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Background: Little is known about risk factors for anxiety in young children. The current study investigated the value of a set of theoretically derived risk factors to predict symptoms of anxiety in a sample of preschool-aged children. Methods: Mothers (n = 632) and fathers (n = 249) completed questionnaires twice, 12 months apart. Measures were selected to assess several risk factors derived from current theory, including parental negative affectivity, child inhibition, parent overprotection, and impact of life events. Results: Even at this young age anxiety across 12 months was moderately to highly stable (r's = 0.75 and 0.74 based on maternal and paternal report respectively). Over and above this stability, according to maternal report, anxiety at 12 months was significantly predicted by prior maternal overprotection, impact of negative life events, child's inhibition, and maternal negative affectivity. According to paternal report, anxiety at 12 months was significantly predicted by prior paternal overprotection and impact of negative life events. The models did not differ significantly for girls and boys. Conclusions: The results support theories of the development of anxiety, especially the role of parental and external environmental factors, and point to possible targets for prevention of heightened anxiety in young children.

The purpose of this study was to test the validity and factorial structure of a modified version of the Preschool Anxiety Scale (Spence, Rapee, McDonald, & Ingram, 2001). The measure was completed by 764 mothers and 418 fathers of children aged 3 to 5 years. After removing, two items tapping obsessive compulsive symptoms, confirmatory factor analysis showed that a four-factor model (social anxiety, generalized anxiety, separation anxiety, specific fears) all loading on a higher order "anxiety" factor, provided an optimal fit for the data. The total scale and 4 subscales showed strong internal consistency (alphas = 0.72-0.92), 12-month stability y (rs = 0.60-0.75) and maternal/paternal agreement (rs = 0.60-0.75). Scores on the scale also showed expected correlations with a measure of emotional distress, diagnosed anxiety disorders, and behavioral indicators of anxiety. (Contains 1 footnote and 6 tables.)

The efficacy of early intervention for preschool-aged children at risk of anxiety disorders is investigated. Brief early intervention delivered through parents can reduce anxiety and associated risk and may alter the developmental trajectory of anxiety in some young children.

Aim: Pacific hagfish are exceptionally tolerant to high environmental ammonia (HEA). Here, we elucidated a cellular mechanism that enables hagfish to actively excrete ammonia against steep ammonia gradients expected to be found inside a decomposing whale carcass. Methods: Hagfish were exposed to varying concentrations of HEA in the presence or absence of environmental Na+, while plasma ammonia levels were tracked. 14C‐methylammonium was used as a proxy for NH4+ to measure efflux in whole animals and in isolated gill pouches; the latter allowed us to assess the effects of amiloride specifically on Na+/H+ exchangers (NHEs) in gill cells. Western blotting and immunohistochemistry were utilized to evaluate the abundance and sub‐cellular localization of Rhesus glycoprotein (Rh) channels in the response to HEA. Results: Hagfish actively excreted NH4+ against steep inwardly directed ENH4+ (ΔENH4+ ~ 35 mV) and pNH3 (ΔpNH3 ~ 2000 μtorr) gradients. Active NH4+ excretion and plasma ammonia hypo‐regulation were contingent on the presence of environmental Na+, indicating a Na+/NH4+ exchange mechanism. Active NH4+ excretion across isolated gill pouches was amiloride‐sensitive. Exposure to HEA resulted in decreased abundance of Rh channels in the apical membrane of gill ionocytes. Conclusions: During HEA exposure, hagfish can actively excrete ammonia against a steep concentration gradient using apical NHEs energized by Na+‐K+‐ATPase in gill ionocytes. Additionally, apical Rh channels are removed from the apical membrane, presumably to reduce ammonia loading from the environment. We suggest that this mechanism allows hagfish to maintain tolerable ammonia levels while feeding inside decomposing carrion, allowing them to exploit nutrient‐rich food‐falls. [ABSTRACT FROM AUTHOR]

School-based relationship education programs offer an opportunity to identify youth who are experiencing teen dating violence (TDV), support their safety, and connect them with individualized services or referrals. However, no research has tested the feasibility or accuracy of approaches to create opportunities for TDV disclosure in the context of school-based programs. The current study presents the results of a field test comparing three tools used to provide opportunities for TDV disclosure (two questionnaire-style tools and one universal education discussion guide). High school students from two federally funded healthy marriage and relationship education (HMRE) program sites (N = 648) were offered the three tools in random order over the course of the HMRE program, which lasted between 3 weeks and 3 months and took place during the school day. Onsite qualitative interviews with HMRE program staff and their local domestic violence program partners assessed how service providers saw the tools and the process of implementing them. Latent class models examined the accuracy of the tools in identifying TDV. Sensitivities of the tools were low and specificities were high; the questionnaire-style tools tended to have higher sensitivities and fewer classification errors than the universal education tool. Several three-item combinations from across the tools performed better than any intact tool, suggesting that shorter assessments may be effective, provided they include items on sexual coercion and physical violence. Qualitative findings suggested that implementation of TDV assessment and universal education in school settings is a viable strategy, provided programs are able to gain support from school staff, adapt to tight time constraints, and plan procedures for protecting student privacy and confidentiality. [ABSTRACT FROM AUTHOR]

The dogfish (Squalus acanthias) can make rapid adjustments to gill acid-base transfers to compensate for internal acidosis/alkalosis. Branchial [Na.sup.+]/[H.sup.+] exchange (NHE) has been postulated as one mechanism driving the excretion of [H.sup.+] following acidosis. We have cloned gill cDNA that includes an open reading frame coding for a 770-residue protein most homologous (~71%) to mammalian NHE2. RT-PCR revealed NHE2 transcripts predominantly in gill, stomach, rectal gland, intestine, and kidney. In situ hybridization with an antisense probe against NHE2 in gill sections revealed a strong mRNA signal from a subset of interlamellar and lamellae cells. We developed dogfish-specific polyclonal antibodies against NHE2 that detected a ~70-kDa protein in Western blots and immunologically recognized branchial cells having two patterns of protein expression. Cytoplasmic and apical NHE2 immunoreactivity were observed in cells coexpressing basolateral [Na.sup.+]-[K.sup.+]-ATPase. Other large ovoid cells more generally staining for NHE2 also were strongly positive for basolateral [H.sup.+]-ATPase. Gill mRNA levels for NHE2 and [H.sup.+]-ATPase did not change following systemic acidosis (as measured by quantitative PCR 2 h after a 1- or 2-meq/kg acid infusion). These data indicate that posttranslational adjustments of NHE2 and other transport systems (e.g., NHE3) following acidosis may be of importance in the short-term pH adjustment and net branchial [H.sup.+] efflux observed in vivo. NHE2 may play multiple roles in the gills, involved with [H.sup.+] efflux from acid-secreting cells, basolateral [H.sup.+] reabsorption for [pH.sub.i] regulation, and in parallel with [H.sup.+]-ATPase for the generation of [HCO.sup.-.sub.3] in base-secreting cells. acid-base regulation; branchial; elasmobranch; sodium/hydrogen antiporter

The acute effect of metabolic acidosis on S[O.suo.2-.sub.4] secretion by the marine teleost renal proximal tubule was examined. Metabolic acidosis was mimicked in primary cultures of winter flounder renal proximal tubule epithelium (fPTCs) mounted in Ussing chambers by reducing interstitial pH to 7.1 (normally 7.7). fPTCs with metabolic acidosis secreted S[O.suo.2-.sub.4] at a net rate that was 40% higher than in paired isohydric controls (pH 7.7 on interstitium). The stimulation was completely blocked by the carbonic anhydrase inhibitor methazolamide (100 [micro]M). Although [Na.sup.a]/[H.sup.+] exchange (NHE) isoforms 1, 2, and 3 were identified in fPTCs by immunoblotting, administering EIPA (20 [micro]M) to the interstitial and luminal bath solutions had no effect on net S[O.suo.2-.sub.4] secretion by fPTCs with a normal interstitial pH of 7.7. However, EIPA (20 [micro]M) blocked most of the stimulation caused by acidosis when applied to the lumen but not interstitium, demonstrating that induction of brush-border NHE activity is important. In the intact flounder, serum pH dropped 0.4 pH units (pH 7.7 to 7.3, at 2-3 h) when environmental pH was lowered from 7.8 to ~4.3. Whereas serum [S[O.suo.2-.sub.4]] was not altered by acidosis, renal tubular S[O.suo.2-.sub.4] secretion rate was elevated 200%. Thus metabolic acidosis strongly stimulates renal sulfate excretion most likely by a direct effect on active renal proximal tubule S[O.suo.2-.sub.4] secretion. This stimulation appears to be dependent on inducible brush-border NHE activity. proximal tubule; epithelial transport; metabolic alkalosis; transport metabolon; marine teleost

The dogfish (Squalus acanthias) can make rapid adjustments to gill acid-base transfers to compensate for internal acidosis/alkalosis. Branchial Na+/H+ exchange (NHE) has been postulated as one mechanism driving the excretion of H+ following acidosis. We have cloned gill cDNA that includes an open reading frame coding for a 770-residue protein most homologous (~71%) to mammalian NHE2. RT-PCR revealed NHE2 transcripts predominantly in gill, stomach, rectal gland, intestine, and kidney. In situ hybridization with an antisense probe against NHE2 in gill sections revealed a strong mRNA signal from a subset of interlamellar and lamellae cells. We developed dogfish-specific polyclonal antibodies against NHE2 that detected a +70-kDa protein in Western blots and immunologically recognized branchial cells having two patterns of protein expression. Cytoplasmic and apical NHE2 immunoreactivity were observed in cells coexpressing basolateral Na+-K+-ATPase. Other large ovoid cells more generally staining for NHE2 also were strongly positive for basolateral H+-ATPase. Gill mRNA levels for NHE2 and H+-ATPase did not change following systemic acidosis (as measured by quantitative PCR 2 h after a1- or 2-meq/kg acid infusion). These data indicate that posttranslational adjustments of NHE2 and other transport systems (e.g., NHE3) following acidosis may be of importance in the short-term pH adjustment and net branchial H+ effiux observed in vivo. NHE2 may play multiple roles in the gills, involved with H+ efflux from acid-secreting cells, basolateral H+ reabsorption for pH+ regulation, and in parallel with H+-ATPase for the generation of HCO3- in base-secreting cells. [ABSTRACT FROM AUTHOR]

Abstract: We recently cloned an NHE3 orthologue from the gills of the euryhaline Atlantic stingray (Dasyatis sabina), and generated a stingray NHE3 antibody to unequivocally localize the exchanger to the apical side of epithelial cells that are rich with Na+/K+-ATPase (A MRC). We also demonstrated an increase in NHE3 expression when stingrays are in fresh water, suggesting that NHE3 is responsible for active Na+ absorption. However, the vast majority of elasmobranchs are only found in marine environments. In the current study, immunohistochemistry with the stingray NHE3 antibody was used to localize the exchanger in the gills of the stenohaline marine spiny dogfish shark (Squalus acanthias). NHE3 immunoreactivity was confined to the apical side of cells with basolateral Na+/K+-ATPase and was excluded from cells with high levels of vacuolar H+-ATPase. Western blots detected a single protein of 88 kDa in dogfish gills, the same size as NHE3 in stingrays and mammals. These immunological data demonstrate that the putative cell type responsible for active Na+ absorption in euryhaline elasmobranchs is also present in stenohaline marine elasmobranchs, and suggest that the inability of most elasmobranchs to survive in fresh water is not due to a lack of the gill ion transporters for Na+ absorption. [Copyright &y& Elsevier]

Long-term pH compensation in a marine teleost requires the transepithelial excretion of H+ across the gill epithelium. H+ efflux in the longhorn sculpin (Myoxocephalus octodecemspinosus) is dependent on external sodium ion concentration and is inhibited by known inhibitors of Na+/H+ exchangers. Our model for proton transport suggests acid-excreting cells in the gill with an apical Na+/H+ antiporter and basolateral Na+/K+-ATPase. This model is similar to mammalian kidney and elasmobranch gill epithelium in which a basolateral electrogenic-vacuolar proton pump (V-H+-ATPase) localizes to base-excreting cells. The objective of this study was to detect the presence and location of membrane transporters in marine fish gills using immunohistochemical staining. Our data indicate the presence of an apical and subapical Na+/H+-exchanger 2 (NHE2) in the sculpin gill. NHE2 is present in large, ovoid chloride cells and often colocalizes in the same cells as Na+/K+-ATPase. We also detected V-H+-ATPase immunoreactivity, predominantly in cells at the base of the lamellae, with staining patterns indicative of a basolateral location. The 85 kDa protein detected on immunoblots with anti-NHE2 antibodies was found in both control and acid-infused animals and did not change following a large acute acidosis over 8 h. [ABSTRACT FROM AUTHOR]

The acute effect of metabolic acidosis on SO42- secretion by the marine teleost renal proximal tubule was examined. Metabolic acidosis was mimicked in primary cultures of winter flounder renal proximal tubule epithelium (fPTCs) mounted in Ussing chambers by reducing interstitial pH to 7.1 (normally 7.7). fPTCs with metabolic acidosis secreted SO42- at a net rate that was 40% higher than in paired isohydric controls (pH 7.7 on interstitium). The stimulation was completely blocked by the carbonic anhydrase inhibitor methazolamide (100 µM). Although Na+/H+ exchange (NHE) isoforms 1, 2, and 3 were identified in fPTCs by immunoblotting, administering EIPA (20 µM) to the interstitial and luminal bath solutions had no effect on net SO42- secretion by fPTCs with a normal interstitial pH of 7.7. However, EIPA (20 µM) blocked most of the stimulation caused by acidosis when applied to the lumen but not interstitium, demonstrating that induction of brush-border NHE activity is important. In the intact flounder, serum pH dropped 0.4 pH units (pH 7.7 to 7.3, at 2-3 h) when environmental pH was lowered from 7.8 to ∼4.3. Whereas serum [SO42-] was not altered by acidosis, renal tubular SO42- secretion rate was elevated 200%. Thus metabolic acidosis strongly stimulates renal sulfate excretion most likely by a direct effect on active renal proximal tubule SO42- secretion. This stimulation appears to be dependent on inducible brush-border NHE activity. [ABSTRACT FROM AUTHOR]

Aim: Pacific hagfish are exceptionally tolerant to high environmental ammonia (HEA). Here, we elucidated a cellular mechanism that enables hagfish to actively excrete ammonia against steep ammonia gradients expected to be found inside a decomposing whale carcass., Methods: Hagfish were exposed to varying concentrations of HEA in the presence or absence of environmental Na + , while plasma ammonia levels were tracked. 14 C-methylammonium was used as a proxy for NH 4 + to measure efflux in whole animals and in isolated gill pouches; the latter allowed us to assess the effects of amiloride specifically on Na + /H + exchangers (NHEs) in gill cells. Western blotting and immunohistochemistry were utilized to evaluate the abundance and sub-cellular localization of Rhesus glycoprotein (Rh) channels in the response to HEA., Results: Hagfish actively excreted NH 4 + against steep inwardly directed E NH4 + (ΔE NH4 +  ~ 35 mV) and pNH 3 (ΔpNH 3  ~ 2000 μtorr) gradients. Active NH 4 + excretion and plasma ammonia hypo-regulation were contingent on the presence of environmental Na + , indicating a Na + /NH 4 + exchange mechanism. Active NH 4 + excretion across isolated gill pouches was amiloride-sensitive. Exposure to HEA resulted in decreased abundance of Rh channels in the apical membrane of gill ionocytes., Conclusions: During HEA exposure, hagfish can actively excrete ammonia against a steep concentration gradient using apical NHEs energized by Na + -K + -ATPase in gill ionocytes. Additionally, apical Rh channels are removed from the apical membrane, presumably to reduce ammonia loading from the environment. We suggest that this mechanism allows hagfish to maintain tolerable ammonia levels while feeding inside decomposing carrion, allowing them to exploit nutrient-rich food-falls., (© 2022 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.)

Hagfish consume carrion, potentially exposing them to hypoxia, hypercapnia, and high environmental ammonia (HEA). We investigated branchial and cutaneous ammonia handling strategies by which Pacific hagfish ( Eptatretus stoutii ) tolerate and recover from high ammonia loading. Hagfish were exposed to HEA (20 mmol/l) for 48 h to elevate plasma total ammonia (T Amm ) levels before placement into divided chambers for a 4-h recovery period in ammonia-free seawater where ammonia excretion ( J Amm ) was measured independently in the anterior and posterior compartments. Localized HEA exposures were also conducted by subjecting hagfish to HEA in either the anterior or posterior compartments. During recovery, HEA-exposed animals increased J Amm in both compartments, with the posterior compartment comprising ~20% of the total J Amm was concentration dependent (0.05-5 mmol/l) across excised skin patches at up to eightfold greater rates than in skin sections that were excised from HEA-exposed hagfish. Skin excised from more posterior regions displayed greater Amm increased substantially when whole hagfish and the posterior regions were exposed to HEA. Alternatively, plasma T Amm did not elevate after anterior localized HEA exposure. J Amm was concentration dependent (0.05-5 mmol/l) across excised skin patches at up to eightfold greater rates than in skin sections that were excised from HEA-exposed hagfish. Skin excised from more posterior regions displayed greater J Amm than those from more anterior regions. Immunohistochemistry with hagfish-specific anti-rhesus glycoprotein type c (α-hRhcg; ammonia transporter) antibody was characterized by staining on the basal aspect of hagfish epidermis while Western blotting demonstrated greater expression of Rhcg in more posterior skin sections. We conclude that cutaneous Rhcg proteins are involved in cutaneous ammonia excretion by Pacific hagfish and that this mechanism could be particularly important during feeding., (Copyright © 2017 the American Physiological Society.)

Hagfishes, the most ancient of the extant craniates, demonstrate a high tolerance for a number of unfavorable environmental conditions, including elevated ammonia. Proposed mechanisms of ammonia excretion in aquatic organisms include vesicular NH(4)(+) transport and release by exocytosis in marine crabs, and passive NH(3) diffusion, active NH(4)(+) transport, and paracellular leakage of NH3 or NH(4)(+) across the gills of fishes. Recently, an emerging paradigm suggests that Rhesus glycoproteins play a vital role in ammonia transport in both aquatic invertebrates and vertebrates. This study has identified an Rh glycoprotein ortholog from the gills of Atlantic hagfish. The hagfish Rhcg shares a 56-60% amino acid identity to other vertebrate Rhcg cDNAs. Sequence information was used to produce an anti-hagfish Rhcg (hRhcg) antibody. We have used hRhcg to localize protein expression to epithelial cells of the gill and the skin. In addition, we have quantified hRhcg expression following exposure to elevated plasma ammonia levels. Animals exposed to a 3 mmol/kg NH(4)Cl load resulted in significantly elevated plasma ammonia concentrations compared with controls for up to 4 h postinjection. This correlated with net ammonia excretion rates that were also significantly elevated for up to 4 h postinjection. Rhcg mRNA expression in both the gill and skin was significantly elevated by 15 min and 1 h, respectively, and hRhcg protein expression in gills was significantly elevated at 2, 4, and 8 h postinjection. These results demonstrate a potential role for Rhcg in the excretion of ammonia in the Atlantic hagfish., (Copyright © 2015 the American Physiological Society.)

Modern hagfishes are considered to be the most primitive of the living craniates and along with their close jawless agnathan relative, the lamprey, take us back an astonishing 500 million years to the base of the vertebrate evolutionary tree. The unique osmoconforming strategy of the hagfish, whereby the osmotic constituents of the blood plasma bear more of a resemblance to marine invertebrates than vertebrates, has been classically depicted in comparative physiology textbooks for many years. Fifty years ago in this journal, Bellamy and Chester Jones [Bellamy and Chester Jones, 1961. CBP 3, 173-183] published a paper on the chemical composition of the tissues of the Atlantic hagfish, Myxine glutinosa. This publication was one of a flurry of papers published in the 50s, 60s and early 70s focused on describing the ionic and osmotic components of this bizarre fish. Here we take a retrospective look at the research that has taken place on these intriguing animals prior to and following the Bellamy and Chester Jones manuscript, focusing on tissue chemical compositions, the possible role of amino acids, and our current view on ion regulation, metabolism and hypoxia tolerance., (2010 Elsevier Inc. All rights reserved.)