Changing the perception of premenstrual dysphoric disorder - An online-experiment using the Stereotype Content Model.

Women with Premenstrual Dysphoric Disorder (PMDD) are often faced with prejudices about the premenstrual phase. The aim of this study was to investigate whether providing information (psychoeducation) could improve study participants' perception of a PMDD-patient and whether experimentally-induced prejudices about PMDD resulted in stigmatization. Two hundred sixteen students (50% female; aged 18-42 years) from Philipps University Marburg participated in January 2014. Participants were randomly assigned to one of two experimental groups (EG1, EG2) or to a control group (CG). EG1 read a text informing about PMDD. EG2 read a text with stereotypic PMDD-information. CG received a text with information unrelated to PMDD. Then, all participants watched a video of a woman reporting about her PMDD. Finally, participants appraised the woman on the cognitive dimensions warmth and competence as well as on PMDD-related attributes (depressive symptoms, emotional regulation). Participants of EG1 rated the woman as warmer (p <  .001), more competent (p =  .006), and with less depressive symptoms (p < .001) than the CG. The results by study group did not differ by gender. Stereotypic information did not differ significantly among the study groups. Psychoeducation can facilitate the understanding of PMDD-patients and should be integrated in future research on PMDD-treatments.

Cardiac arrest and sudden death in dialysis units.

BACKGROUND: For patients with end-stage renal disease and their providers, dialysis unit-based cardiac arrest is the most feared complication of hemodialysis. However, relatively little is known regarding its frequency or epidemiology, or whether a fraction of these events could be prevented. METHODS: To explore clinical correlates of dialysis unit-based cardiac arrest, 400 reported arrests over a nine-month period from October 1998 through June 1999 were reviewed in detail. Clinical characteristics of patients who suffered cardiac arrest were compared with a nationally representative cohort of> 77,000 hemodialysis patients dialyzed at Fresenius Medical Care North America-affiliated facilities. RESULTS: The cardiac arrest rate was 400 out of 5,744,708, corresponding to a rate of 7 per 100,000 hemodialysis sessions. Cardiac arrest was more frequent during Monday dialysis sessions than on other days of the week. Case patients were nearly twice as likely to have been dialyzed against a 0 or 1.0 mEq/L potassium dialysate on the day of cardiac arrest (17.1 vs. 8.8%). Patients who suffered a cardiac arrest were on average older (66.3 +/- 12.9 vs. 60.2 +/- 15.4 years), more likely to have diabetes (61.8 vs. 46.8%), and more likely to use a catheter for vascular access (34.1 vs. 27.8%) than the general hemodialysis population. Sixteen percent of patients experienced a drop in systolic pressure of 30 mm Hg or more prior to the arrest. Thirty-seven percent of patients who suffered cardiac arrest had been hospitalized within the past 30 days. Sixty percent of patients died within 48 hours of the arrest, including 13% while in the dialysis unit. CONCLUSIONS: Cardiac arrest is a relatively infrequent but devastating complication of hemodialysis. To reduce the risk of adverse cardiac events on hemodialysis, the dialysate prescription should be evaluated and modified on an ongoing basis, especially following hospitalization in high-risk patients.

Characterisation of the H(+)/peptide cotransporter of eel intestinal brush-border membranes.

H(+)/peptide cotransport in brush-border membrane vesicles (BBMVs) from eel (Anguilla anguilla) intestine was studied by measuring d-[(3)H]-phenylalanyl-l-alanine uptake and by monitoring peptide-dependent intravesicular acidification using the pH-sensitive dye Acridine Orange. d-[(3)H]-phenylalanyl-l-alanine influx was greatly stimulated by an inside-negative membrane potential and enhanced by an inwardly directed H(+) gradient. In parallel, vesicular H(+) influx was significantly increased in the presence of extravesicular d-phenylalanyl-l-alanine or a series of glycyl and l-prolyl peptides. H(+)/peptide cotransport displayed saturable kinetics involving a single carrier system with apparent substrate affinities of 0.9-2.6 mmol l(-1) depending on the particular peptide. All substrates tested competed with this system. Pre-incubation of BBMVs with dipeptides prevented diethylpyrocarbonate inhibition of transport activity, suggesting that the substrates mask histidine residues involved in the catalytic function of the transporter. Using human PepT1-specific primers, a reverse transcription-polymerase chain reaction (RT-PCR) signal was detected in eel intestine. Our results suggest that, in eel intestine, a brush-border membrane 'low-affinity'-type H(+)/peptide cotransport system is present that shares kinetic features with the mammalian intestinal PepT1-type transporters.

Regulation of the high-affinity H+/peptide cotransporter in renal LLC-PK1 cells.

Di- and tripeptides and peptide mimetics such as beta-lactam antibiotics are efficiently reabsorbed from the tubular lumen by a high-affinity peptide transporter. We have recently identified and characterized this H+-coupled high-affinity peptide transport system in the porcine proximal tubular cell line LLC-PK1. Here we describe for the first time the regulation of the renal high-affinity peptide cotransporter at the cellular level. Uptake of 5 microM 3H-D-Phe-L-Ala into LLC-PK1 cells was significantly increased by lowering [Ca2+]in and decreased by increasing [Ca2+] in. Moreover, it was shown that the [Ca2+]in effects on peptide transport activity were dependent on Ca2+ entry from the extracellular site (e.g., via a store-regulated capacitative Ca2+ influx). Protein kinase C (PKC) was found to transmit the effects of [Ca2+]in on peptide transport. Although we demonstrate by pHin measurements that the PKC inhibitor staurosporine did decrease the transmembrane H+ gradient and consequently should have reduced the driving force for peptide uptake, the only effect on transport kinetics of 3H-D-Phe-L-Ala observed was a significant decrease in Km from 22.7+/-2.5 microM to 10.2+/-1.9 microM with no change in maximal velocity.

Endogenous expression of the renal high-affinity H+-peptide cotransporter in LLC-PK1 cells.

The reabsorption of filtered di- and tripeptides as well as certain peptide mimetics from the tubular lumen into renal epithelial cells is mediated by an H+-coupled high-affinity transport process. Here we demonstrate for the first time H+-coupled uptake of dipeptides into the renal proximal tubule cell line LLC-PK1. Transport was assessed 1) by uptake studies using the radiolabeled dipeptide D-[3H]Phe-L-Ala, 2) by cellular accumulation of the fluorescent dipeptide D-Ala-Lys-AMCA, and 3) by measurement of intracellular pH (pHi) changes as a consequence of H+-coupled dipeptide transport. Uptake of D-Phe-L-Ala increased linearly over 11 days postconfluency and showed all the characteristics of the kidney cortex high-affinity peptide transporter, e.g., a pH optimum for transport of D-Phe-L-Ala of 6.0, an apparent Km value for influx of 25.8 +/- 3. 6 microM, and affinities of differently charged dipeptides or the beta-lactam antibiotic cefadroxil to the binding site in the range of 20-80 microM. pHi measurements established the peptide transporter to induce pronounced intracellular acidification in LLC-PK1 cells and confirm its postulated role as a cellular acid loader.

Cellular and molecular mechanisms of renal peptide transport.

Renal epithelial cells express membrane transport proteins capable of cellular uptake of a large variety of di- and tripeptides. These transporters contribute to renal amino acid homeostasis and the efficiency of conservation of amino acid nitrogen. In addition, these transporters appear to play a role in the renal handling of xenobiotics that possess a peptide backbone. Peptide carriers specialized in transport of di- and tripeptides have been identified in bacteria, fungi, plants, and epithelial cells of mammalian intestine and kidney. They appear to represent an archaic transporter family conserved throughout evolution. As a unique feature, these peptide carriers utilize a transmembrane-electrochemical proton gradient as the driving force that enables them to transport peptides against a concentration gradient. Renal peptide transporters have been characterized in terms of mechanism of transport function and substrate specificity in a number of model systems. Within the last two years, kidney peptide transporters of a variety of species have been identified by cloning techniques. In this review we discuss the physiological importance of renal peptide carriers and the transport mechanisms at the cellular level. We also present the recent advancements in functional expression of the cloned proteins that provide first insights into their molecular architecture and mode of operation.

Functional analysis of a chimeric mammalian peptide transporter derived from the intestinal and renal isoforms.

l. Recently two genes have been identified by expression cloning that encode mammalian epithelial peptide transporters capable of translocating di- and tripeptides and selected peptidomimetics by stereoselective and rheogenic substrate-H+ cotransport. PepT1 from rabbit or human small intestine induces a transport activity with high transport capacity but rather low substrate affinity when expressed in Xenopus oocytes. In contrast, the renal carrier PepT2 is a high affinity-type transporter with a lower maximal transport capacity. In addition, both transporters show differences in pH dependence and substrate specificity. 2. As a first approach to identify structural components of the transport proteins that determine their phenotypical characteristics, we constructed a recombinant chimeric peptide transporter (CH1Pep) in which the aminoterminal region (residues 1-401) is derived from PepT2 whereas the carboxyterminal region (residues 402-707) starting at the end of transmembrane domain 9 is derived from PepT1. Expression of PepT1, PepT2 and CH1Pep in Xenopus oocytes allowed the characteristics of the transporters to be determined by flux studies employing a radiolabelled dipeptide and by the two-electrode voltage clamp technique. 3. Our studies indicate that CH1Pep conserves the characteristics of PepT2 including the high affinity for dipeptides and peptidomimetics, the substrate specificity, the pH dependence of transport activation and the electrophysiological parameters. We conclude that the phenotypical characteristics of the renal peptide transporter are determined by its amino-terminal region.

Expression cloning and functional characterization of the kidney cortex high-affinity proton-coupled peptide transporter.

The presence of a proton-coupled electrogenic high-affinity peptide transporter in the apical membrane of tubular cells has been demonstrated by microperfusion studies and by use of brush border membrane vesicles. The transporter mediates tubular uptake of filtered di- and tripeptides and aminocephalosporin antibiotics. We have used expression cloning in Xenopus laevis oocytes for identification and characterization of the renal high-affinity peptide transporter. Injection of poly(A)+ RNA isolated from rabbit kidney cortex into oocytes resulted in expression of a pH-dependent transport activity for the aminocephalosporin antibiotic cefadroxil. After size fractionation of poly(A)+ RNA the transport activity was identified in the 3.0- to 5.0-kb fractions, which were used for construction of a cDNA library. The library was screened for expression of cefadroxil transport after injection of complementary RNA synthesized in vitro from different pools of clones. A single clone (rPepT2) was isolated that stimulated cefadroxil uptake into oocytes approximately 70-fold at a pH of 6.0. Kinetic analysis of cefadroxil uptake expressed by the transporter's complementary RNA showed a single saturable high-affinity transport system shared by dipeptides, tripeptides, and selected amino-beta-lactam antibiotics. Electrophysiological studies established that the transport activity is electrogenic and affected by membrane potential. Sequencing of the cDNA predicts a protein of 729 amino acids with 12 membrane-spanning domains. Although there is a significant amino acid sequence identity (47%) to the recently cloned peptide transporters from rabbit and human small intestine, the renal transporter shows distinct structural and functional differences.

Higher respiratory infection rates on an Alzheimer's special care unit and successful intervention.

OBJECTIVE: To determine the rates of various types of infections on an Alzheimer's special care unit (ASCU) compared with the rates found on traditional nursing home units. Because patients on the ASCUs are allowed to wander throughout the unit and typically come into contact with each other more frequently, we hypothesized that the rate of communicable infections such as upper respiratory infections are significantly higher than on other units where patients are more easily isolated when sick. METHODS: A 4-year retrospective case control study, 1990-1993. SETTING: A metropolitan long-term care skilled nursing facility. Three floors are traditional nursing care units (123 beds), and one floor is the ASCU (41 beds). PRIMARY OUTCOME: Annual nosocomial infection rates per 10,000 patient days were measured for six types of infection during the 1990-1993 study period. Data were segregated by location of infection, either the traditional nursing units or the ASCU. In 1992, patients on the Alzheimer's unit were placed in smaller activity groups, and an education program for the control of infectious agents was provided to the unit's staff. RESULTS: The relative order of prevalence for the different infection types remained constant during the 4 years. The most common type of infection for all 4 years of the study period was urinary tract infection (UTI), followed by upper respiratory infection (URI), Lower respiratory tract infection (LRI), cutaneous infection, gastrointestinal (GI) infection, and eye infection. Of these various infections, only URI rates remained consistently higher on the ASCU versus the traditional nursing unit over the 4-year study period (in years 1990, 1991, and 1993; these differences were statistically significant, P < .05). In 1992, the year in which nursing interventions to curb the relatively high rates of URI on the ASCU took place, the rates of URI on the two unit types were not statistically different. CONCLUSIONS: This study suggests that an inherent risk of ASCUs is an increased exposure to highly contagious infections such as upper respiratory infections. An intervention program effective in decreasing this risk to the level of traditional nursing units is proposed. A prospective study is needed to confirm these findings.

A temperature-sensitive mutation in the acidic polymerase gene of an influenza A virus alters the regulation of viral protein synthesis.

The temperature-sensitive defect of mutant ts 263 of fowl plague virus (FPV) is located in the acidic polymerase (PA) gene and is due to a single base substitution (C2036T), which leads to an amino acid replacement (Ala671 to Val) in a highly conserved region of the protein. During passage at 33 degrees C ts 263 stably carries over a ninth RNA segment, which consists of a truncated PA gene. Although the deletion is in-frame and it is transcribed into mRNA, no corresponding protein is detected in vivo. After reversion to wild-type this extra RNA segment is immediately lost. At the non-permissive temperature of 40 degrees C no significant viral products of ts 263 are synthesized. Under semi-permissive conditions there is a relative, but very significant over-production of the M1 protein, which is not accompanied by a corresponding elevated M1 mRNA synthesis. These results are in agreement with the idea that the PA protein is involved in the regulation of viral protein synthesis at the level of expression of mRNA. Preinfection of chicken embryo cells with ts 263 at a semi-permissive temperature interferes with the replication of FPV wild-type indicating that premature availability of M1 might be detrimental for influenza virus replication.

Outcomes of systemic/strategic team consultation: III. The importance of therapist warmth and active structuring.

This is the third in a series of reports on a small-sample study of systemic/strategic team consultations. It sheds new light on aspects of the therapeutic alliance in Milan-informed therapy. Ratings of the end-of-session interventions and ratings of the therapist's relationship skills (warmth, active structuring) significantly predicted client improvement at 1-month and 3-year followups. These results dispute the Milan team's idea that an intervention's effects are unpredictable. Also, our findings challenge the way some teams have adopted an impersonal, emotionally unresponsive style under the guise of "neutrality." In view of this and other recent studies, we conclude that systemic/strategic therapists should devote more attention to collaborative and affective qualities of the therapeutic alliance.

Outcomes of systemic/strategic team consultation: II. Three-year followup and a theory of "emergent design".

This is the second in a series of articles on an experimental, small-sample study of systemic/strategic team consultations. It presents the 3-year outcomes of clients whose 1-month progress was described in an earlier report (12). The 8 therapists in the current study originally were asked to select two ongoing cases matched for difficulty (N = 16). While all cases continued their regular therapy sessions, one of each therapist's two cases were selected at random to participate in a "Milan-informed," five-part team consultation. At 3-year followup, clients who participated in team consultations had maintained significantly higher levels of goal attainment than nonteam clients (p less than .05). For interpreting these results, we propose a developmental theory ("emergent design") to explain therapy impasses, team effects, the impact of termination, and long-range outcomes of therapy.

Outcomes of systemic/strategic team consultation: I. Overview and one-month results.

This is the first in a series of reports on an experimental, small-sample study of systemic/strategic team consultations. This report describes a "Milan-informed" method of team consultation for resolving therapy impasses. It then focuses on the initial one-month outcomes from the larger 3-year project. Eleven therapists were asked to select two ongoing cases matched for difficulty. While all cases continued in regular therapy, one of each therapist's cases was also selected at random to participate in a systemic/strategic, five-part team consultation. Analyses of one-month follow-up data showed that clients who participated in the team consultation were more likely to achieve their main and overall treatment goals than clients who received only regular therapy (p's less than .05, eta2 as a measure of effect size ranging from 32% to 41%). The strong findings of this initial study encourage more widespread use of team consultations as a context for treatment, training, and research.