bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of nurses’ sex‐role orientation on positive and negative assertion
Authors: J McCartan Patrick , Hargie Owen
Published: February 2004

The present paper examines how the sex‐role orientation of the nurse can affect both positive and negative assertion. The Bem Sex‐Role Inventory (BRSI) and the Assertion Inventory (AI) were used to collect self‐reported data from a convenience sample of 94 subjects. Behavioral data were obtained by directly sampling 50 nurses’ responses within role‐play situations. Contrary to earlier studies, the findings of the investigation indicated that there was no significant relationship between assertion measurements and sex‐role orientation. Following a discussion of the findings, recommendations relating to future research are made and the limitations of the study are identified.
Characteristics of primary nocturnal enuresis in adults: an epidemiological study
Authors: Yeung C.K. , Sihoe J.D.Y. , Sit F.K.Y. , Bower W. , Sreedhar B. , Lau J.
Published: February 2004

OBJECTIVE

To evaluate the prevalence and characteristics of primary nocturnal enuresis (PNE) in adults in Hong Kong, as there are currently limited epidemiological data in adults.

SUBJECTS AND METHODS

After a telephone survey, 8534 respondents (3996 males and 4538 females) aged 16–40 years were selected for the study and stratified in age groups. The questionnaire used comprised two parts; the first started with questions mainly about the general demographic background to decrease the sensitivity of the study and to establish rapport. The second part was conducted through an automated telephone interview service, with the questions being asked by recorded messages and the respondents then keying in their responses with no need to converse with an interviewer. This part included questions about enuretic symptoms and a subjective assessment of social and psychological effects of bedwetting, and measurements of the individual's self‐esteem (Rosenberg Self‐esteem Scale) and depression (The Centre for Epidemiological Studies Depression Scale).

RESULTS

Of the 8534 subjects interviewed, 196 had PNE, giving an overall prevalence of 2.3% (2.7% males and 2.0% females); of these 196, 36 (18.4%) also had daytime urinary incontinence. Hence, 1.9% of adults (2.2% males and 1.7% females) had monosymptomatic PNE. Of these, 53% wet > 3 nights/week and 26% wet every night. Prevalence rates remained relatively stable among different age groups, with no apparent trend of a reduction with age. Compared with nonenuretic normal controls, significantly fewer enuretics reached tertiary education (33.4% vs 17.8%, P < 0.01). Bedwetters had a significantly higher incidence of depression and lower self‐esteem, and a higher incidence of sleep disturbances than the control group. Among bedwetters, 32–40% felt that there was some effect on their choice of job, work performance and social activities, whilst 23% felt the condition affected their family life and in making friends of either sex. However, there was no significant difference in the marital status. Interestingly, only 34.5% of females and half of males used various methods before bedtime to prevent bedwetting.

CONCLUSIONS

Overall, 2.3% of Hong Kong adults aged 16–40 years have persistent PNE. Unlike PNE in early childhood the prevalence remained relatively unchanged with age, suggesting that enuretic symptoms persisting into adulthood are probably less likely to resolve with time. Also, significantly more patients had more severe enuretic symptoms. These findings therefore highlight the possibility that PNE in adults may represent a more pronounced form of the condition, and with a more serious social and psychological effect on affected individuals. Further work is needed to evaluate the pathogenesis and management strategy.
Prostate apoptosis after doxazosin treatment in the spontaneous hypertensive rat model
Authors: Lujan M. , Ferruelo A. , Paez A. , Moreno A. , Berenguer A.
Published: February 2004

OBJECTIVE

To validate the spontaneous hypertensive rat (SHR) model for basic research into benign prostate hyperplasia (BPH), and to assess doxazosin‐induced changes in prostatic structure and apoptotic status.

MATERIALS AND METHODS

Four groups of rats were assessed: group 1, 15 SHRs treated with doxazosin; group 2, 14 SHRs with unilateral excision of the major pelvic ganglion; group 3, 14 untreated SHRs; and group 4, 16 intact Wistar‐Kyoto (WKY) rats. The doxazosin mesylate (0.03 mg daily) was given compacted in rat food for 3 months. The prostatic ventral lobe (VL) was excised and weighed. Stereological light microscopy, multiplex reverse transcription‐polymerase chain reaction of prostate caspases, and caspase‐3 activity (cellular enzymatic assay) were assessed.

RESULTS

There was more development of the glandular epithelium (P < 0.001) in SHR rats than in controls, which was even greater after doxazosin exposure (P = 0.027). SHR animals had higher caspase expression (P < 0.05) and activity (P = 0.008) than WKY rats, but both were reduced after doxazosin therapy (P < 0.01 and 0.028, respectively).

CONCLUSIONS

This study confirmed prostate hyperplasia in the SHR model. Doxazosin exposure did not reduce the volume of glandular epithelium and contributed to protecting against caspase‐induced apoptosis. The SHR model may be not a valid option to study doxazosin‐induced apoptosis in BPH.
Effects of acupuncture and care interventions on the outcome of inflammatory symptoms of the breast in lactating women
Authors: Kvist L. J. , Wilde Larsson B. , Hall‐Lord M. L. , Rydhstroem H.
Published: February 2004

Objective: To compare modes of care and treatment for lactating women with inflammatory symptoms of the breast, with special focus on the use of acupuncture. Method: Eighty‐eight mothers were randomized into three treatment groups. All three groups were given advice regarding emptying of the breasts and care in the form of comfort interventions. Acupuncture was included in the treatment regime for two of the groups. A severity index was created by adding together scores for signs and symptoms: breast tension, erythema and pain. Findings: Mothers in all groups expressed relative satisfaction with the breastfeeding situation despite considerable discomfort. There was no significant difference between the groups for the number of mothers requiring more than three contact days for recovery nor for their severity index scores on day 3. These findings must be interpreted with care but may suggest that care interventions play as great a part in the recovery of these women as acupuncture treatment or the use of oxytocin spray. Antibiotic therapy was used in 9% of the study population, which is in contrast to other studies. Proposed future action: Based on these results, a new study has been designed to test the hypothesis that acupuncture hastens recovery from inflammatory processes in the lactating breast and approximately 200 mothers will be randomized in a new expanded study.
A review of the literature on care of clients in pain who are culturally diverse
Authors: Davidhizar R. , Giger J. N.
Published: February 2004

Aim: This article reviews the literature on the care of clients from diverse cultures who are in pain and provides strategies for care.Background: Pain is a critical concept for caring for clients and particularly for clients from another culture. Culture shapes the values, beliefs, norms, and practices of individuals, including the ways persons react to pain. Culture affects the assessment and management of pain.Conclusions: Seven strategies can assist in culturally appropriate assessment and management of pain: (1) utilize assessment tools to assist in measuring pain, (2) appreciate variations in affective response to pain, (3) be sensitive to variations in communication styles, (4) recognize that communication of pain may not be acceptable within a culture, (5) appreciate that the meaning of pain varies between cultures, (6) utilize knowledge of biological variations, and (7) develop personal awareness of values and beliefs which may affect responses to pain.
Adolescents’ views on decision‐making regarding risky sexual behaviour
Authors: Zwane I. T. , Mngadi P. T. , Nxumalo M. P.
Published: February 2004

Purpose: To explore adolescents’ views regarding risky sexual behaviour who were aged between 13 and 19 years. Method: A purposive sample was drawn from adolescents who were participating in workshops, organized by the Ministry of Health and Social Welfare. The sample consisted of a mix of in‐school and out‐of‐school adolescents aged between 13 and 19 years. The overall aim of the workshops was to explore adolescents’ views on decision‐making regarding risky sexual behaviour. The educational status of participants lay between grades 0 and 12. A total of 24 focus group discussions were conducted, six in each of the four regions of Swaziland (Manzini, Hhohho, Lubombo and Shiselweni). Each group consisted of 6–12 participants. All focus group discussions were audiotaped and later transcribed. Findings: The following four major themes emerged from content analysis: sexual behaviour, age at first intercourse, peer pressure and trust in the relationship. These were all found to be important factors in decision‐making for risky sexual behaviours. Conclusion: Obtaining a sexual history, motivation to use condoms, guidance and counselling on ways to reduce adolescents’ risk of sexual exploitation, and peer education programmes, are all of importance when aiming to reduce risky sexual behaviour. Recommendation: Adolescents should receive positive reinforcement for responsible sexual behaviour including abstinence and, where appropriate, use of active birth control.
Adult Attachment, Parent Emotion, and Observed Parenting Behavior: Mediator and Moderator Models
Authors: Adam Emma K. , Gunnar Megan R. , Tanaka Akiko
Published: February 2004

In a middle‐class sample of mothers of 2‐year‐olds, adult attachment classifications measured in the Adult Attachment Interview (AAI) were related to maternal self‐reported emotional well‐being and observed parenting behavior, and the potential mediating and moderating roles of maternal emotion were tested. Mothers classified as dismissing on the AAI reported significantly lower levels of positive affectivity. Mothers classified as preoccupied reported significantly higher levels of negative affectivity and anxiety. Preoccupied mothers were observed to be significantly higher on angry/intrusive parenting, but this association was not mediated by attachment‐related differences in maternal emotion. Maternal emotional well‐being did, however, moderate the associations between adult attachment and parenting behavior: Dismissing attachment was significantly associated with lower warmth/responsiveness only among mothers with higher levels of depressive symptoms.
Parental Perceived Control Over Caregiving and Its Relationship to Parent–Infant Interaction
Authors: Guzell Jacqueline R. , Vernon‐Feagans Lynne
Published: February 2004

In this sample of 66 dual‐earner mothers and fathers and their 1‐year‐old infants, associations among parental ratings of infant difficulty, parental perceived control over caregiving outcomes, and parental sensitive and directive behavior were examined during a triadic free‐play session in the home. Perceived infant difficulty was related to maternal directiveness for mothers with low perceived control. Fathers with low perceived control exhibited more directiveness, regardless of their ratings of infant difficulty. For both mothers and fathers, there was a negative association between sensitivity and directiveness but no association between sensitive behavior and parental perceived control. Although parents scored similarly overall on various other measures, mothers with low perceived control demonstrated more categorical thinking about children's development than other mothers.
Japanese Mothers' Views of Young Children's Areas of Personal Discretion
Authors: Yamada Hiroyuki
Published: February 2004

Sixty‐four Japanese mothers of 3‐ to 6‐year‐olds were interviewed concerning their conceptions of children's areas of personal control. Mothers granted children choices regarding recreational activities, clothes, and friends to foster autonomy and competence, but they set limits around daily routines, recreational activities, and interpersonal confrontation based on moral, conventional, and prudential concerns. Mothers believed in reaffirming children's personal boundaries when children failed to follow through with their initial decisions. Mothers experienced conflict with children around daily routines and recreational activities and used various resolution strategies. Mothers perceived child resistance as egocentric whereas fewer considered it as establishing personal boundaries. Some age and gender differences were observed. Results supported the heterogeneity of social judgments and practices of individuals within cultures.
Sibling Conflict and Ineffective Parenting as Predictors of Adolescent Boys' Antisocial Behavior and Peer Difficulties: Additive and Interactional Effects
Authors: Bank Lew , Burraston Bert , Snyder Jim
Published: February 2004

Extensive sibling conflict is predictive of multiple poor adjustment outcomes during adolescence and early adulthood, but the frequency and developmental impact of such conflict may be conditional on ineffective parenting. Thus, sibling conflict may add to or amplify the negative effects of ineffective parenting on adolescent boys' adjustment. Hypotheses in this study were that: (a) multiple informant measures of problematic parent–child relationships and of sibling conflict would form distinct constructs rather than a single negative family process construct, and (b) ineffective parenting, sibling conflict, and their interaction measured at ages 10 to 12 would predict boys' concurrent status and developmental trajectories for antisocial behavior and peer adjustment across a 4‐year span from ages 12 to 16. Confirmatory factor and latent growth modeling analyses were consistent with these hypotheses, demonstrating the important developmental impact of sibling conflict.
Molecular Characterization of a High-Affinity Xylobiose Transporter of
Streptomyces thermoviolaceus
OPC-520 and Its Transcriptional Regulation
Authors: Tsujibo Hiroshi , Kosaka Mitsuo , Ikenishi Sadao , Sato Takaji , Miyamoto Katsushiro , Inamori Yoshihiko
Published: February 2004

Streptomyces thermoviolaceus
OPC-520 secretes two types of xylanases (StxI and StxII), an acetyl xylan esterase (StxIII), and an α-
l
-arabinofuranosidase (StxIV) in the presence of xylan. Xylan degradation products (mainly xylobiose) produced by the action of these enzymes entered the cell and were then degraded to xylose by an intracellular β-xylosidase (BxlA). A gene cluster involved in xylanolytic system of the strain was cloned and sequenced upstream of and including a BxlA-encoding gene (
bxlA
). The gene cluster consisted of four different open reading frames organized in the order
bxlE
,
bxlF
,
bxlG
, and
bxlA
. Reverse transcriptase PCR analysis revealed that the gene cluster is transcribed as polycistronic mRNA. The deduced gene products, comprising BxlE (a sugar-binding lipoprotein), BxlF (an integral membrane protein), and BxlG (an integral membrane protein), showed similarity to components of the bacterial ATP-binding cassette (ABC) transport system; however, the gene for the ATP binding protein was not linked to the
bxl
operon. The soluble recombinant BxlE protein was analyzed for its binding activity for xylooligosaccharides. The protein showed high-level affinity for xylobiose (

K
d

= 8.75 × 10
−9
M) and for xylotriose (

K
d

= 8.42 × 10
−8
M). Antibodies raised against the recombinant BxlE recognized the detergent-soluble BxlE isolated from
S. thermoviolaceus
membranes. The deduced BxlF and BxlG proteins are predicted to be integral membrane proteins. These proteins contained the conserved EAA loop (between the fourth and the fifth membrane-spanning segments) which is characteristic of membrane proteins from binding-protein-dependent ABC transporters. In addition, the
bxlR
gene located upstream of the
bxl
operon was cloned and expressed in
Escherichia coli
. The
bxlR
gene encoded a 343-residue polypeptide that is highly homologous to members of the GalR/LacI family of bacterial transcriptional regulators. The purified BxlR protein specifically bound to a 4-bp inverted sequence overlapping the −10 region of the
bxl
operon. The binding of BxlR to the site was inhibited specifically by low concentrations of xylobiose. This site was also present in the region located between
stxI
and
stxIV
and in the upstream region of
stxII
. BxlR specifically bound to the regions containing the inverted sequence. These results suggest that BxlR might act as a repressor of the genes involved not only in the uptake system of xylan degradation products but also in xylan degradation of
S. thermoviolaceus
OPC-520.
TheytkD(mutTA) Gene ofBacillus subtilisEncodes a Functional Antimutator 8-Oxo-(dGTP/GTP)ase and Is under Dual Control of Sigma A and Sigma F RNA Polymerases
Authors: Ramírez Martha I. , Castellanos-Juárez Francisco X. , Yasbin Ronald E. , Pedraza-Reyes Mario
Published: February 2004

The regulation of expression ofytkD, a gene that encodes the first functional antimutator 8-oxo-dGTPase activity ofB. subtilis, was studied here. AytkD-lacZfusion integrated into theytkDlocus of wild-typeB. subtilis168 revealed that this gene is expressed during both vegetative growth and early stages of sporulation. In agreement with this result,ytkDmRNAs were detected by both Northern blotting and reverse transcription-PCR during both developmental stages. These results suggested thatytkDis transcribed by the sequential action of RNA polymerases containing the sigma factors σAand σF, respectively. In agreement with this suggestion, the spore-associated expression was almost completely abolished in asigFgenetic background but not in aB. subtilisstrain lacking a functionalsigGgene. Primer extension analysis mapped transcriptional start sites on mRNA samples isolated from vegetative and early sporulating cells ofB. subtilis.Inspection of the sequences lying upstream of the transcription start sites revealed the existence of typical σA- and σF-type promoters. These results support the conclusion thatytkDexpression is subjected to dual regulation and suggest that the antimutator activity of YtkD is required not only during vegetative growth but also during the early sporulation stages and/or germination ofB. subtilis.WhileytkDexpression obeyed a dual pattern of temporal expression, specific stress induction of the transcription of this gene does not appear to occur, since neither oxidative damage (following either treatment with paraquat or hydrogen peroxide) nor mitomycin C treatment or σBgeneral stress inducers (sodium chloride, ethanol, or heat) affected the levels of the gene product produced.
Real-Time Monitoring of IntracellularStaphylococcus aureusReplication
Authors: Qazi S. N. A. , Harrison S. E. , Self T. , Williams P. , Hill P. J.
Published: February 2004

A high-throughput system to rapidly assess the intracellular replication ofStaphylococcus aureushas been developed utilizingS. aureustransformed with a dualgfp-luxABCDEreporter operon under the control of a growth-dependent promoter. Replication of tagged bacteria internalized into bovine mammary epithelial cells (MAC-T) could be measured by monitoring fluorescence and bioluminescence from the reporter operon following removal of extracellular bacteria from the plates. Bacterial replication inside cells was confirmed by a novel ex vivo time-lapse confocal microscopic method. This assay of bacterial replication was used to evaluate the efficacy of antibiotics which are commonly used to treat staphylococcal infections. Not all antibiotics tested were able to prevent intracellular replication ofS. aureusand some were ineffective at preventing replication of intracellular bacteria at concentrations above the MIC determined for bacteria in broth culture. Comparison of the fluorescence and bioluminescence signals from the bacteria enabled effects on protein synthesis and metabolism to be discriminated and gave information on the entry of compounds into the eukaryotic cell, even if bacterial replication was not prevented. Elevated resistance ofS. aureusto antibiotics inside host cells increases the likelihood of selectingS. aureusstrains which are resistant to commonly used antimicrobial agents within the intracellular niche. The approach presented directly assesses intracellular efficacy of antibiotics and provides an evidence-based approach to antibiotic selection for prescribing physicians and medical microbiologists.
α-Helix E of Spo0A Is Required for σ
A
- but Not for σ
H
-Dependent Promoter Activation in
Bacillus subtilis
Authors: Kumar Amrita , Brannigan James A. , Moran Charles P.
Published: February 2004

At the onset of endospore formation in
Bacillus subtilis
, the DNA binding protein Spo0A activates transcription from two types of promoters. The first type includes the
spoIIG
and
spoIIE
promoters, which are used by σ
A
-RNA polymerase, whereas the second type includes the
spoIIA
promoter, which is used by RNA polymerase containing the secondary sigma factor σ
H
. Previous genetic analyses have identified specific amino acids in α-helix E of Spo0A that are important for activation of Spo0A-dependent, σ
A
-dependent promoters. However, these amino acids are not required for activation of the σ
H
-dependent
spoIIA
promoter. We now report the effects of additional single-amino-acid substitutions and the effects of deletions in α-helix E. The effects of alanine substitutions revealed one new position (239) in Spo0A that appears to be specifically required for activation of the σ
A
-dependent promoters. Based on the effects of a deletion mutation, we suggest that α-helix E in Spo0A is not directly involved in interaction with σ
H
-RNA polymerase.
clpB, a Novel Member of theListeria monocytogenesCtsR Regulon, Is Involved in Virulence but Not in General Stress Tolerance
Authors: Chastanet Arnaud , Derre Isabelle , Nair Shamila , Msadek Tarek
Published: February 2004

Clp-HSP100 ATPases are a widespread family of ubiquitous proteins that occur in both prokaryotes and eukaryotes and play important roles in the folding of newly synthesized proteins and refolding of aggregated proteins. They have also been shown to participate in the virulence of several pathogens, includingListeria monocytogenes. Here, we describe a member of the Clp-HSP100 family ofL. monocytogenesthat harbors all the characteristics of the ClpB subclass, which is absent in the closely related gram-positive model organism,Bacillus subtilis.Transcriptional analysis ofclpBrevealed a heat shock-inducible σA-type promoter. Potential binding sites for the CtsR regulator of stress response were identified in the promoter region. In vivo and in vitro approaches were used to show that expression ofclpBis repressed by CtsR, a finding indicating thatclpBis a novel member of theL. monocytogenesCtsR regulon. We showed that ClpB is involved in the pathogenicity ofL. monocytogenessince the ΔclpBmutant is significantly affected by virulence in a murine model of infection; we also demonstrate that this effect is apparently not due to a defect in general stress resistance. Indeed, ClpB is not involved in tolerance to heat, salt, detergent, puromycin, or cold stress, even though its synthesis is inducible by heat shock. However, ClpB was shown to play a role in induced thermotolerance, allowing increased resistance ofL. monocytogenesto lethal temperatures. This work gives the first example of aclpBgene directly controlled by CtsR and describes the first role for a ClpB protein in induced thermotolerance and virulence in a gram-positive organism.
Biosynthesized matrix provides a key role for survival signaling in bronchial epithelial cells
Authors: Wadsworth Sam J. , Freyer Anette M. , Corteling Randolph L. , Hall Ian P.
Published: February 2004

The extracellular matrix (ECM) influences a variety of cellular functions, including survival, adhesion molecule expression, differentiation, and migration. The ECM composition of the epithelial basement membrane is altered in asthmatics. In this study, we elucidate the major survival signals received by bronchial epithelial cells in vitro by studying the effects of a variety of ECM factors and soluble growth factors on bronchial epithelial cell survival. Our findings indicate that the insulin family of soluble growth factors provides important survival signals but also that adhesion to ECM is a crucial determinant of bronchial epithelial cell survival. In the BEAS-2B bronchial epithelial cell line, collagens I and IV, laminin, fibronectin, and vitronectin provide significant levels of protection from apoptosis. Tenascin-C has no effect, whereas elastin and collagen V increase apoptosis to above control levels. BEAS-2B cells secrete their own biosynthesized matrix (BSM), which also provides rescue from apoptosis. Protection by collagen I, fibronectin, and vitronectin was found to be via an RGD domain. Laminin-, collagen IV-, and BSM-mediated survival is not RGD dependent. Primary bronchial epithelial cells exhibit a similar pattern of apoptosis rescue to the BEAS-2B cell line, although we did not observe any vitronectin-mediated protection in the primary cells. These data indicate that bronchial epithelial cell survival is dependent both on soluble growth factors and on a variety of ECM-derived signals.
FGF signaling is required for pulmonary homeostasis following hyperoxia
Authors: Hokuto Isamu , Perl Anne-Karina T. , Whitsett Jeffrey A.
Published: February 2004

To assess the role of fibroblast growth factor (FGF) signaling in pulmonary function in the postnatal period, we generated transgenic mice in which a soluble FGF receptor (FGFR-HFc) was conditionally expressed in respiratory epithelial cells of the mouse lung, thereby inhibiting FGF activity. Although FGFR-HFc did not alter postnatal lung morphogenesis, male FGFR-HFc transgenic mice were more susceptible to hyperoxia and failed to recover when ambient oxygen concentrations were normalized. Inflammation, alveolar-capillary leak, and mortality were increased following exposure to 95% FiO2. Expression of surfactant protein (SP)-A and SP-B were significantly decreased in association with decreased immunostaining for thyroid transcription factor-1. FGF signaling is required for maintenance of surfactant homeostasis and lung function during hyperoxia in vivo, mediated, at least in part, by its role in the maintenance of SP-B expression.
NaCl transport across the opercular epithelium ofFundulus heteroclitusis inhibited by an endothelin to NO, superoxide, and prostanoid signaling axis
Authors: Evans David H. , Rose Rachel E. , Roeser Jennifer M. , Stidham James D.
Published: February 2004

Recent evidence suggests that paracrine signaling agents, such as endothelin (ET), nitric oxide (NO), superoxide (O2-), and prostanoids can modulate mammalian renal function by affecting both hemodynamic and epithelial ionic transport pathways. Since these signaling pathways have been described in fish blood vessels, we hypothesized that they may control salt transport across the gill epithelium—the primary site of ion excretion in marine teleost fishes. We found that ET, the NO donors sodium nitroprusside and spermine NONOate, and the prostanoid PGE2each can produce a concentration-dependent reduction in the short circuit current ( Isc) across the isolated opercular epithelium of the killifish ( Fundulus heteroclitus), the generally accepted model for the marine teleost gill epithelium. Sarafotoxin S6c was equipotent to ET-1, suggesting that ETBreceptors are involved. Incubation with NG-nitro-l-arginine methyl ester (l-NAME) or indomethacin reduced the effect of subsequent addition of SRXS6c by 17 and 89%, respectively, suggesting the presence of an ET to NO and PGE axis. The effects of l-NAME and indomethacin were not additive, but the superoxide dismutase mimetic 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPOL) reduced the effect of SRXS6c by 34% and preincubation with l-NAME, indomethacin, and TEMPOL reduced the SRXS6c response to zero. This suggests a direct role for O2-in this axis. COX-2 appears to be the major enzyme involved in this axis because the specific COX-2 inhibitor NS-398 was twice as effective as the COX-1 inhibitor SC560 in inhibiting the SRXS6c effect. The Iscwas stimulated by the EP2agonist butaprost and inhibited by the EP1,3agonist sulprostone, suggesting both stimulatory and inhibitory PGE receptors in this tissue. Carbaprostacyclin (PGI2analog), thromboxane A2, PGF2α, and PGD2did not affect the Isc. Our data are the first to suggest the importance of an ET-stimulated and NO-, O2--, and PGE2-mediated signaling axis that can modify active extrusion of NaCl across the killifish opercular epithelium and, by inference, the marine teleost gill epithelium.
Humid heat acclimation does not elicit a preferential sweat redistribution toward the limbs
Authors: Patterson Mark J. , Stocks Jodie M. , Taylor Nigel A. S.
Published: February 2004

We tested the hypothesis that local sweat rates would not display a systematic postadaptation redistribution toward the limbs after humid heat acclimation. Eleven nonadapted males were acclimated over 3 wk (16 exposures), cycling 90 min/day, 6 days/wk (40°C, 60% relative humidity), using the controlled-hyperthermia acclimation technique, in which work rate was modified to achieve and maintain a target core temperature (38.5°C). Local sudomotor adaptation (forehead, chest, scapula, forearm, thigh) and onset thresholds were studied during constant work intensity heat stress tests (39.8°C, 59.2% relative humidity) conducted on days 1, 8, and 22 of acclimation. The mean body temperature (T̄b) at which sweating commenced (threshold) was reduced on days 8 and 22 ( P < 0.05), and these displacements paralleled the resting thermoneutral T̄b shift, such that the T̄b change to elicit sweating remained constant from days 1 to 22. Whole body sweat rate increased significantly from 0.87 ± 0.06 l/h on day 1 to 1.09 ± 0.08 and 1.16 ± 0.11 l/h on days 8 and 22, respectively. However, not all skin regions exhibited equivalent relative sweat rate elevations from day 1 to day 22. The relative increase in forearm sweat rate (117 ± 31%) exceeded that at the forehead (47 ± 18%; P < 0.05) and thigh (42 ± 16%; P < 0.05), while the chest sweat rate elevation (106 ± 29%) also exceeded the thigh ( P < 0.05). Two unique postacclimation observations arose from this project. First, reduced sweat thresholds appeared to be primarily related to a lower resting T̄b, and more dependent on T̄b change. Second, our data did not support the hypothesis of a generalized and preferential trunk-to-limb sweat redistribution after heat acclimation.
Ablation of renin-expressing juxtaglomerular cells results in a distinct kidney phenotype
Authors: Pentz Ellen Steward , Moyano Maria Alejandra , Thornhill Barbara A. , Sequeira Lopez Maria Luisa S. , Gomez R. Ariel
Published: February 2004

Renin-expressing cells are peculiar in that they act as differentiated cells, producing the hormone renin, while they also seem to act as progenitors for other renal cell types. As such, they may have functions independent of their ability to generate renin/angiotensin. To test this hypothesis, we ablated renin-expressing cells during development by placing diphtheria toxin A chain (DTA) under control of the Ren1dmouse renin promoter by homologous recombination in a two-renin gene strain ( Ren2 and Ren1d). Renin-expressing cells are essentially absent from kidneys in homozygotes ( DTA/ DTA) which, unlike wild-type mice, are unable to recruit renin-expressing cells when homeostasis is threatened. In contrast, renin staining in the submandibular gland (SMG), which expresses mainly Ren2, is normal. Homozygous mice survive normally, but the kidneys are small and have morphological abnormalities: 25% of the glomeruli are hyperplastic or atrophic, tubules are dilated and atrophic, and areas of undifferentiated cells exist near the atrophic glomeruli and tubules. However, in contrast to the very abnormal renal vessels found when renin-angiotensin system genes are deleted, the kidney vessels in homozygotes have normal wall thickness and no decrease in lumen size. Homozygotes have severely reduced kidney and plasma renin concentrations and females have reduced blood pressure. Homozygotes have elevated blood urea nitrogen and potassium levels, which are suggestive of altered renal function. We conclude that renin cells per se are necessary for the morphological integrity of the kidney and may have a role in maintenance of normal kidney function.
Delineation of responsive AVP-containing neurons to running stress in the hypothalamus
Authors: Saito Tsuyoshi , Soya Hideaki
Published: February 2004

Running becomes a stress, termed running stress, if it persists above the lactate threshold (LT) and results in enhanced plasma ACTH level in humans. Although the exact underlying regulation mechanism is still uncertain, hypothalamic AVP has been shown to play a dominant role in running-induced ACTH release. It is still not known, however, whether running stress activates the hypothalamic AVP-containing neurons that are involved in the activation of the ACTH response. For this reason, we applied our rat running stress model, in which both plasma ACTH and osmolality levels increase just above LT running (supra-LT running), to delineate which hypothalamic AVP neurons were responsive to running stress. Rats were previously habituated to running and then subjected to a 30-min run either just below or above the LT. Plasma samples were collected from these animals to determine ACTH and osmolality levels. Brains were prepared for immunocytochemistry for both AVP/Fos in the hypothalamus and enzyme immunoassay for the stalk median eminence (SME) AVP content. Only supra-LT running resulted in an increase in the number of Fos/AVP-immunoreactive neurons in both the parvocellular paraventricular nucleus (pPVN) and the magnocellular supraoptic nucleus (SON) accompanied by increased ACTH and plasma osmolality levels. Similarly, running reduced the SME content of the AVP. We thus found that AVP-containing neurons located in both the pPVN and SON are responsive to running stress just above the LT.
Effect of high-NaCl or high-KCl diet on hepatic Na+- and K+-receptor sensitivity and NKCC1 expression in rats
Authors: Tsuchiya You , Nakashima Shigeru , Banno Yoshiko , Suzuki Yuichi , Morita Hironobu
Published: February 2004

We previously reported that the bumetanide-sensitive Na+-K+-2Cl-cotransporter (NKCC1) is involved in the hepatic Na+and K+sensor mechanism. In the present study, we examined the effects of a high-NaCl or high-KCl diet on hepatic Na+and K+receptor sensitivity and NKCC1 expression in the liver of Sprague-Dawley rats. RT-PCR and Western blots were used to measure NKCC1 mRNA and protein expression, respectively. Infusion of hypertonic NaCl or isotonic KCl + NaCl solutions into the portal vein increased hepatic afferent nerve activity (HANA) in a Na+or K+dose-dependent manner. After 4 wk on a high-NaCl or high-KCl diet, HANA responses were attenuated compared with animals fed a normal diet, and NKCC1 expression was reduced. These results show that a high-NaCl or high-KCl diet decreases NKCC1 expression in the liver, and it might cause a reduction in hepatic Na+- and K+-receptor sensitivity.
Interleukin-6 and interleukin-15 are selectively regulated by lipopolysaccharide and interferon-γ in primary pig adipocytes
Authors: Ajuwon Kolapo M. , Jacobi Sheila K. , Kuske Joanne L. , Spurlock Michael E.
Published: February 2004

3T3-L1 adipocytes express the lipopolysaccharide (LPS) receptor and respond to direct stimulation with the antigen by increasing the expression of inflammatory mediators. Activation of this receptor by its ligand in the macrophage causes the activation and translocation of nuclear factor-κB (NF-κB) to the nucleus where it regulates the expression of proinflammatory cytokines and other target genes. We investigated whether LPS could stimulate NF-κB translocation in primary pig adipocytes and regulate the expression and secretion of TNF-α and IL-6. LPS clearly induced the nuclear translocation of NF-κB and also upregulated ( P < 0.05) the mRNA expression and secretion of IL-6 into the culture medium. An induction of TNF-α expression by LPS was not detected, but with extended incubation (8 h), there was a modest increase ( P < 0.09) in the media concentration of this cytokine. Inhibition of either ERK1/2, PKC, or the inhibitory G protein (Gi) with U-0126, bisindolylmaleimide HCl, and pertussis toxin, respectively, blocked ( P < 0.05) the increase in IL-6 expression caused by LPS. Because LPS administration in vivo increases circulating concentrations of IFN-γ, and because this cytokine also regulates multiple immune modulators in the adipocyte, we also determined whether IFN-γ regulates cytokine expression in primary adipocytes. Although the expression of IL-6 and TNF-α was unresponsive to IFN-γ, the expression of IL-15 was markedly upregulated ( P < 0.01). Furthermore, the induction of IL-15 expression by IFN-γ was blocked by inhibition of PKC. These data indicate that NF-κB is responsive to LPS in the adipocyte and also identify key mediators of LPS-induced IL-6 expression. In addition, we provide novel evidence that IFN-γ targets the adipocyte to induce IL-15 expression, thus indicating a possible role for the adipocyte in the regulation of T-cell function and muscle metabolism during the innate immune response.
Initiation of Spontaneous Epileptiform Events in the Rat Neocortex In Vivo
Authors: Ma Hong-tao , Wu Cai-hong , Wu Jian-young
Published: February 2004

We used voltage-sensitive dye imaging to visualize the distribution of initiation sites of the spontaneous interictal-like spikes (sISs) in rat neocortex, in vivo, induced by bicuculline or picrotoxin over the exposed cortex. The initiation site was small (approximately 200 μm diam). On average each initiation site initiated 2.0 ± 0.8 sISs (9 animals, 499 sISs, 251 sites). This is significantly different from that in neocortical slices, where each initiation site initiated 30–100 sISs. The initiation sites were not randomly distributed. The distance between two consecutive sites tended to be either <800 or >1200 μm, suggesting a temporal “suppression annulus” surrounding each initiation site. Within the annulus, the likelihood for initiating the next sIS was reduced. Suppression annulus did not have a noticeable change in the presence of GABAb antagonist, suggesting it did not depend on the GABAb inhibition. We also applied bicuculline locally to a spot of 800 × 800 μm2 for approximately 45 min. During this period approximately 1000 sISs occurred within the spot. Bicuculline or picrotoxin was then applied to the entire craniotomy window. The pretreatment created an obvious cluster of initiation sites. Around this cluster, the suppression annulus became obvious in individual animals. Our results suggest that, in disinhibited cortex, epileptiform events were initiated from small sites. The initiation sites may cluster in an area with increased local activity. Surrounding each initiation site there may be a temporal suppression annulus.
Involvement of the Ryanodine Receptor in Morphologic Modification ofHermissendaType B Photoreceptors After In Vitro Conditioning
Authors: Kawai Ryo , Horikoshi Tetsuro , Sakakibara Manabu
Published: February 2004

We examined whether Ca2+induced Ca2+release through ryanodine receptors is involved in the conditioning of specific morphologic changes at the axon terminals of type B photoreceptors in the isolated circumesophageal ganglion of Hermissenda. Calcium chelation by bis(2-aminophenoxy) ethane- N,N,N′, N′-tetraacetic acid prevented the conformational change at the terminals after five paired presentations of light and vibration, which produce terminal branch contraction of B photoreceptors. Two ryanodine receptor blockers, dantrolene and micromolar concentrations of ryanodine, depressed the increase in excitability due to in vitro conditioning and the increase in intracellular Ca2+in response to membrane depolarization. Although the ability to increase intracellular Ca2+was depressed, synaptic transmission was preserved in the normal state from hair cells under dantrolene and ryanodine incubation. Ryanodine receptor blockers also prevented contraction at the B photoreceptor axon terminals. These results suggest that the ryanodine receptor has a crucial role in inducing the in vitro conditioning specific changes both physiologically and morphologically, including “focusing” at the B photoreceptor axon terminal.
Riluzole-Sensitive Slowly Inactivating Sodium Current in Rat Suprachiasmatic Nucleus Neurons
Authors: Kononenko Nikolai I. , Shao Li-Rong , Dudek F. Edward
Published: February 2004

The persistent (i.e., slowly inactivating) fraction of the Na current ( INa,P) regulates excitability of CNS neurons. In isolated rat suprachiasmatic nucleus (SCN) neurons with a ramp-type voltage-clamp protocol, we have studied the properties of a robust current that has the general properties of INa,P but exhibits a slow inactivation ( INa,S). The time dependence of the development of the inactivation was also studied by clamping of the membrane potential at different levels: time constants ranging from ∼50 to ∼700 ms, depending on the voltage level, were revealed. The INa,S (50–150 pA) was present in both spontaneously active and silent neurons. The neurons exhibited INa,S without visible rundown during ∼1-h recordings. INa,S had a threshold between –65 and –60 mV and was maximal at about –45 mV. Tetrodotoxin (TTX; 1 μM) completely and reversibly blocked INa,S. Riluzole, an effective blocker of INa,P, inhibited reversibly INa,S with an EC50 of 1–2 μM. Microapplication of 10 μM riluzole during either extracellular or intracellular recording suppressed spontaneous activity in isolated SCN neurons. In the slice preparation, bath application of 20 μM riluzole resulted in decreased firing rate or complete suppression of spontaneous activity in some neurons (9/14) but had no effect on other neurons (5/14). In riluzole-resistant neurons in cell-attached experiments, low-amplitude current spikes were present in 1 μM TTX. We concluded that INa,S is ubiquitously expressed by all SCN neurons and that this current is a necessary but not sufficient depolarizing component of the mechanism for spontaneous firing.
Differences in Glycinergic mIPSCs in the Auditory Brain Stem of Normal and Congenitally Deaf Neonatal Mice
Authors: Leao Richardson N. , Oleskevich Sharon , Sun Hong , Bautista Melissa , Fyffe Robert E.W. , Walmsley Bruce
Published: February 2004

We have investigated the fundamental properties of central auditory glycinergic synapses in early postnatal development in normal and congenitally deaf ( dn/dn) mice. Glycinergic miniature inhibitory postsynaptic currents (mIPSCs) were recorded using patch-clamp methods in neurons from a brain slice preparation of the medial nucleus of the trapezoid body (MNTB), at 12-14 days postnatal age. Our results show a number of significant differences between normal and deaf mice. The frequency of mIPSCs is greater (50%) in deaf versus normal mice. Mean mIPSC amplitude is smaller in deaf mice than in normal mice (mean mIPSC amplitude: deaf, 64 pA; normal, 106 pA). Peak-scaled fluctuation analysis of mIPSCs showed that mean single channel conductance is greater in the deaf mice (deaf, 64 pS; normal, 45 pS). The mean decay time course of mIPSCs is slower in MNTB neurons from deaf mice (mean half-width: deaf, 2.9 ms; normal, 2.3 ms). Light- and electron-microscopic immunolabeling results showed that MNTB neurons from deaf mice have more (30%) inhibitory synaptic sites (postsynaptic gephyrin clusters) than MNTB neurons in normal mice. Our results demonstrate substantial differences in glycinergic transmission in normal and congenitally deaf mice, supporting a role for activity during development in regulating both synaptic structure (connectivity) and the fundamental (quantal) properties of mIPSCs at central glycinergic synapses.
Synaptic Dynamics on Different Time Scales in a Parallel Fiber Feedback Pathway of the Weakly Electric Fish
Authors: Lewis John E. , Maler Leonard
Published: February 2004

Synaptic dynamics comprise a variety of interacting processes acting on a wide range of time scales. This enables a synapse to perform a large array of computations, from temporal and spatial filtering to associative learning. In this study, we describe how changing synaptic gain via long-term plasticity can act to shape the temporal filtering of a synapse through modulation of short-term plasticity. In the weakly electric fish, parallel fibers from cerebellar granule cells provide massive feedback inputs to the pyramidal neurons of the electrosensory lateral line lobe. We demonstrate a long-term synaptic enhancement (LTE) of these synapses that is biochemically similar to the presynaptic long-term potentiation expressed by parallel fibers in the mammalian cerebellum. Using a novel stimulation protocol and a simple modeling paradigm, we then quantify the changes in short-term plasticity during the induction of LTE and show that these changes can be explained by gradual changes in only one model parameter, that which is associated with the baseline probability of transmitter release. These changes lead to a shift in the spike frequency preference of the synapse, suggesting that long-term plasticity is not only involved in controlling the gain of the parallel fiber synapse, but also provides a means of controlling synaptic filtering over multiple time scales.
Jacobian Conditioning Analysis for Model Validation
Authors: Rivals Isabelle , Personnaz Léon
Published: February 2004

Our aim is to stress the importance of Jacobian matrix conditioning for model validation. We also comment on Monari and Dreyfus (2002), where, following Rivals and Personnaz (2000), it is proposed to discard neural candidates that are likely to overfit and/or for which quantities of interest such as confidence intervals cannot be computed accurately. In Rivals and Personnaz (2000), we argued that such models are to be discarded on the basis of the condition number of their Jacobian matrix. But Monari and Dreyfus (2002) suggest making the decision on the basis of the computed values of the leverages, the diagonal elements of the projection matrix on the range of the Jacobian, or “hat” matrix: they propose to discard a model if computed leverages are outside some theoretical bounds, pretending that it is the symptom of the Jacobian rank deficiency.

We question this proposition because, theoretically, the hat matrix is defined whatever the rank of the Jacobian and because, in practice, the computed leverages of very ill-conditioned networks may respect their theoretical bounds while confidence intervals cannot be estimated accurately enough, two facts that have escaped Monari and Dreyfus's attention. We also recall the most accurate way to estimate the leverages and the properties of these estimations. Finally, we make an additional comment concerning the performance estimation in Monari and Dreyfus (2002).
Reply to the Comments on “Local Overfitting Control via Leverages” in “Jacobian Conditioning Analysis for Model Validation” by I. Rivals and L. Personnaz
Authors: Oussar Yacine , Monari Gaétan , Dreyfus Gérard
Published: February 2004

“Jacobian Conditioning Analysis for Model Validation” by Rivals and Personnaz in this issue is a comment on Monari and Dreyfus (2002). In this reply, we disprove their claims. We point to flawed reasoning in the theoretical comments and to errors and inconsistencies in the numerical examples. Our replies are substantiated by seven counterexamples, inspired by actual data, which show that the comments on the accuracy of the computation of the leverages are unsupported and that following the approach they advocate leads to discarding valid models or validating overfitted models.