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C. maenas, an osmotic and ionic conformer at high salinity (32 - 40 ppt), makes a transition to osmotic and ionic regulation at 10 ppt; hemolymph concentrations stabilize by 6 - 12 h at values significantly above those in the medium Carbonic anhydrase (CA) activity, which is low and uniformly distributed across all gills at 32 ppt, is induced 7 fold in gills 6 - 9. Induction is initiated at 4 days post-transfer and is complete by 7-14 days. CA inhibition by acetazolamide causes decreased hemolymph osmotic and ionic concentrations at 10 but not 32 ppt. Branchial Na/K ATPase activity is low in all gills at 40 ppt but is induced in G6 - 9 at 32 ppt and does not increase at 10 ppt. High Na/K ATPase values may be related to the crab's intertidal habitat in which rapid and unpredictable dilutions can occur. Supported by NSF 97-27835 and by the Salsbury Cove Research Foundation.

In euryhaline crabs, ion-transporting cells are clustered into osmoregulatory patches on the lamellae of the posterior gills. To examine changes in the branchial osmoregulatory patch in the blue crab Callinectes sapidus in response to change in salinity and to correlate these changes with other osmoregulatory responses, crabs were acclimated to a range of salinities between 10 and 35 ppt. When crabs that had been acclimated to 35 ppt were subsequently transferred to 10 ppt, both the size of the osmoregulatory patch on individual gill lamellae and the specific activity of Na+, K+-ATPase in whole-gill homogenatas increased only after the first 24 h of exposure to dilute seawater. Enzyme activity and size of patch area increased gradually and reached their maxima (increasing by 200% and 60%, respectively) 6 days following transfer to 10 ppt seawater and then remained at these levels. Patch size at acclimation varied inversely with the salinity for seawater dilutions below 26 ppt (the isosmotic point of the crab), although it did not vary in salinities at or above 26 ppt. Thus, the size of the patch clearly is modulated with acclimation salinity, but it increases only in those salinities in which the crab hyperosmoregulates. An increase in the total RNA/DNA ratio in gill homogenates, the lack of mitotic figures in the lamellae, and the lack of incorporation of bromodeoxyuridine into nuclei of lamellar epithelial cells during acclimation to dilute seawater were interpreted as evidence that no cell proliferation had occurred and that increases in the size of the osmoregulatory patch occurred through differentiation of existing gas exchange cells or of undifferentiated epithelial cells into ion-transporting cells. [ABSTRACT FROM AUTHOR]

Hemocyanin, the blue blood protein of many arthropods and molluscs, reversibly binds oxygen at its highly conserved copper-oxygen-binding sites and supplies tissues with oxygen. Cryptocyanin, closely related structurally and phylogenetically to arthropod hemocyanin, lacks several of the six critical copper-binding histidines, however, and has lost the ability to bind oxygen. Despite this loss of function, cryptocyanin continues to be synthesized, an indication that it has been exploited to carry out new functions. Here, we show that cryptocyanin is present in extremely high concentrations in the hemolymph of the crab during the premolt portion of the molt cycle. Both proteins are specifically expressed in the same type of cell in the hepatopancreas and secreted into the hemolymph, but cryptocyanin plays a major role in forming the new exoskeleton, while hemocyanin functions in oxygen transport. A cessation in cryptocyanin, but not hemocyanin, synthesis after eyestalk ablation supports our hypothesis that cryptocyanin is closely regulated by molting hormones. The contrasts between the two gene products illustrate how a gene duplication of a copper-oxygen protein and its subsequent mutation may work in concert with the evolution of new regulatory mechanisms, leading to the assumption of new functions. [ABSTRACT FROM AUTHOR]

OBJECTIVE To compare the provision of health and social services between a social work intervention and non-intervention group. DESIGN Depressed stroke patients were randomly assigned to either an intervention or non-intervention group. Over a 4 month period both groups were visited three times by an independent assessor who rated them on service provision and functional independence. SETTING Patients' homes. PATIENTS 44 depressed stroke patients. INTERVENTION Both groups were given an information booklet and the intervention group were then visited regularly by a research social worker over a period of 4 months. The social worker adopted a pragmatic approach which included providing counselling and information on services and benefits. MAIN RESULTS The study groups did not differ in level of social independence (p greater than 0.05) or total number of financial benefits (p greater than 0.05), services (p greater than 0.05) or aids (p greater than 0.05) received either before or after intervention. When the results from the two groups were combined, home help and meals-on-wheels were the most frequently provided services (25% of patients). Walking aids (72% of patients) and bath aids (59% of patients) were the most frequently provided aids to daily living. CONCLUSION Social work assistance had little effect on service provision or level of functional independence. [ABSTRACT FROM AUTHOR]

This paper reports the results of measurements of the attenuation and velocity of ultrasonic waves in various liquid media as a function of the intensity level at the detector of the radiation. The attenuation in distilled water and dilute solutions of acetic acid and sodium acetate is found to increase almost linearly with the acoustic excess pressure amplitude in the range from 2 to 7 atmospheres, for frequencies of 4, 5, 7, and 9 megacycles/sec. The attenuation in glycerine shows a similar increase when correction is made for the unavoidable rise in temperature of the medium. The rate of increase is found to be practically independent of frequency in the range employed, thus disagreeing with the prediction of R. D. Fay's theory of the attenuation of high-amplitude plane waves. No change of velocity with source intensity has been observed. [ABSTRACT FROM AUTHOR]

Audience: This classic team-based learning activity is specifically designed for emergency medicine bound medical students and junior residents; however, general pediatrics residents and general medical students may also benefit from this activity. Senior residents and fellows felt that the cases were too basic for them but enjoyed acting as facilitators., Introduction/background: Vomiting is a common chief complaint in pediatric patients seen in the Emergency Department. 1-3 Presentations include acute, chronic, and cyclic vomiting, with underlying etiologies such as toxin injection, emotional disturbances, and movement disequilibrium. 1 By understanding these various pathways, it is helpful for physicians to distinguish between gastrointestinal and non-gastrointestinal causes of vomiting. 1 Most cases of vomiting in the pediatric population are self-limiting and require only supportive treatment; however, physicians must be able to recognize red flags associated with vomiting that warrant further evaluation. 1,3 This task may be challenging for medical students and residents in emergency medicine and those with infrequent exposure to pediatric patients. Therefore, this team-based learning activity was developed to help junior learners in differentiating non-emergent and emergent cases of pediatric vomiting. This activity aids learners in formulating a differential based on age, history, and characteristics of vomiting. We also review specific causes of pediatric vomiting that physicians cannot miss including intussusception, pyloric stenosis, malrotation, intestinal atresia, and intracranial pathology., Educational Objectives: By the end of this TBL session, learners should be able to:Identify red flag symptoms that should prompt referral for urgent intervention by GI or surgical specialists.Recognize how chronicity of the vomiting can alter the differential diagnosisDescribe the varying pathways that can cause nausea and vomiting.Determine the necessity of imaging tests to confirm and possibly treat various causes of vomiting.Interpret imaging studies associated with specific causes of vomiting., Educational Methods: Classic Team Based Learning (cTBL)., Research Methods: Learners and instructors provided verbal feedback after the session in a large group format. Learners were specifically asked if they felt the session was education, relevant, high-yield and level appropriate. One instructor provided written feedback to the cases as well., Results: Overall learners and instructors found the session to be engaging, informative and educational. Learners felt that the session was level appropriate for medical students and junior residents. As a result of feedback from the session, several of the iRAT/gRAT questions were adjusted and the group application cases were re-written and implemented., Discussion: Overall, the educational content and delivery was effective. This session was presented to a group of emergency medicine students, interns and residents. Learners were divided into smaller groups, and each group had a variety of level of learners, including pediatric emergency medicine fellows, present. The fellows, while not necessary to the delivery of the TBL, were extremely helpful in aiding the residents during the session. The final debriefing and answer review were essential to ensure that learners met all educational objectives and fully understood the materials., Topics: Pediatric vomiting, intussusception, pyloric stenosis, intestinal atresia, malrotation, gastroesophageal reflux disease, superior mesenteric artery (SMA) syndrome, hyperemesis., (© 2020 Wray, et al.)

Outbreaks and pseudo-outbreaks of infection related to bronchoscopy typically involve Gram-negative bacteria, Mycobacterium species or Legionella species. We report an unusual bronchoscopy-related pseudo-outbreak due to Actinomyces graevenitzii. Extensive epidemiological and microbiological investigation failed to identify a common source. Strain typing revealed that the cluster was comprised of heterogeneous strains of A. graevenitzii. A change in laboratory procedures for Actinomyces cultures was coincident with the emergence of the pseudo-outbreak, and we determined that A. graevenitzii isolates more readily adopted a white, dry, molar tooth appearance on anaerobic colistin nalidixic acid (CNA) agar which likely facilitated its detection and identification in bronchoscopic specimens. This unusual pseudo-outbreak was related to frequent requests of bronchoscopists for Actinomyces cultures combined with a change in microbiology laboratory practices., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Background: Contaminated nebulizers are a potential source of bacterial infection but no single method is universally accepted for disinfection. We hypothesized that baby-bottle steam sterilizers effectively disinfect home nebulizers., Methods: Home nebulizers were inoculated with the common CF respiratory pathogens methicillin resistant Staphylococcus aureus, Burkholderia cepacia, Haemophilus influenzae, mucoid and non mucoid Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The nebulizers were swabbed for bacterial growth, treated with either the AVENT (Philips), the NUK Quick & Ready (Gerber) or DRY-POD (Camera Baby) baby bottle steam sterilizer and reswabbed for bacterial growth., Results: All steam sterilizers were effective at disinfecting all home nebulizers. Viable bacteria were not recovered from any inoculated site after steam treatment, under any conditions tested., Conclusions: Steam treatment is an effective disinfection method. Additional studies are needed to confirm whether these results are applicable to the clinical setting., (Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Unfolded epipodite isolated from American lobsters (Homarus americanus) acclimated to dilute seawater was mounted in an Ussing-type chamber for ion transport studies. The split epipodite is an electrically polarized, one-cell-layer epithelium supported with cuticle. Under open-circuit conditions, the transepithelial potential was -4.2+/-1.0 mV (N=38). In the short-circuited epithelium, the current averaged over all of the preparations was -185.4+/-20.2 A cm(-2) (N=38) with a high conductance of 55.2+/-11.4 mS cm(-2) (N=38), typical for a leaky epithelium. The Na:Cl absorptive flux ratio was 1:1.6; ion substitution experiments indicated that the transport of Na+ and Cl- is coupled. Basolateral application of the Cl- channel blockers 5-nitro-2-(3-phenylpropylamino) benzoate (NPPB) and niflumic acid (NFA) dose-dependently inhibited short-circuit current (ISC). Secretory K+ (Rb+) fluxes exceeded influxes and were inhibited by the Na+/K+-ATPase inhibitor ouabain and the K+ channel blocker cesium. Western blot analysis showed that Na+/K+-ATPase alpha-subunit protein was more highly expressed in the epipodite of lobsters acclimated to 20 p.p.t. compared with animals acclimated to seawater (34 p.p.t.). 3-Isobutyl-1-methyl-xanthine (IBMX) stimulated a negative ISC and enhanced apical secretory K+ flux. Basolateral application of NPPB inhibited JRbB-->A fluxes, suggesting the interaction of K+ channels with NPPB-sensitive Cl- channels. The results are summarized in a transport model, suggesting apical Na+/K+/2Cl- co-transport, a dominant apical K+-secreting channel and basolaterally located Cl- and K+ channels. This study represents the first comprehensive characterization of ion transport processes across the lobster epipodite epithelium and indeed in any tissue within the branchial cavity of the American lobster.

pQDLDHVFLRFamide is a highly conserved crustacean neuropeptide with a structure that places it within the myosuppressin subfamily of the FMRFamide-like peptides. Despite its apparent ubiquitous conservation in decapod crustaceans, the paracrine and/or endocrine roles played by pQDLDHVFLRFamide remain largely unknown. We have examined the actions of this peptide on the cardiac neuromuscular system of the American lobster Homarus americanus using four preparations: the intact animal, the heart in vitro, the isolated cardiac ganglion (CG), and a stimulated heart muscle preparation. In the intact animal, injection of myosuppressin caused a decrease in heartbeat frequency. Perfusion of the in vitro heart with pQDLDHVFLRFamide elicited a decrease in the frequency and an increase in the amplitude of heart contractions. In the isolated CG, myosuppressin induced a hyperpolarization of the resting membrane potential of cardiac motor neurons and a decrease in the cycle frequency of their bursting. In the stimulated heart muscle preparation, pQDLDHVFLRFamide increased the amplitude of the induced contractions, suggesting that myosuppressin modulates not only the CG, but also peripheral sites. For at least the in vitro heart and the isolated CG, the effects of myosuppressin were dose-dependent (10(-9) to 10(-6) mol l(-1) tested), with threshold concentrations (10(-8)-10(-7) mol l(-1)) consistent with the peptide serving as a circulating hormone. Although cycle frequency, a parameter directly determined by the CG, consistently decreased when pQDLDHVFLRFamide was applied to all preparation types, the magnitudes of this decrease differed, suggesting the possibility that, because myosuppressin modulates the CG and the periphery, it also alters peripheral feedback to the CG.

Hemocyanin, the blue blood protein of many arthropods and molluscs, reversibly binds oxygen at its highly conserved copper-oxygen-binding sites and supplies tissues with oxygen. Cryptocyanin, closely related structurally and phylogenetically to arthropod hemocyanin, lacks several of the six critical copper-binding histidines, however, and has lost the ability to bind oxygen. Despite this loss of function, cryptocyanin continues to be synthesized, an indication that it has been exploited to carry out new functions. Here, we show that cryptocyanin is present in extremely high concentrations in the hemolymph of the crab during the premolt portion of the molt cycle. Both proteins are specifically expressed in the same type of cell in the hepatopancreas and secreted into the hemolymph, but cryptocyanin plays a major role in forming the new exoskeleton, while hemocyanin functions in oxygen transport. A cessation in cryptocyanin, but not hemocyanin, synthesis after eyestalk ablation supports our hypothesis that cryptocyanin is closely regulated by molting hormones. The contrasts between the two gene products illustrate how a gene duplication of a copper-oxygen protein and its subsequent mutation may work in concert with the evolution of new regulatory mechanisms, leading to the assumption of new functions.

Many studies have shown that hyperosmoregulation in euryhaline crabs is accompanied by enhanced Na(+)+K(+)-ATPase activity in the posterior gills, but it remains unclear whether the response is due to regulation of pre-existing enzyme or to increased gene transcription and mRNA translation. To address this question, the complete open reading frame and 3' and 5' untranslated regions of the mRNA coding for the alpha-subunit of Na(+)+K(+)-ATPase from the blue crab Callinectes sapidus were amplified by reverse transcriptase/polymerase chain reaction (RT-PCR) and sequenced. The resulting 3828-nucleotide cDNA encodes a putative 1039-amino-acid protein with a predicted molecular mass of 115.6 kDa. Hydrophobicity analysis of the amino acid sequence indicated eight membrane-spanning regions, in agreement with previously suggested topologies. The alpha-subunit amino acid sequence is highly conserved among species, with the blue crab sequence showing 81-83 % identity to those of other arthropods and 74-77 % identity to those of vertebrate species. Quantitative RT-PCR analysis showed high levels of alpha-subunit mRNA in posterior gills 6-8 compared with anterior gills 3-5. Western blots of gill plasma membranes revealed a single Na(+)+K(+)-ATPase alpha-subunit protein band of the expected size. The posterior gills contained a much higher level of alpha-subunit protein than the anterior gills, in agreement with previous measurements of enzyme activity. Immunocytochemical analysis showed that the Na(+)+K(+)-ATPase alpha-subunit protein detected by alpha5 antibody is localized to the basolateral membrane region of gill epithelial cells. Transfer of blue crabs from 35 to 5 per thousand salinity was not accompanied by notable differences in the relative proportions of alpha-subunit mRNA and protein in the posterior gills, suggesting that the enhanced Na(+)+K(+)-ATPase enzyme activity that accompanies the hyperosmoregulatory response may result from post-translational regulatory processes.

The vacuolar-type H(+)-ATPase (V-ATPase) has been implicated in osmoregulatory ion uptake across external epithelia of a growing variety of species adapted to life in fresh water. In the present study, we investigated whether the V-ATPase may also function in a euryhaline species that tolerates brackish water (8 salinity) but not fresh water, the shore crab Carcinus maenas. cDNA coding for the regulatory B-subunit of the V-ATPase was amplified and sequenced from C. maenas gills and partially sequenced from four other crab species. Two isoforms differing in the 3'-untranslated region were found in C. maenas. In this species, the abundance of B-subunit mRNA was greater in the respiratory anterior gills than the ion-transporting posterior gills and was not increased by acclimation to dilute salinity. Immunocytochemical analysis showed that the B-subunit protein is not targeted to the apical membrane but is distributed throughout the cytoplasmic compartment. Physiological studies of isolated perfused gills indicated that the V-ATPase inhibitor bafilomycin had no effect on transepithelial potential difference. Thus, in contrast to the freshwater-tolerant Chinese crab Eriocheir sinensis, in which the V-ATPase appears to play an important osmoregulatory role, the V-ATPase in C. maenas probably functions in acidification of intracellular organelles but not in transbranchial NaCl uptake.

Phosphagen kinases catalyze the reversible dephosphorylation of guanidino phosphagens such as phosphocreatine and phosphoarginine, contributing to the restoration of adenosine triphosphate concentrations in cells experiencing high and variable demands on their reserves of high-energy phosphates. The major invertebrate phosphagen kinase, arginine kinase, is expressed in the gills of two species of euryhaline crabs, the blue crab Callinectes sapidus and the shore crab Carcinus maenas, in which energy-requiring functions include monovalent ion transport, acid-base balance, nitrogen excretion and gas exchange. The enzymatic activity of arginine kinase approximately doubles in the ion-transporting gills of C. sapidus, a strong osmoregulator, when the crabs are transferred from high to low salinity, but does not change in C. maenas, a more modest osmoregulator. Amplification and sequencing of arginine kinase cDNA from both species, accomplished by reverse transcription of gill mRNA and the polymerase chain reaction, revealed an open reading frame coding for a 357-amino-acid protein. The predicted amino acid sequences showed a minimum of 75 % identity with arginine kinase sequences of other arthropods. Ten of the 11 amino acid residues believed to participate in arginine binding are completely conserved among the arthropod sequences analyzed. An estimation of arginine kinase mRNA abundance indicated that acclimation salinity has no effect on arginine kinase gene transcription. Thus, the observed enhancement of enzyme activity in C. sapidus probably results from altered translation rates or direct activation of pre-existing enzyme protein.