3, 4, 6, and 24 h post-exposure. We found that after 1 h of alcohol exposure, cilia axonemes do not increase CBF in response to cAMP. Importantly, by 6 h after the initial exposure to alcohol, cAMP-mediated CBF was restored to control levels. Additionally, we found that thioredoxin reverses ciliary dysfunction in axonemes exposed to alcohol. Finally, we identified, using a combination of a xanthine oxidase oxidant-generating system, direct application of hydrogen peroxide, and electron paramagnetic resonance, that hydrogen peroxide versus superoxide, is likely the key oxidant species driving alcohol-induced ciliary dysfunction in isolated axonemes. These data highlight the role of alcohol to stimulate local production of oxidants in the axoneme to cause ciliary dysfunction. Additionally, these data specifically add hydrogen peroxide as a potential therapeutic target in the treatment or prevention of alcohol-associated ciliary dysfunction and subsequent pneumonia.

Redox regulation of motile cilia in airway disease

Motile cilia on airway cells are necessary for clearance of mucus-trapped particles out of the lung. Ciliated airway epithelial cells are uniquely exposed to oxidants through trapping of particles, debris and pathogens in mucus and the direct exposure to inhaled oxidant gases. Dynein ATPases, the motors driving ciliary motility, are sensitive to the local redox environment within each cilium. Several redox-sensitive cilia-localized proteins modulate dynein activity and include Protein Kinase A, Protein Kinase C, and Protein Phosphatase 1. Moreover, cilia are rich in known redox regulatory proteins and thioredoxin domain-containing proteins that are critical in maintaining a balanced redox environment. Importantly, a nonsense mutation in TXNDC3, which contains a thioredoxin motif, has recently been identified as disease-causing in Primary Ciliary Dyskinesia, a hereditary motile cilia disease resulting in impaired mucociliary clearance. Here we review current understanding of the role(s) oxidant species play in modifying airway ciliary function. We focus on oxidants generated in the airways, cilia redox targets that modulate ciliary beating and imbalances in redox state that impact health and disease. Finally, we review disease models such as smoking, asthma, alcohol drinking, and infections as well as the direct application of oxidants that implicate redox balance as a modulator of cilia motility.

S-nitrosation of protein phosphatase 1 mediates alcohol-induced ciliary dysfunction

Alcohol use disorder (AUD) is a strong risk factor for development and mortality of pneumonia. Mucociliary clearance, a key innate defense against pneumonia, is perturbed by alcohol use. Specifically, ciliated airway cells lose the ability to increase ciliary beat frequency (CBF) to β-agonist stimulation after prolonged alcohol exposure. We previously found that alcohol activates protein phosphatase 1 (PP1) through a redox mechanism to cause ciliary dysfunction. Therefore, we hypothesized that PP1 activity is enhanced by alcohol exposure through an S-nitrosothiol-dependent mechanism resulting in desensitization of CBF stimulation. Bronchoalveolar S-nitrosothiol (SNO) content and tracheal PP1 activity was increased in wild-type (WT) mice drinking alcohol for 6-weeks compared to control mice. In contrast, alcohol drinking did not increase SNO content or PP1 activity in nitric oxide synthase 3-deficient mice. S-nitrosoglutathione induced PP1-dependent CBF desensitization in mouse tracheal rings, cultured cells and isolated cilia. In vitro expression of mutant PP1 (cysteine 155 to alanine) in primary human airway epithelial cells prevented CBF desensitization after prolonged alcohol exposure compared to cells expressing WT PP1. Thus, redox modulation in the airways by alcohol is an important ciliary regulatory mechanism. Pharmacologic strategies to reduce S-nitrosation may enhance mucociliary clearance and reduce pneumonia prevalence, mortality and morbidity with AUD.

Summary of the 2017 Alcohol and Immunology Research Interest Group (AIRIG) meeting

On June 24, 2017, the 22nd annual Alcohol and Immunology Research Interest Group (AIRIG) meeting was held as a satellite conference during the annual Research Society on Alcoholism (RSA) Scientific Meeting in Denver, Colorado. The 2017 meeting focused broadly on mechanisms that link alcohol to tissue injury and inflammation, and how this research can be translated to improve human health. Two plenary sessions composed the meeting, which first explored the association between alcohol and trauma/tissue injury, and finished with a discussion of alcohol and mucosal inflammation. The presentations encompassed diverse areas of alcohol research, from effects on the brain, to airway and pulmonary systems, to gut barrier disruption. The discussions also thoughtfully highlighted how current laboratory and clinical research can be used to prevent or treat alcohol-related morbidity and mortality.

Bioscavenger is effective as a delayed therapeutic intervention following percutaneous VX poisoning in the guinea-pig

The prolonged systemic exposure that follows skin contamination with low volatility nerve agents, such as VX, requires treatment to be given over a long time due to the relatively short half-lives of the therapeutic compounds used. Bioscavengers, such as butyrylcholinesterase (BChE), have been shown to provide effective post-exposure protection against percutaneous nerve agent when given immediately on signs of poisoning and to reduce reliance on additional treatments. In order to assess the benefits of administration of bioscavenger at later times, its effectiveness was assessed when administration was delayed for 2h after the appearance of signs of poisoning in guinea-pigs challenged with VX (4×LD₅₀). VX-challenged animals received atropine, HI-6 and avizafone on signs of poisoning and 2h later the same combination with or without bioscavenger. Five out of 6 animals which received BChE 2h after the appearance of signs of poisoning survived to the end of the study at 48h, compared with 6 out of 6 which received BChE immediately on signs. All the animals (n=6+6) that received only MedCM, without the addition of BChE, died within 10h of poisoning. The toxicokinetics of a sub-lethal challenge of percutaneous VX were determined in untreated animals. Blood VX concentration peaked at approximately 4h after percutaneous dosing with 0.4×LD₅₀; VX was still detectable at 36h and had declined to levels below the lower limit of quantification (10pg/mL) by 48h in 7 of 8 animals, with the remaining animal having a concentration of 12pg/mL. These studies confirm the persistent systemic exposure to nerve agent following percutaneous poisoning and demonstrate that bioscavenger can be an effective component of treatment even if its administration is delayed.

The efficacy of HI-6 DMS in a sustained infusion against percutaneous VX poisoning in the guinea-pig

Post-exposure nerve agent treatment usually includes administration of an oxime, which acts to restore function of the enzyme acetylcholinesterase (AChE). For immediate treatment of military personnel, this is usually administered with an autoinjector device, or devices containing the oxime such as pralidoxime, atropine and diazepam. In addition to the autoinjector, it is likely that personnel exposed to nerve agents, particularly by the percutaneous route, will require further treatment at medical facilities. As such, there is a need to understand the relationship between dose rate, plasma concentration, reactivation of AChE activity and efficacy, to provide supporting evidence for oxime infusions in nerve agent poisoning. Here, it has been demonstrated that intravenous infusion of HI-6, in combination with atropine, is efficacious against a percutaneous VX challenge in the conscious male Dunkin-Hartley guinea-pig. Inclusion of HI-6, in addition to atropine in the treatment, improved survival when compared to atropine alone. Additionally, erythrocyte AChE activity following poisoning was found to be dose dependent, with an increased dose rate of HI-6 (0.48mg/kg/min) resulting in increased AChE activity. As far as we are aware, this is the first study to correlate the pharmacokinetic profile of HI-6 with both its pharmacodynamic action of reactivating nerve agent inhibited AChE and with its efficacy against a persistent nerve agent exposure challenge in the same conscious animal.

Alcohol drives S-nitrosylation and redox activation of protein phosphatase 1, causing bovine airway cilia dysfunction

Individuals with alcohol (ethanol)-use disorders are at increased risk for lung infections, in part, due to defective mucociliary clearance driven by motile cilia in the airways. We recently reported that isolated, demembranated bovine cilia (axonemes) are capable of producing nitric oxide (^∙NO) when exposed to biologically relevant concentrations of alcohol. This increased presence of ^∙NO can lead to protein S-nitrosylation, a posttranslational modification signaling mechanism involving reversible adduction of nitrosonium cations or ^∙NO to thiolate or thiyl radicals, respectively, of proteins forming S-nitrosothiols (SNOs). We quantified and compared SNO content between isolated, demembranated axonemes extracted from bovine tracheae, with or without in situ alcohol exposure (100 mM × 24 h). We demonstrate that relevant concentrations of alcohol exposure shift the S-nitrosylation status of key cilia regulatory proteins, including 20-fold increases in S-nitrosylation of proteins that include protein phosphatase 1 (PP1). With the use of an ATP-reactivated axoneme motility system, we demonstrate that alcohol-driven S-nitrosylation of PP1 is associated with PP1 activation and dysfunction of axoneme motility. These new data demonstrate that alcohol can shift the S-nitrothiol balance at the level of the cilia organelle and highlight S-nitrosylation as a novel signaling mechanism to regulate PP1 and cilia motility.

Bodily attractiveness and egalitarianism are negatively related in males

Ancestrally, relatively attractive individuals and relatively formidable males may have had reduced incentives to be egalitarian (i.e., to act in accordance with norms promoting social equality). If selection calibrated one's egalitarianism to one's attractiveness/formidability, then such people may exhibit reduced egalitarianism ("observed egalitarianism") and be perceived by others as less egalitarian ("perceived egalitarianism") in modern environments. To investigate, we created 3D body models of 125 participants to use both as a source of anthropometric measurements and as stimuli to obtain ratings of bodily attractiveness and perceived egalitarianism. We also measured observed egalitarianism (via an economic "dictator" game) and indices of political egalitarianism (preference for socialism over capitalism) and "equity sensitivity." Results indicated higher egalitarianism levels in women than in men, and moderate-to-strong negative relationships between (a) attractiveness and observed egalitarianism among men, (b) attractiveness and perceived egalitarianism among both sexes, and (c) formidability and perceived egalitarianism among men. We did not find support for two previously-reported findings: that observed egalitarianism and formidability are negatively related in men, and that wealth and formidability interact to explain variance in male egalitarianism. However, this lack of support may have been due to differences in variable measurement between our study and previous studies.

Inhibition of protein phosphatase 1 reverses alcohol-induced ciliary dysfunction

Airway mucociliary clearance is a first-line defense of the lung against inhaled particles and debris. Among individuals with alcohol use disorders, there is an increase in lung diseases. We previously identified that prolonged alcohol exposure impairs mucociliary clearance, known as alcohol-induced ciliary dysfunction (AICD). Cilia-localized enzymes, known as the ciliary metabolon, are key to the pathogenesis of AICD. In AICD, cyclic nucleotide-dependent ciliary kinases, which modulate phosphorylation to regulate cilia beat, are desensitized. We hypothesized that alcohol activates cilia-associated protein phosphatase 1 (PP1) activity, driving phosphorylation changes of cilia motility regulatory proteins. To test this hypothesis we identified the effects of prolonged alcohol exposure on phosphatase activity, cilia beat, and kinase responsiveness and cilia-associated phosphorylation targets when stimulated by β-agonist or cAMP. Prolonged alcohol activated PP1 and blocked cAMP-dependent cilia beat and protein kinase A (PKA) responsiveness and phosphorylation of a 29-kDa substrate of PKA. Importantly, prolonged alcohol-induced phosphatase activation was inhibited by the PP1 specific inhibitor, inhibitor-2 (I-2), restoring cAMP-stimulated cilia beat and PKA responsiveness and phosphorylation of the 29-kDa substrate. The I-2 inhibitory effect persisted in tissue, cell, and isolated cilia-organelle models, highlighting the association of ciliary metabolon-localized enzymes to AICD. Prolonged alcohol exposure drives ciliary metabolon-localized PP1 activation. PP1 activation modifies phosphorylation of a 29-kDa protein related to PKA activity. These data reinforce our previous findings that alcohol is acting at the level of the ciliary metabolon to cause ciliary dysfunction and identifies PP1 as a therapeutic target to prevent or reverse AICD.

Bodily Attractiveness and Egalitarianism are Negatively Related in Males

Ancestrally, relatively attractive individuals and relatively formidable males may have had reduced incentives to be egalitarian (i.e., to act in accordance with norms promoting social equality). If selection calibrated one's egalitarianism to one's attractiveness/formidability, then such people may exhibit reduced egalitarianism (“observed egalitarianism”) and be perceived by others as less egalitarian (“perceived egalitarianism”) in modern environments. To investigate, we created 3D body models of 125 participants to use both as a source of anthropometric measurements and as stimuli to obtain ratings of bodily attractiveness and perceived egalitarianism. We also measured observed egalitarianism (via an economic “dictator” game) and indices of political egalitarianism (preference for socialism over capitalism) and “equity sensitivity.” Results indicated higher egalitarianism levels in women than in men, and moderate-to-strong negative relationships between (a) attractiveness and observed egalitarianism among men, (b) attractiveness and perceived egalitarianism among both sexes, and (c) formidability and perceived egalitarianism among men. We did not find support for two previously-reported findings: that observed egalitarianism and formidability are negatively related in men, and that wealth and formidability interact to explain variance in male egalitarianism. However, this lack of support may have been due to differences in variable measurement between our study and previous studies.

Female economic dependence and the morality of promiscuity

In environments in which female economic dependence on a male mate is higher, male parental investment is more essential. In such environments, therefore, both sexes should value paternity certainty more and thus object more to promiscuity (because promiscuity undermines paternity certainty). We tested this theory of anti-promiscuity morality in two studies (N = 656 and N = 4,626) using U.S. samples. In both, we examined whether opposition to promiscuity was higher among people who perceived greater female economic dependence in their social network. In Study 2, we also tested whether economic indicators of female economic dependence (e.g., female income, welfare availability) predicted anti-promiscuity morality at the state level. Results from both studies supported the proposed theory. At the individual level, perceived female economic dependence explained significant variance in anti-promiscuity morality, even after controlling for variance explained by age, sex, religiosity, political conservatism, and the anti-promiscuity views of geographical neighbors. At the state level, median female income was strongly negatively related to anti-promiscuity morality and this relationship was fully mediated by perceived female economic dependence. These results were consistent with the view that anti-promiscuity beliefs may function to promote paternity certainty in circumstances where male parental investment is particularly important.

The evolution of leader-follower reciprocity: the theory of service-for-prestige

We describe the service-for-prestige theory of leadership, which proposes that voluntary leader-follower relations evolved in humans via a process of reciprocal exchange that generated adaptive benefits for both leaders and followers. We propose that although leader-follower relations first emerged in the human lineage to solve problems related to information sharing and social coordination, they ultimately evolved into exchange relationships whereby followers could compensate leaders for services which would otherwise have been prohibitively costly for leaders to provide. In this exchange, leaders incur costs to provide followers with public goods, and in return, followers incur costs to provide leaders with prestige (and associated fitness benefits). Because whole groups of followers tend to gain from leader-provided public goods, and because prestige is costly for followers to produce, the provisioning of prestige to leaders requires solutions to the "free rider" problem of disrespectful followers (who benefit from leader services without sharing the costs of producing prestige). Thus service-for-prestige makes the unique prediction that disrespectful followers of beneficial leaders will be targeted by other followers for punitive sentiment and/or social exclusion. Leader-follower relations should be more reciprocal and mutually beneficial when leaders and followers have more equal social bargaining power. However, as leaders gain more relative power, and their high status becomes less dependent on their willingness to pay the costs of benefitting followers, service-for-prestige predicts that leader-follower relations will become based more on leaders' ability to dominate and exploit rather than benefit followers. We review evidential support for a set of predictions made by service-for-prestige, and discuss how service-for-prestige relates to social neuroscience research on leadership.

Why is low waist-to-chest ratio attractive in males? The mediating roles of perceived dominance, fitness, and protection ability

Past research suggests that a lower waist-to-chest ratio (WCR) in men (i.e., narrower waist and broader chest) is viewed as attractive by women. However, little work has directly examined why low WCRs are preferred. The current work merged insights from theory and past research to develop a model examining perceived dominance, fitness, and protection ability as mediators of to WCR-attractiveness relationship. These mediators and their link to both short-term (sexual) and long-term (relational) attractiveness were simultaneously tested by having 151 women rate one of 15 avatars, created from 3D body scans. Men with lower WCR were perceived as more physically dominant, physically fit, and better able to protect loved ones; these characteristics differentially mediated the effect of WCR on short-term, long-term, and general attractiveness ratings. Greater understanding of the judgments women form regarding WCR may yield insights into motivations by men to manipulate their body image.

Revisiting "The evolution of reciprocity in sizable groups": continuous reciprocity in the repeated n-person prisoner's dilemma

For many years in evolutionary science, the consensus view has been that while reciprocal altruism can evolve in dyadic interactions, it is unlikely to evolve in sizable groups. This view had been based on studies which have assumed cooperation to be discrete rather than continuous (i.e., individuals can either fully cooperate or else fully defect, but they cannot continuously vary their level of cooperation). In real world cooperation, however, cooperation is often continuous. In this paper, we re-examine the evolution of reciprocity in sizable groups by presenting a model of the n-person prisoner's dilemma that assumes continuous rather than discrete cooperation. This model shows that continuous reciprocity has a dramatically wider basin of attraction than discrete reciprocity, and that this basin's size increases with efficiency of cooperation (marginal per capita return). Further, we find that assortative interaction interacts synergistically with continuous reciprocity to a much greater extent than it does with discrete reciprocity. These results suggest that previous models may have underestimated reciprocity's adaptiveness in groups. However, we also find that the invasion of continuous reciprocators into a population of unconditional defectors becomes realistic only within a narrow parameter space in which the efficiency of cooperation is close to its maximum bound. Therefore our model suggests that continuous reciprocity can evolve in large groups more easily than discrete reciprocity only under unusual circumstances.

Do human parents face a quantity-quality tradeoff?: Evidence from a Shuar community

A number of evolutionary theories of human life history assume a quantity-quality tradeoff for offspring production: parents with fewer offspring can have higher biological fitness than those with more. Direct evidence for such a tradeoff, however, is mixed. We tested this assumption in a community of Ecuadorian Shuar hunter-horticulturalists, using child anthropometry as a proxy for fitness. We measured the impact of household consumer/producer (CP) ratio on height, weight, skinfold thicknesses, and arm and calf circumferences of 85 children and young adults. To control for possible "phenotypic" correlates that might mask the effect of CP ratio on anthropometry, we also measured household garden productivity, wealth, and social status. Regression models of the age-standardized variables indicated a significant negative impact of CP ratio on child growth and nutrition. The age-standardized height and weight of children in households with the largest CP ratio (10) were 1.38 and 1.44 standard deviations, respectively, below those of children in households with the smallest CP ratio (2). Surprisingly, garden productivity, wealth, and status had little to no effect on the fitness proxies. There was, however, an interesting and unexpected interaction between status and sex: for females, but not males, higher father status correlated significantly with higher values on the proxies.

Cognitive Adaptations for n-person Exchange: The Evolutionary Roots of Organizational Behavior

Organizations are composed of stable, predominantly cooperative interactions or n-person exchanges. Humans have been engaging in n-person exchanges for a great enough period of evolutionary time that we appear to have evolved a distinct constellation of species-typical mechanisms specialized to solve the adaptive problems posed by this form of social interaction. These mechanisms appear to have been evolutionarily elaborated out of the cognitive infrastructure that initially evolved for dyadic exchange. Key adaptive problems that these mechanisms are designed to solve include coordination among individuals, and defense against exploitation by free riders. Multi-individual cooperation could not have been maintained over evolutionary time if free riders reliably benefited more than contributors to collective enterprises, and so outcompeted them. As a result, humans evolved mechanisms that implement an aversion to exploitation by free riding, and a strategy of conditional cooperation, supplemented by punitive sentiment towards free riders. Because of the design of these mechanisms, how free riding is treated is a central determinant of the survival and health of cooperative organizations. The mapping of the evolved psychology of n-party exchange cooperation may contribute to the construction of a principled theoretical foundation for the understanding of human behavior in organizations.

Potential use of the alkaline comet assay as a predictor of bladder tumour response to radiation

Bladder tumours show a variable response to radiotherapy with only about 50% showing good local control; currently there is no test to predict outcome prior to treatment. We have used five bladder tumour cell lines (T24, UM-UC-3, TCC-SUP, RT112, HT1376) to investigate the potential of the alkaline comet assay (ACA) to predict radiosensitivity. Radiation-induced DNA damage and repair were compared to clonogenic survival. When the five cell lines were irradiated and initial DNA damage was plotted against cell survival, at all doses (0-6 Gy), a significant correlation was found (r2=0.9514). Following 4 Gy X-irradiation, all cell lines, except T24, showed a correlation between SF2 vs half-time for repair and SF2 vs residual damage at 5, 10, 20 and 30 min. The T24 cell line showed radioresistance at low doses (0-2 Gy) and radiosensitivity at higher doses (4-6 Gy) using both cell survival and ACA end points, explaining the lack of correlation observed for this cell line. These data indicate that initial DNA damage and residual damage can be used to predict for radiosensitivity. Our data suggest that predictive tests of radiosensitivity, appropriate to the clinical situation, may require the use of test doses in the clinical range.

Relationship between clonogenic radiosensitivity, radiation-induced apoptosis and DNA damage/repair in human colon cancer cells

The intrinsic radiation sensitivity of normal and tumour tissue is a major determinant of the outcome of radiotherapy. There is currently no established test that can be used routinely to measure the radiosensitivity of the cells in an individual patient's cancer in a manner that can inform treatment planning. The purpose of this study was to evaluate, in four human colorectal adenocarcinoma cell lines, two possible end points as surrogate markers of radiation response – apoptosis and induction of DNA single-strand breaks – and to compare the results with those of a conventional clonogenic assay. Cell lines (SW707 SW480, SW48 and HT29) known to differ in radiosensitivity were exposed to single doses of X-rays ranging from 0.5 to 5 Gy and cell survival was measured using the clonogenic assay. Apoptosis was determined on the basis of morphology under fluorescent microscopy and DNA damage/repair was measured, as tail moment, using an adaptation of the alkaline comet assay. The relationship between surviving fraction at 2 Gy (SF₂) and the percentage of apoptotic cells 24 h after the same dose was complex, but apoptosis accurately predicted the order of radiosensitivities as measured by SF₂. Initial damage measured after 2 Gy using the alkaline comet assay gave a close correlation with SF₂ (r²=0.95), whereas there was no correlation between initial DNA damage repair rate and SF₂.

Parental investment and child health in a Yanomamö village suffering short-term food stress

The 1998 El Niño significantly reduced garden productivity in the Upper Orinoco region in Venezuela. Consequently, parents were forced to allocate food carefully to their children. Nutrition data collected from village children combined with genealogical data allowed the determination of which children suffered most, and whether the patterns of food distribution accorded with predictions from parental investment theory. For boys, three social variables accounted for over 70% of the variance in subcutaneous fat after controlling for age: number of siblings, age of the mother's youngest child, and whether the mother was the senior or junior co-wife, or was married monogamously. These results accord well with parental investment theory. Parents experiencing food stress faced a trade-off between quantity and quality, and between investing in younger versus older offspring. In addition, boys with access to more paternal investment (i.e. no stepmother) were better nourished. These variables did not account for any of the variance in female nutrition. Girls' nutrition was associated with the size of their patrilineage and the number of non-relatives in the village, suggesting that lineage politics may have played a role. An apparent lack of relationship between orphan status and nutrition is also interesting, given that orphans suffered high rates of skin flea infections. The large number of orphans being cared for by only two grandparents suggests that grooming time may have been the resource in short supply.

Protein adsorption to polyethylene glycol modified liposomes from fibrinogen solution and from plasma

Unmodified and polyethylene glycol (PEG) modified neutral and negatively charged liposomes were prepared by freeze-thaw and extrusion followed by chromatographic purification. The effects of PEG molecular weight (PEG 550, 2000, 5000), PEG loading (0-15 mol%), and liposome surface charge on fibrinogen adsorption were quantified using radiolabeling techniques. All adsorption isotherms increased monotonically over the concentration range 0-3 mg/ml and adsorption levels were low. Negatively charged liposomes adsorbed significantly more fibrinogen than neutral liposomes. PEG modification had no effect on fibrinogen adsorption to neutral liposomes. An inverse relationship was found between PEG loading of negatively charged liposomes and fibrinogen adsorption. PEGs of all three molecular weights at a loading of 5 mol% reduced fibrinogen adsorption to negatively charged liposomes. Protein adsorption from diluted plasma (10% normal strength) to four different liposome types (neutral, PEG-neutral, negatively charged, and PEG-negatively charged) was investigated using gel electrophoresis and immunoblotting. The profiles of adsorbed proteins were similar on all four liposome types, but distinctly different from the profile of plasma itself, indicating a partitioning effect of the lipid surfaces. alpha2-macroglobulin and fibronectin were significantly enriched on the liposomes whereas albumin, transferrin, and fibrinogen were depleted compared to plasma. Apolipoprotein AI was a major component of the adsorbed protein layers. The blot of complement protein C3 adsorbed on the liposomes suggested that the complement system was activated.

Description and use of the neuroscience nursing self-efficacy scale

An instrument for assessing nurses' perceived self-efficacy in implementing a variety of neuroscience nursing tasks was developed. Self-efficacy theory served as the guiding framework. From 1988 to 1998, the instrument was used to assess changes in the perceived self-efficacy of 54 nurses who attended a neuroscience nurse-internship program. Self-efficacy was assessed during clinical orientation, prior to the beginning of the program, and at the end of the program. The results showed that the nurses' confidence in performing a variety of neuroscience nursing skills increased during the 6- to 10-month program. The instrument was also useful in helping program directors identify areas in which nurses could benefit most from the program and refine the program to meet the educational needs of the nurses.

Evaluation of the Neuroscience Nurse Internship Program: the first decade

This article describes the evaluation of the Neuroscience Nurse Internship Program (NNIP). The NNIP was initiated in 1988 by the National Institutes of Health Clinical Center to meet the demand for highly skilled nurses to care for persons with nervous system disorders. To determine whether the program was meeting its goals, an evaluation component was incorporated into the program. The evaluation process was based on the RSA Model of Continuing Education for nursing. The RSA model consists of four basic components, three of which were included in the assessment of the NNIP--process, content, and outcome. The evaluation revealed that the nurse-interns were satisfied with the lectures and clinical content of the program. Moreover, the nurse-interns improved their knowledge of neuroscience nursing and their confidence in performing neuroscience nursing skills. Information from the evaluation was used to modify the structure of the program and to refine lecture content and clinical requirements.

The Neuroscience Nurse Internship Program: the description

This article describes the Neuroscience Nurse Internship Program (NNIP) and its implementation at the National Institutes of Health (NIH) Clinical Center in Bethesda, MD. The program, developed in 1988, is designed to prepare nurses to deliver care to persons with nervous system disorders. The program comprises 6 months of lecture and clinical instruction in the country's most well-known biomedical research center. In order to complete the program, nurse-interns must receive a passing grade of 90% or higher on all written tests and achieve satisfactory completion of all clinical assignments. NNIP is cosponsored by the NIH Clinical Center Nursing Department and the National Institute of Neurological Disorders and Stroke (NINDS). Nurses interested in NNIP may apply by submitting an application and a letter of interest to the Clinical Center Human Resources Department. Evaluation of the program is conducted on a regular basis and consists of both process and outcome assessments.

Discovery of RWJ-54428 (MC-02,479), a new cephalosporin active against resistant gram-positive bacteria

The discovery of RWJ-54428 (MC-02,479), a new cephalosporin displaying promising activity against sensitive and resistant Gram-positive bacteria, is described. Progressive structural modification from the previously reported 3-phenylthiocephem MC-02,331 afforded an overall increase in potency against MRSA while retaining other key properties such as acceptable solubility and serum binding. Evaluation of the in vitro potency and in vivo efficacy of a series of closely related compounds resulted in selection of RWJ-54428 (MC-02,479) for further studies.

Induction and rejoining of DNA double-strand breaks in bladder tumor cells

The induction and rejoining of radiation-induced double-strand breaks (DSBs) in cells of six bladder tumor cell lines (T24, UM-UC-3, TCC-SUP, RT112, J82, HT1376) were measured using the neutral comet assay. Radiation dose-response curves (0-60 Gy) showed damage (measured as mean tail moment) for five of the cell lines in the same rank order as cell survival (measured over 0-10 Gy), with the least damage in the most radioresistant cell line. Damage induction correlated well with clonogenic survival at high doses (SF10) for all six cell lines. At the clinically relevant dose of 2 Gy, correlation was good for four cell lines but poor for two (TCC-SUP and T24). The rejoining process had a fast and slow component for all cell lines. The rate of these two components of DNA repair did not correlate with cell survival. However, the time taken to reduce the amount of DNA damage to preirradiated control levels correlated positively with cell survival at 10 Gy but not 2 Gy; radioresistant cells rejoined the induced DSBs to preirradiation control levels more quickly than the radiosensitive cells. Although the results show good correlation between SF10 and DSBs for all six cell lines, the lack of correlation with SF2 for TCC-SUP and T24 cells would suggest that a predictive test should be carried out at the clinically relevant dose. At present the neutral comet assay cannot achieve this.

Increased repair and cell survival in cells treated with DIR1 antisense oligonucleotides: implications for induced radioresistance

PURPOSE

To determine whether repression of a recently isolated, X-ray-responsive gene, DIR1, using antisense oligonucleotides could affect clonogenic cell survival and repair of DNA strand breaks and have a possible role in the mechanism underlying the phenomenon of 'induced radioresistance' (IRR).

MATERIALS AND METHODS

Three cell lines, V79, RT112 and UM-UC-3, which are known to exhibit low-dose hypersensitivity (HRS) and induced radioresistance (IRR), and the radiosensitive cell line ATBIVA, were transfected with antisense oligonucleotides directed towards the DIR1 gene. Scrambled oligonucleotides were used as controls. DNA single-strand break (ssb) repair, using the alkaline comet assay, and cell survival using a standard clonogenic assay was measured after exposure to X-rays.

RESULTS

Following treatment with 4Gy X-rays, the V79, RT112 and UM-UC-3 cell lines all exhibited significantly increased rates of ssb repair after transfection with DIR1 antisense oligonucleotides compared with cells transfected with scrambled oligonucleotides. They also demonstrated significantly enhanced survival after exposure to 2 Gy X-rays; the radiosensitive ATBIVA cells did not show these effects.

CONCLUSIONS

Repression of the DIR1 gene product leads to an increase in the rate of repair and cell survival in three radioresistant cells lines but not in the radiosensitive ATBIVA cell line. Because DIR1 is repressed by X-rays in the dose range where IRR is observed, it may represent a candidate gene involved in the IRR phenomenon.

A novel human stress response-related gene with a potential role in induced radioresistance

We have isolated a novel gene, DIR1, from L132 cells that is transiently repressed after exposure to low radiation doses and has a potential role in induced radioresistance. Molecular and cellular characterization of this gene reveals that it is unique but has similarities to a family of heat-shock-related proteins known as immunophilins. These have been implicated in various cellular functions including general stress responses and control of the cell cycle. Antisense strategies have demonstrated that the DIR1 gene also appears to have some involvement in the control of the cell cycle. Furthermore, there appears be a potential role for this gene product in the phenomenon of induced radioresistance through a mechanism that increases the rate of DNA repair in cells exposed to X rays and subsequently increases the cells' resistance to radiation. This is the first description of an immunophilin-like gene that has a possible role in adaptive/inducible responses to X rays in mammalian cells.

Discovery of MC-02,331, a new cephalosporin exhibiting potent activity against methicillin-resistant Staphylococcus aureus

A systematic approach toward building activity against methicillin-resistant staphylococci into the cephalosporin class of beta-lactam antibiotics is described. Initial work focused on finding the optimal linkage between the cephem nucleus and a biphenyl pharmacophore, which established that a thio linkage afforded potent activity in vitro. Efforts to optimize this activity by altering substitution on the pharmacophore afforded iodophenylthio analog MC-02,002, which although highly potent against MRSA, was also highly bound to serum proteins. Further work to decrease serum protein binding showed that replacement of the iodo substituent by the positively-charged isothiouronium group afforded potent activity and reduced serum binding, but insufficient aqueous solubility. Solubility was enhanced by incorporation of a second positively-charged group into the 7-acyl substituent. Such derivatives (MC-02,171 and MC-02,306) lacked sufficient stability to staphylococcal beta-lactamase enzymes. The second positive charge was incorporated into the cephem 3-substituent in order to utilize the beta-lactamase-stable aminothiazolyl(oximino)acetyl class of 7-substituents. These efforts culminated with the discovery of bis(isothiouroniummethyl)phenylthio analog MC-02,331, whose profile is acceptable with respect to potency against MRSA, serum binding, aqueous solubility, and beta-lactamase stability.

Effects of sildenafil on the relaxation of human corpus cavernosum tissue in vitro and on the activities of cyclic nucleotide phosphodiesterase isozymes

PURPOSE

Sildenafil, an inhibitor of cGMP-specific phosphodiesterase 5 (PDE5), is currently undergoing evaluation as an oral therapy for penile erectile dysfunction. The aims of this study were to investigate the mechanism of action of sildenafil on the neurogenic relaxation of human corpus cavernosum (HCC) in vitro and to determine the activity of sildenafil against a full range of PDE isozymes.

MATERIALS AND METHODS

Strips of HCC tissue were precontracted with phenylephrine. Relaxation responses resulting from electrical field stimulation (EFS) were then determined in the presence and absence of sildenafil. The effects of sildenafil on PDE1 to 5 prepared from human tissues and PDE6 from bovine retina were determined by measuring the conversion of [3H]-cGMP or [3H]-cAMP to their respective [3H]-5'-mononucleotides.

RESULTS

Sildenafil (0.001 to 1 microM) enhanced the EFS-induced, nitric oxide (NO) dependent, relaxation of HCC in a concentration-dependent manner to a maximum of 3 times the pretreatment level at 1 microM sildenafil. Compared with zaprinast, an early PDE5 inhibitor, sildenafil was approximately 240-fold more potent, inhibiting PDE5 from HCC with a geometric mean IC50 of 3.5 nM. For sildenafil, IC50 values for inhibition of PDE1 to 4 were 80 to more than 8500 times greater than that for PDE5 and the IC50 for PDE6 (33 nM) was approximately 9-fold greater.

CONCLUSIONS

The data support the proposal that enhancement of penile erection by sildenafil in patients with erectile dysfunction involves potentiation of the NO-stimulated cGMP signal mediating relaxation of cavernosal smooth muscle during sexual stimulation. Sildenafil is a potent inhibitor of PDE5 from HCC, with high selectivity for PDE5 relative to other PDE isozymes.

Effects of sildenafil on the relaxation of human corpus cavernosum tissue in vitro and on the activities of cyclic nucleotide phosphodiesterase isozymes

PURPOSE

Sildenafil, an inhibitor of cGMP-specific phosphodiesterase 5 (PDE5), is currently undergoing evaluation as an oral therapy for penile erectile dysfunction. The aims of this study were to investigate the mechanism of action of sildenafil on the neurogenic relaxation of human corpus cavernosum (HCC) in vitro and to determine the activity of sildenafil against a full range of PDE isozymes.

MATERIALS AND METHODS

Strips of HCC tissue were precontracted with phenylephrine. Relaxation responses resulting from electrical field stimulation (EFS) were then determined in the presence and absence of sildenafil. The effects of sildenafil on PDE1 to 5 prepared from human tissues and PDE6 from bovine retina were determined by measuring the conversion of [3H]-cGMP or [3H]-cAMP to their respective [3H]-5'-mononucleotides.

RESULTS

Sildenafil (0.001 to 1 microM) enhanced the EFS-induced, nitric oxide (NO) dependent, relaxation of HCC in a concentration-dependent manner to a maximum of 3 times the pretreatment level at 1 microM sildenafil. Compared with zaprinast, an early PDE5 inhibitor, sildenafil was approximately 240-fold more potent, inhibiting PDE5 from HCC with a geometric mean IC50 of 3.5 nM. For sildenafil, IC50 values for inhibition of PDE1 to 4 were 80 to more than 8500 times greater than that for PDE5 and the IC50 for PDE6 (33 nM) was approximately 9-fold greater.

CONCLUSIONS

The data support the proposal that enhancement of penile erection by sildenafil in patients with erectile dysfunction involves potentiation of the NO-stimulated cGMP signal mediating relaxation of cavernosal smooth muscle during sexual stimulation. Sildenafil is a potent inhibitor of PDE5 from HCC, with high selectivity for PDE5 relative to other PDE isozymes.

Second 46,XX male with MLS syndrome

We report on a second 46,XX male with microphthalmia with linear skin defects (MLS) syndrome. In addition to microphthalmia and linear skin streaks, he had a secundum ASD, hypospadias with chordee, anal fistula, and agenesis of corpus callosum with colpocephaly. Biopsy of a linear streak showed smooth muscle hamartomata rather than the presumed dermal aplasia. Detailed ophthalmologic examination did not show retinal lacunae typical of Aicardi syndrome. DNA studies with distal Xp specific probes indicated a deletion in one X chromosome and fluorescence in situ hybridization (FISH) studies with X- and Y-specific probes demonstrated the presence of a derivative X chromosome from an X;Y translocation.

Evaluation of glucose monitoring devices in the hyperbaric chamber

Diabetic patients may experience fluctuations in whole blood glucose (WBG) levels while receiving hyperbaric oxygen therapy (HBO) resulting in seizure-like activity. Therefore, hyperbaric medical attendants must accurately monitor the WBG levels of these patients during HBO. In addressing this concern, this study evaluated the accuracy and reliability of commercially available glucometers (Glucometer M+, Companion 2, HemoCue, One Touch II, and ExacTech Pen) in the hyperbaric environment. WBG samples were prepared, ranging from 25 to 250 mg/dl, for testing glucometers at ground level and at 2.36 atmospheres absolute (ATA). It was noted that at 2.36 ATA, glucose values increased using the Glucometer M+, but decreased with the Companion 2 and HemoCue. The One Touch II values decreased in the hyperglycemic ranges (> 150 mg/dl), whereas the ExacTech Pen monitor readings increased in the hypoglycemic ranges (< 100 mg/dl). The accuracy of WBG monitors is significantly affected by changes in atmospheric pressure.

Structure of an unusually non-polar hydroxy ether

(1R*,3R*,7S*,9S*)-1,4,4-Trimethyl-9-(tert-butyldimethylsilyloxy)-e xo-11-oxatricyclo[5.3.1.0(2,6)]-undecan-3-ol, C19H36O3Si, Mr = 340.90, orthorhombic, Pbca, a = 10.411 (3), b = 13.275 (3), c = 29.085 (10) A, V = 4019 (2) A3, Z = 8, Dx (130 K) = 1.13 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 1.24 cm-1, F(000) = 1504, T = 130 K, R = 0.077 for 1005 observed reflections with I greater than 3 sigma(I). The compound, whose connectivity was not readily apparent from spectroscopic and chemical information alone, possesses a tricyclic framework containing an O-bridged bicyclo[3.2.1]octane fused in a cis-exo manner to a cyclopentanol ring. Most noteworthy is the considerably lower polarity of this compound relative to its opposite cyclopentanol stereoisomer. The close proximity [2.78 (1) A] of the bridging O atom in the [3.2.1] system to the hydroxyl O atom on the five-membered ring is suggestive of an intramolecular hydrogen bond, although the H atom could not be located.

Rational selective exploitation and distress: Employee reactions to performance-based and mobility-based reward allocations

Prior research has demonstrated that allocators frequently distribute greater rewards to persons with high professional and geographic mobility than to persons with constrained mobility, especially among the very competent. This phenomenon has been termed rational selective exploitation. Do the recipients of such allocations actually experience this distribution rule as unjust and distressing, or is it a misnomer to refer to this phenomenon as exploitation? Two studies were conducted to explore this question. Study 1 was a laboratory experiment in which we manipulated relative performance level, relative mobility level, and allocation standard: performance based versus mobility based. Study 2 was a cross-sectional survey of actual employees in which subjects reported the degree to which performance and mobility were the basis for pay decisions at their places of employment, as well as the degree to which they perceived each standard to be fair. Both studies demonstrated that people regard mobility-based allocations as less fair and more distressing than performance-based allocations. Furthermore, the degree of distress resulting from mobility-based allocations is greater among persons who are disadvantaged by that standard: among people with constrained mobility, especially those who perform at high levels. These findings provide good support for the assertion that so-called rational selective exploitation is indeed distressing to employees. Reactions to this form of distress are also explored, and the implications of these findings for the allocation process are discussed.