bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal human serum antibody responses to outer membrane antigens of Actinobacillus actinomycetemcomitans
Authors: Ebersole Jeffrey L. , Steffen Michelle J. , Cappelli David
Published: October 2003

Abstract. We hypothesize that serum antibody responses to antigens of a periodontopathogen would vary temporally and that the specificity of these host antibodies would relate to infection and disease activity. To test the hypothesis, we obtained between 6 and 13 serum samples from Actinobacillus actinomycetemcomitans (Aa)‐positive (serological and microbiological) periodontitis patients at time points between 18 and 42 months into the study, and evaluated specific antibody responses to outer membrane antigens (OMA) of Aa strain Y4. Sera from these patients detected 22 different OMA. Early‐onset (EOP; n=7) and adult (AP; n=11) periodontitis patients responded to 35% and 41% of the OMA, respectively. 2 of 9 sera from healthy subjects detected no antigens and 7/9 sera detected 77% of the OMA (p<0.0001 versus EOP and AP). The frequency of antibody responses to the 17 kDa antigen were similar between diseased, infected patients and the uninfected, normal subjects, suggesting that it may be stimulated as a cross‐reactive antigen. Antibody to the 28, 38, and 90 kDa antigens were significantly more common in diseased patients (±90%) versus normal subjects (p<0.01, p<0.002, and p<0.002, respectively) and were unique among diseased, infected patients, which may be indicative of infections with Aa. A 65 kDa antigen showed an increased frequency of reaction in the AP versus the EOP (p= 0.01) patients, which exemplified a potential distinction in response to Aa between adult and early‐onset disease classifications. Seventeen of 22 OMA could be detected in every sample from at least one patient. Longitudinal samples from seropositive EOP and AP reacted 80–100% of the time with the 17, 28, and 100 kDa antigens. Finally, five antigens of 15, 38, 58, 65, and 79 kDa were detected in 33–83% of the seropositive patients; however, antibody to these OMA reacted variably at different sampling points, suggesting some antigenic response diversity over time.
During Pregnancy, in the Context of a Th2‐Type Cytokine Profile, Serum IL‐6 Levels Might Condition the Quality of the Synthesized Antibodies
Authors: MARGNI RICARDO A. , ZENCLUSSEN ANA CLAUDIA
Published: October 2003

PROBLEM: In recent years, the central role of cytokines in the immune response has been widely studied. It is considered that a T helper (Th)1‐type cytokine profile is associated with the rejection phenomenon, whereas a Th2‐type cytokine profile is associated with immunological tolerance. In pregnancy, the enhanced Th2/Th1 ratio seems to be necessary to fetal protection. Taking into account that a Th2‐type response means antibody production by B cells, and that these antibodies could induce degradation of the paternal antigens, we investigated the quality of the antibodies produced during pregnancy and their regulation.  METHOD OF STUDY: Review of previous data.  RESULTS: The regulation of protective antibodies by IL‐6 in a dose‐dependent fashion is proposed as a hypothesis.  CONCLUSION: Cytokines play a central role in the success (or failure) of pregnancy. However, the quality of the synthesized antibodies is also a regulatory key. The preferential synthesis of asymmetric immunoglobulin G antibodies during pregnancy could be one of the several pathways that lead to a successful pregnancy
Enhancement of In Vitro hsp72 Expression by Placental IL‐6
Authors: MIRANDA S. , GENTILE T. , MARGNI R.
Published: October 2003

PROBLEM: To give an approach in order to elucidate the mechanism by which placental IL‐6 induce modifications in the glycosylation status of immunoglobulins, in the present work, we investigate a putative relationship between a stimulus by placental IL‐6 and expression of cytoplasmic “hsp70 family proteins” in an in vitro model. 
METHODS OF STUDY: Supernatants of cultures of placentae obtained from primiparous and multiparous AKR/J×AKR/J and AKR/J×BALB/c mouse crossbreedings were added to mouse IgG1 hybridoma cultures which produced symmetric and asymmetric anti‐dinitrophenol (anti‐DNP) antibodies. Analyses of the expression of inducible hsp72/constitutive hsp73 in cellular lysates obtained from hybridomas cultured, in the presence of rmIL‐6 or crude murine placental culture supernatants, followed by neutralization assays with anti IL‐6, were performed. In addition, the level of IL‐6 present in the employed placental culture supernatants was determined and compared with the placental hsp70‐inducing effect. 
RESULTS: These experiments showed that mouse placentae were able to release IL‐6 in vitro. In addition, mouse placental supernatants (PS) containing over 1,000 pg/mL of IL‐6 enhanced the expression of the inducible isoform hsp72 in the employed hybridomas. This effect was abolished when the hsp70‐inducing PS were previously incubated with anti‐mIL6 antibody. 
CONCLUSIONS: These observations indicate that mouse placentae produce different titers of IL‐6 and suggest that IL‐6 appears to be the unique mouse placental factor able to induce in vitro hsp72 synthesis. A relationship with the increased synthesis of anti‐paternal antigen asymmetric antibodies, previously observed during pregnancy, is discussed.
Circulating Human Antisperm Antibodies Recognize Prostasomes
Authors: ALLEGRUCCI CINZIA , RONQUIST GUNNER , NILSSON B OVE , CARLSSON LENA , LUNDQUIST MONALILL , MINELLI ALBA , LARSSON ANDERS , RONQUIST GUNNAR , CARLSSON LENA , LARSSON ANDERS , OVE NILSSON B. , LUNDQVIST MONALILL
Published: October 2003

PROBLEM: The presence of naturally occurring antisperm antibodies (ASA) is a well‐known cause of infertility in men and women, but the antigens for these antibodies are usually poorly characterized. Prostasomes, organelles secreted by human prostatic acinar cells and expelled into the seminal plasma at ejaculation, can adhere to sperm cells. Thus, we have examined whether prostasomes could be an antigen for ASA.  METHOD OF STUDY: We have studied the reactivity of chicken antiprostasome antibodies with sperm cells in an agglutination test and conversely the reactivity of serum positive for ASA from 20 infertile patients, with spermatozoa using flow cytometry and with purified prostasomes using enzyme‐linked immunosorbent assay.  RESULTS: The chicken antiprostasome antibody caused agglutination of sperm cells similarly to the agglutination observed with patients’ sera. All of these patients’ sera contained IgG antibodies against prostasomes.  CONCLUSIONS: The high percentage of patients with antiprostasome antibodies in this study shows that prostasomes could be one of the major targets for ASA.
Study of knowledge of genital herpes infection and attitudes to testing for genital herpes among antenatal clinic attendees
Authors: Edmiston Natalie , O'Sullivan Maree , Charters Deryck , Chuah John , Pallis Lucinda
Published: October 2003

A descriptive survey of knowledge of genital herpes and attitudes to testing was conducted among antenatal clinic attendees at the Gold Coast Hospital, Australia. The study subjects showed a good knowledge of genital herpes, to a level that appears sufficient for an informed choice regarding herpes serology testing to be made. A preference for testing for genital herpes was suggested. Although serological testing is not routinely required, the results of the study indicate that discussion of genital herpes should be considered in the antenatal clinic setting.
Implanon implant detection with ultrasound and magnetic resonance imaging
Authors: Campbell Westerway Susan , Picker Richard , Christie James
Published: October 2003

Objective: The objective of the present study was to determine the degree of difficulty in locating Implanon (Organon, Sydney, Australia) contraceptive rods which had been inserted suboptimally, using both ultrasound and magnetic resonance imaging (MRI).

Methods: Volunteers with correctly placed Implanon rods were recruited for normal scanning protocols. A phantom was used to display abnormal rod placements. Ultrasound imaging was carried out using a variety of transducers to demonstrate their suitability. An MRI scanning protocol was formulated to achieve required views in the shortest time.

Results: All Implanon rods were successfully imaged with both ultrasound and MRI.

Conclusion: High resolution linear array transducers combined with the correct scanning protocol should enable visualisation of Implanon rods in almost all cases. The MRI imaging requires caution when differentiating blood vessels and fibrous septae from the Implanon rods.
Betamethasone associated changes in umbilical artery flow velocity waveforms in multiple pregnancies with umbilical artery absent end diastolic flow
Authors: Barkehall‐Thomas Andrea , Thompson Melanie , Baker Lesleigh S. , Edwards Andrew , Wallace Euan M.
Published: October 2003

Objectives: It has been previously shown that glucocorticoids alter umbilical artery flow velocity waveforms in singleton pregnancies complicated by umbilical artery absent end diastolic flow. Whether similar effects are evident in multiple pregnancies where one fetus has umbilical artery absent end diastolic flow is not known.

Methods: Women with a twin or triplet pregnancy complicated by umbilical artery absent end diastolic flow in one fetus were admitted to hospital for intensive fetal surveillance including daily umbilical artery flow velocity waveform studies, as per hospital protocol. All women received prophylactic betamethasone (11.4 mg × 2, 24 h apart) in anticipation of preterm delivery.

Results: Between October 1996 and February 2002, 24 women with a multiple pregnancy complicated by umbilical artery absent end diastolic flow were cared for. Of these, six had a pregnancy with feto‐fetal transfusion and excluded from further analysis. Of the remaining 18 women, eight had monochorionic diamniotic twins, eight had dichorionic twins, and two had trichorionic, triamniotic triplets. The median (range) gestation at diagnosis of umbilical artery absent end diastolic flow was 210.5 days (173–241). In nine (50%) of the 18 pregnancies the administration of betamethasone was associated with return of umbilical artery end diastolic flow for a median of 5 days. There was no association between this effect and chorionicity. The median (range) interval from diagnosis of umbilical artery absent end diastolic flow to delivery was 11 days (1–46).

Conclusions: As previously reported in singleton pregnancies, the maternal administration of betamethasone in multiple pregnancies with umbilical artery absent end diastolic flow is associated with a transient return of end diastolic flow.
At 3 am who the Hell do you Call? Case Management Issues in Sole Practice as a Rural Community Mental Health Nurse
Authors: Gibb Heather , Livesey Lynnda , Zyla Walter
Published: October 2003

Objective: This paper presents a section of data from a larger study into the sole practice of rural community mental health nurses, highlighting the uniqueness of the therapeutic model and the stresses associated with sole practice.

Method: A grounded theory method was used that involved interviews with senior community mental health nurses from five rural and remote sites in New South Wales.

Results: Rural mental health nurses engage community structures in a unique way, strategically as therapeutic tools supporting recovery or maintenance of an independent lifestyle. Findings also highlight the current strain that sole practice places on nurses, such as the insecurity of bearing responsibility beyond which nurses are formally authorised, in the absence of formal mentoring or professional development.

Conclusions: Suggestions for resolving these tensions include virtual teams and Nurse Practitioner roles.
Rural Workforce Development and Staff Support: Remodelling Service Provision for Early Intervention in Child and Adolescent Mental Health
Authors: Kowalenko Nick , Bartik Warren , Whitefield Kathy , Wignall Ann
Published: October 2003

Objective: Through professional workforce development, focused clinical placements and local consultation this innovative project aimed to develop and evaluate a best practice staff-support model by strengthening a rural—urban partnership.

To sustain the impact of the program, the project incorporated multilevel interventions (developing strategic partnerships and providing support to all levels of staff from management to front-line) and included multiple components (engaging media partnerships to boost community awareness, management briefings, staff education and training, consultative support and clinical placements) to reorient services, and the broader community, towards early intervention.

Methods: Structured key informant interviews were conducted with rural mental health staff to evaluate outcomes of the clinical placements and consultation sessions. Evaluations of the education and training courses were also conducted.

Results: At project commencement, 43% of the rural child and adolescent mental health staff reported good skills in the identification and treatment of depression and anxiety. Following the project, 86% of staff reported good to very good skills in these areas. Rural professionals reported greater work satisfaction and an increase in their skills and confidence. They also reported that their involvement had further enhanced their work practices in child and adolescent mental health.

Conclusions: This collaborative project is an example of a best practice model for staff-support. It has developed workforce capacity to provide a range of early intervention initiatives and provided the consultative skills to initiate their implementation.

Above all, the approach taken by the project is feasible. It is a replicable model that supports the orientation of rural mental health services towards early intervention.
Bridging the Information Gap: IT and Health in Indigenous Populations
Authors: Hunter Ernest , Travers Helen , McCulloch Brad
Published: October 2003

Objective: A proof of concept evaluation of the use of touch-screen technology to address specific health issues in Indigenous settings and exploration of potential relevance to Indigenous mental health.

Methods: Quantitative and qualitative approaches were utilised to evaluate two touchscreen units with sound located in Indigenous settings (one clinical and the other a Centrelink office) with content on two topics-diabetes and musculoskeletal problems. Quantitative information included trace analysis and on-screen questionnaires. Qualitative information included individual and group interviews, and observation over a period of 10 months.

Results: Use was consistent over time. Subject areas were equally accessed with most users entering only one area per session. Mean session time was five minutes and clinical setting users were more likely to answer on-screen questions. The majority considered use ‘easy’ with the proportion indicating use‘very hard’ increasing with age. Across both sites, women's health, children and drugs and alcohol were identified as issues for which more information was needed. Interview data emphasised the importance of Indigenous and recognisable voices with non-text based content relevant to the local context.

Conclusion: Touch-screen technology offers a means to provide relevant and accessible health information in Indigenous settings and may contribute to overcoming the‘information gap’. There are obvious implications in relation to Indigenous mental health.
Action Research Intervention with Young People: A City Council's Response
Authors: Selby Jane , Bradley Benjamin
Published: October 2003

Objective: Interventions with young people at risk use a range of programmes. We describe how a group of young people came to perform their stories publicly. In this paper, we consider their local City Council and a change in its thinking.

Methods: The project is built upon ideas of community development that incorporate techniques such as Public Conversations and a commitment to prioritising the voices of the young people under scrutiny. The project as a whole is based on action research. We helped to establish a youth-led group of 10 people (13–22 years) to work with three experienced theatre personnel. In documenting the sessions through videotaping and interviewing individuals including councillors, we were able to document some consequences of the intervention on the young people and on their community.

Results: In evaluating the impact of the processes put in place, we trace changes from resistance to the employment of a youth coordinator to financing such a position by the local council.

Conclusions: We consider issues about evaluating interventions so as to emphasise the need for reflecting on innovative ways of documenting associated social change.
Child and Adolescent Telepsychiatry in New South Wales: Moving Beyond Clinical Consultation
Authors: Starling Jean , Rosina Robyn , Nunn Kenneth , Dossetor David
Published: October 2003

Objectives: Telepsychiatry has been demonstrated to be an effective and acceptable way to deliver psychiatry services to remote and rural areas. This paper describes the initial evaluation of the Child and Adolescent Psychological Telemedicine Outreach Service (CAPTOS) in New South Wales and the changes made to the service after the initial evaluation.

Methods: The evaluation investigated patients’, rural clinicians’ and CAPTOS psychiatrists’ satisfaction with the quality of the service and the technology.

Results: There were 136 rural families, 20 rural clinicians and eight psychiatrists. Overall, satisfaction was high with the rural families and clinicians being the most satisfied (95–99% very or mostly satisfied). CAPTOS psychiatrists felt that they were usually able to perform an adequate consultation (87%) but few (16%) felt the consultations were as satisfactory as a face to face consultation. Because of the initial evaluation, and the ongoing collaboration with rural clinicians, further services were developed using the technology and the developing professional networks. These initiatives included telenursing, professional skills development, sabbaticals for rural clinicians and a clinical skills workshop for rural clinicians.

Conclusions: This study confirms telepsychiatry as a useful service for remote and rural children and families. The results also suggest some reasons why urban clinicians show the least enthusiasm for the service. Ways of addressing some of the limitations of the service are suggested, and the expansion of CAPTOS to meet the needs of rural clinicians is discussed.
Changing the Environment of Schizophrenia at the Community Level
Authors: Warner Richard , Mandiberg James
Published: October 2003

Objectives: One may categorise environmental factors as operating at the individual, domestic or community level. This paper reviews important factors influencing schizophrenia at the community level: the availability of work, economic disincentives to work and stigma and discrimination.

Conclusions: Work helps decrease the alienation of people with schizophrenia and aids recovery. In much of the developed world, however, few people with serious mental illness are employed. To improve the employment of people with schizophrenia, we could (a) create small enterprises to provide opportunities for people with schizophrenia to work in a mixed workforce; and (b) look within the mental health service budget for possible contracts for consumer-employing business.

People with schizophrenia are subject to prejudice, discrimination and stigma. Modern communication technology, however, can be harnessed to fight stigma and prejudice. At the local level, we can lobby the entertainment and news media and develop targeted campaigns. Some successful antistigma campaigns are described.
What Developed Countries can Learn from Developing Countries in Challenging Psychiatric Stigma
Authors: Rosen Alan
Published: October 2003

Objective: This paper will raise the following issues for debate:Is the nature of and threshold for psychiatric stigma different between developed and developing countries?Are we able to generalise comparisons about psychiatric stigma between countries, or does it differ essentially from culture to culture?Does mental health illiteracy or general illiteracy favour more stigma or less stigma?What can developed countries learn from developing countries in generating effective methods of challenging psychiatric stigma?

Conclusion: Most approaches to challenging stigma associated with severe psychiatric illness and disability have been generated in developed countries without reference to lessons from developing countries, and then export, largely without modification, is often attempted to these developing countries. The Program for Psychosocial Recovery and Development in East Timor team has exemplified how sensitively delivered psychiatric interventions can be welcomed by a community long deprived of adequate services. These studies also have practical relevance to Aboriginal, Torres Strait Islander and Maori communities where individuals with mental illness frequently experience ‘double-whammy’ stigmatisation and discrimination.
Contradictory Australian National Policies on Self-Harm And Suicide: The Case of Asylum Seekers in Mandatory Detention
Authors: Dudley Michael
Published: October 2003

Objective: This paper argues that the decision by the Australian Commonwealth Government to continue its policy of indefinite mandatory detention, without review, in the face of the accumulated evidence regarding the harmful effects, amounts to state-sponsored trauma and child neglect and/or abuse.

Conclusions: The Australian government's policies supporting successful suicide prevention programs stand in contrast to its policy regarding indefinite mandatory detention of onshore asylumseekers. Men's and women's rates of suicidal behaviours in Australian immigration detention centres (IDCs), while imprecise, are calculated as 41 and 26 times the national average, respectively, and male IDC rates are 1.8 times the male prison rates. Self-harm in detention reflects a convergence of (child) health, protection and human rights concerns, and is driven by the extremity of detention and the detention environment. Recommendations are made for these concerns to be immediately addressed. It is noted that in handling this unprecedented situation, the government has not sought advice from its own advisory councils.
Atrial plasma ANP and NH2‐terminal proANP during right atrial pressure increase in humans
Authors: ARJAMAA O. , KARLQVIST K. , VAINIONPÄÄ V. , LEPPÄLUOTO J. , VUOLTEENAHO O.
Published: October 2003

To compare plasma NT‐proANP, a stable and biologically inactive N‐terminal portion of ANP prohormone, with the known plasma ANP response to increased right atrial pressure a Swan–Ganz catheter was inserted into the right atrium of five normal healthy male volunteers. The elevation of right atrial pressure was produced by a head‐down tilt after a hypertonic saline infusion. Blood samples were drawn from the lumen of the right atrium. After 5 min of starting the tilt the right atrial pressure had increased from 7.0±1.0 to 11.6±0.9 mmHg (P<0.05) and then began to normalize in spite of the constant tilt. Atrial plasma ANP increased in relation to the pressure increase and peaked at 15 min after the start of the tilt. The change was from 27.9±6.5 to 53.9±9.7 pmol L‐1 (P<0.05). Atrial plasma NT‐proANP increased significantly from 357±91.2 to 529.1±116.0 pmol L‐1 (P<0.05) at 10 min and remained high throughout the experiment. The molar ratio of NT‐proANP to ANP varied in atrial plasma from 9.5±1.2 to 13.9±2.7 showing that the plasma clearance of ANP from plasma was much higher than that of NT‐proANP.
cAMP‐induced chloride transport in NCL‐SG3 sweat gland cells
Authors: MÖRK A‐C. , VON EULER A. , ROOMANS G. M. , RING A.
Published: October 2003

cAMP‐induced ion transport in a human sweat gland cell line, NCL‐SG3, was investigated by X‐ray microanalysis and patch‐clamp technique. Stimulation with cAMP caused a decrease in the cellular Cl and K. cAMP had no significant effect on the intracellular Na and Ca. Chloride channel blockers (9‐AC, DPC and NPPB) inhibited the cAMP‐induced chloride efflux. In patch‐clamp experiments the inward current increased over a period of 5–15 min on addition of membrane‐permeable cAMP in 66% of the attempts when the cell was held at 0 mV and pulsed to negative membrane potentials. The inward current was completely blocked by chloride channel blockers. Washout reversed the effect of cAMP. The inward current was not diminished by substitution of impermeable cations for Na in the bath and was insensitive to TEA (tetraethylammoniumchloride). It is concluded that the inward current is mainly a chloride current. Cystic fibrosis transmembrane regulator (CFTR) could not be demonstrated in the NCL‐SG3 cells. It is therefore possible that the chloride efflux is mediated by other types of chloride channels.
Effect of nicotine infusion in humans on platelet aggregation and urinary excretion of a major thromboxane metabolite
Authors: NOWAK J. , ANDERSSON K. , BENTHIN G. , CHEN J. , KARLBERG K.‐E. , SYLVÉN C.
Published: October 2003

The objective of this study was to evaluate further a possible role of nicotine as a stimulator of platelet aggregability and platelet arachidonic acid metabolism in vivo. In six healthy, non‐smoking males, platelet aggregability was assessed by filtragometry and impedance aggregometry before, during and after an intravenous infusion of nicotine at two different doses (0.25 and 0.5 μg kg‐1 min‐1) for 30 min. The aggregatory response was also measured after the addition of nicotine at final concentrations ranging from 10‐11 mol L‐1 to 10‐5 mol L‐1 directly to the aggregating blood. The synthesis of thromboxane A2 (TxA2) in platelets was estimated by quantitating the urinary excretion of 2,3‐dinor‐thromboxane B2 (Tx‐M). Despite the plasma concentrations of nicotine, cotinine and catecholamines in the range of those occurring during acute cigarette exposure, the excretion of Tx‐M (204±36 pg mg‐1 creatinine) remained unaltered during nicotine infusion. Similarly, platelet aggregatory response to collagen was not influenced by nicotine when infused or added in vitro. However, an enhanced aggregability was detected by filtragometry during the infusion of nicotine at the higher dose employed. The results indicate that nicotine, infused at moderate doses, produces a weak platelet stimulation that is not accompanied by significant release of thromboxane A2, as monitored by urinary excretion of Tx‐M. Although a direct action of nicotine on platelets cannot be excluded, it appears more likely that the enhancement of platelet function is mediated by other, secondary mechanisms.
Nitric oxide synthase inhibitors enhance plasma levels of corticosterone and ACTH
Authors: GIORDANO M. , VERMEULEN M. , TREVANI A. S. , DRAN G. , ANDONEGUI G. , GEFFNER J. R.
Published: October 2003

The role of nitric oxide in the regulation of adrenal steroidogenesis was examined in BALB/c mice by employing the nitric oxide synthase inhibitors NG‐nitro L‐arginine methyl ester (L‐NAME) and NG‐nitro L‐arginine (L‐NNA). The administration of a single dose of nitric oxide inhibitors (50 mg kg‐1 body wt, i.p.) induced a fourfold increase in plasma corticosterone. Treatment with L‐arginine (750 mg kg‐1 body wt, s.c.), but not D‐arginine, completely prevented corticosterone increases induced by L‐NAME. To analyse whether the activation of adrenal steroidogenesis induced by nitric oxide synthase inhibitors involved the stimulation of the hypothalamo‐pituitary‐adrenal axis, ACTH levels were assessed. It was found that L‐NAME significantly enhanced plasma ACTH concentrations. Genetic variations in this regulatory pathway are suggested by the fact that L‐NAME increased corticosterone levels in BALB/c, C3H/He and DBA‐2 mice, but not in C57Bl/c mice, a strain characterized by a low steroid response to stress.
Substance P‐induced respiratory excitation is blunted by δ‐receptor specific opioids in the rat medulla oblongata
Authors: CHEN Z. , HEDNER J. , HEDNER T.
Published: October 2003

The effects of substance P (SP) and the naturally occurring met‐enkephalin and the synthetic μ‐specific opioid agonist, DAGO (Tyr‐d‐Ala‐Gly‐N‐Methy‐Phe‐Gly‐ol) and the δ‐specific opioid agonist DADL (Tyr‐d‐Ala‐Gly‐Phe‐d‐Leu) on basal ventilation were investigated in halothane‐anaesthetized rats. Local injections of SP (0.75–1.5 nmol) in the ventrolateral medulla oblongata (VLM), e.g. nucleus paragigantocellularis, and nucleus reticularis lateralis increased ventilation because of an elevation of tidal volume. Met‐enkephalin induced a short‐lasting ventilatory depression mainly because of a depression of tidal volume. Activation of δ‐ and μ‐opioid receptors in the VLM by local application of DADL and DAGO, respectively, induced ventilatory depression, which was later in onset and more long‐lasting. Local administration of met‐enkephalin into the VLM also produced a long‐lasting inhibition of the SP‐induced ventilatory excitation. A similar blockade of the SP‐induced excitatory ventilatory response could be elicited by DADL but not by DAGO. This antagonistic effect was attenuated by local application of the δ‐opioid receptor antagonist ICI 154.129. We conclude that the naturally occurring met‐enkephalin as well as synthetic μ‐ and δ‐specific enkephalin analogues (DAGO and DADL, respectively) in VLM depress basal ventilation by an effect on inspiratory drive. There is a functional antagonism between activation of δ‐opioid receptors and SP receptors into the VLM in respect to respiratory regulation.
Hypotonic swelling or stretch does not change cytosolic calcium in mouse renal juxtaglomerular cells
Authors: SCHOLZ H. , JURK S. , KURTZ A.
Published: October 2003

This study aimed to examine the influence of cell swelling and of direct mechanical stretch on the cytosolic calcium concentration in mouse renal juxtaglomerular cells. To this end JG cells located in isolated mouse renal afferent arterioles were exposed to hypotonic extracellular fluid to cause cell swelling or were mechanically stretched and cytosolic calcium was monitored with fura‐2 calcium microspectrofluorimetry. None of the above mentioned manoeuvres caused an increase of cytosolic calcium in the juxtaglomerular cells, which all responded to ionomycin (5 μg mL‐1) with a marked calcium mobilization. Exposure of cultured rat renal mesangial cells to hypotonic buffer or direct mechanical stress increased cytosolic calcium in 90% of the cells under investigation. These findings suggest that cell swelling or an increased stretch of the plasma membrane of juxtaglomerular cells located in renal afferent arterioles does not lead to measurable increases of the cytosolic calcium concentration. It appears less likely therefore that a membrane‐stretch regulated calcium influx has a major functional role in JG cells.
A role for islet peptide YY in the regulation of insulin secretion
Authors: KARLSSON S. , AHRÉN B.
Published: October 2003

The authors are grateful to Ms L. Bengtsson and Ms L. Kvist for technical assistance. The study was financially sup ported by The Swedish Medical Research Council (grants no. 14X‐6834 and 12X‐712); The Novo Nordic Founda tion; Swedish Diabetes Association; The Crafoord, Albert Pa~Olsson and Ernhold Lundstro~Dm Foundations and by the Faculty of Medicine, Lund University, Lund, Sweden.
Elastic properties in the circumferential direction in isolated rat small intestine
Authors: DUCH B. U. , PETERSEN J. A. K. , VINTER‐JENSEN L. , GREGERSEN H.
Published: October 2003

The aim was to study the passive biomechanical wall properties in the isolated duodenum, jejunum and ileum of the rat. The organ bath contained a Krebs–Ringer solution with 10‐2m MgCl2 to abolish smooth muscle contractile activity. Stepwise inflation of an intraluminal balloon, in which the cross‐sectional area (CSA) was measured, provided the distension stimulus. The circumferential wall stress–strain distributions were computed from steady‐state values of these measurements and the unstressed wall thickness was measured in order to evaluate the passive elastic properties. The CSAs measured increased from duodenum to jejunum and to ileum (P<0.001). At the highest applied pressure load the CSA was 16.64±0.46 mm2 for the duodenum, 18.70±0.53 mm2 for the jejunum and 21.73±0.49 mm2 for the ileum. The wall thickness was 0.19±0.01, 0.25±0.01 and 0.28±0.02 mm, in duodenum, jejunum and ileum, respectively (P<0.01). All segments showed stress–strain distributions that were exponential by nature. Applying the function Y=exp(a+bX) gave a median determination coefficient of 0.98 (quartiles 0.96–0.99). The duodenum was significantly stiffer than the two other segments. The values of a and b were 2.03±0.11 and 14.82±1.81, 1.39±0.20 and 13.15±1.42, and 1.13±0.13 and 10.69±0.65 for the duodenum, jejunum and ileum, respectively. The a differed between the duodenum and the other segments (P<0.001), whereas the b differed only between the duodenum and ileum (P<0.005). In conclusion, differences in the luminal CSA, wall thickness and elastic properties were found between the duodenum, jejunum and ileum.
Drifting vortices of electrical waves underlie ventricular fibrillation in the rabbit heart
Authors: JALIFE J. , GRAY R.
Published: October 2003

Ventricular fibrillation is the most important cause of cardiac electrical instability leading to sudden death. Fibrillation is believed to be associated with complex three‐dimensional (3‐D) spatio‐temporal patterns of electrical excitation of the myocardium. However, to this date, such patterns have not been directly observed or characterized, and little is known about their dynamics. In this paper, we present results that strongly support the hypothesis that at least some cases of ventricular fibrillation in the structurally normal heart may be the result of a single 3‐D electrical scroll wave that moves rapidly throughout the ventricles, giving rise to complex patterns of cardiac muscle excitation.
Neuropeptide Y regulates rat renal tubular Na,K‐ATPase through several signalling pathways
Authors: OHTOMO Y. , ONO S. , ZETTERGREN E. , SAHLGREN B.
Published: October 2003

Neuropeptide Y (NPY) has at least three receptors (Y1, Y2 and Y3) through which it influences different mechanisms in many cell types. Previous data suggest that the Y2 receptor may be divided into prejunctional and postjunctional subgroups. We have examined the intracellular signalling pathways of the postjunctional Y2 receptor in rat renal proximal tubules. The results indicate that NPY regulates Na+,K+‐ATPase through several signalling pathways: (1) In proximal tubule (PT) cells NPY increased intracellular calcium. The response was blocked by removing extracellular calcium and was also blocked by using nifedipine. This suggests that calcium was increased by influx from the extracellular space through L‐type calcium channels. (2) NPY increased Na+,K+‐ATPase activity in PT segments and this effect was also blocked by nifedipine. CaMKII‐Ala286[281–302] a blocker of Ca2+/calmodulin‐dependent protein kinase II (CaMKII) inhibited the NPY‐stimulated Na+,K+‐ATPase activity. This implies that increased intracellular calcium activates CaMKII which subsequently increases Na+,K+‐ATPase activity. CaMKII thus appear to act similar to what has been proposed for protein phosphatase 2B. (3) Calphostin C, an inhibitor of protein kinase C (PKC), did not inhibit NPY‐stimulated Na+,K+‐ATPase activity. PKC is, therefore, unlikely to be involved. (4) Y2 receptors are negatively coupled to the cAMP pathway. NPY attenuated forskolin‐stimulated cAMP production in renal tubules and exogenous cAMP counteracted the NPY‐stimulated Na+,K+‐ATPase activity. This illustrated the importance of NPY for the regulation of renal sodium handling. We also propose that the renal tubule cell is a good model for studying the function and mechanisms of postjunctional Y2 receptors.
Analysis of leak current properties in the lobster stretch receptor neurone
Authors: THEANDER S. , FÅHRÆUS C. , GRAMPP W.
Published: October 2003

Experiments were performed to characterize the so‐called leak current of the slowly adapting stretch receptor neurone of the European lobster with respect to its ionic basis, its kinetics and its pharmacology. Estimates of the leak current were obtained by subtraction of a Na‐K pump current and of an unspecific impalement current from a non‐dynamic (‘instantaneous’) current, recorded in a voltage range from ∼‐120 to ∼‐30 mV, after blockage of spike‐generating currents and a hyperpolarization‐activated inwardly rectifying current (Q‐current). The leak current, estimated in this way, was seen to reverse direction at the cell's K+ equilibrium voltage, thus indicating that it is carried by K+ passing through channels which, also, proved to be permeable to Rb+ and NH4+, but not permeable to Na+ or Cl‐ to any significant extent. Kinetically, the leak current was found to be characterized by being enhanced by increases in extracellular K+ and by being subject to outward rectification, most distinctly at elevated extracellular [K+]. In quantitative terms, these kinetic properties could be accounted for by a mathematical model comprising (1) a one‐site two‐barrier Eyring formulation describing ion permeation through membrane channels and (2) an ordinary dose–response relationship describing the channel‐opening effect of K+ at an extracellular regulatory site. Pharmacologically, the leak current proved to be distinguished by being reversibly blockable, in a non‐voltage dependent manner, by Co2+ (Kd=0.9 mm, Hill coefficient 1.1) and procaine, but not by Ba2+, Gd3+, bupivacaine (a local anesthetic), or other K+ channel blockers such as TEA, 4‐AP and Cs+. It is concluded that, in native unimpaled cells, the K+ carried leak current (1) is setting the resting voltage together with the (mainly) Na+‐carried Q‐current and the Na‐K pump current, (2) is determining the cell's firing threshold, together with the spike generating currents, and (3) is also stabilizing the cell's membrane excitability in conditions of varying extracellular [K+], by virtue of its K+ sensitivity.
Hsp70 expression in human skeletal muscle after exercise
Authors: PUNTSCHART A. , VOGT M. , WIDMER H. R. , HOPPELER H. , BILLETER R.
Published: October 2003

Prolonged exercise of a sufficiently high intensity is thought to create physiological stress and to disturb cellular homeostasis, ultimately inducing cellular adaptations which enable the organism to better deal with any future exercise challenge. Heat shock proteins (hsp) are expressed when cells are exposed to different types of stress. In this study, we have investigated whether the expression of the heat inducible form of hsp70 is increased in human skeletal muscle cells after a single bout of exercise. Five untrained subjects performed an exercise bout at their individual anaerobic threshold for 30 min on a treadmill. Hsp70 mRNA concentration was significantly increased by a factor of four at 4 min post‐exercise. Similarly high levels were also observed 30 min and 3 h after the end of exercise. Hsp70 protein concentration, on the contrary, did not change within 3 h after cessation of exercise. Thus, a single exercise bout in humans is able to increase the steady state concentration of hsp70 mRNA, but is probably not sufficient to have an effect on the already high basal level of its protein. The analysis of hsp70 mRNA is potentially useful as a method to detect stress in tissues with a high basal level of heat shock proteins.
VIP‐antiserum and indomethacin inhibit calcium and bicarbonate secretion by the inflamed feline gallbladder mucosa
Authors: NILSSON B. , DELBRO D. , THUNE A. , FRIMAN S. , JIVEGÅRD L. , SVANVIK J.
Published: October 2003

Ionized calcium (Ca2+) and bicarbonate (HCO3‐) are important ions for gallstone formation. In the present study the effect of indomethacin and vasoactive intestinal peptide‐antiserum (VIP‐antiserum) on the Ca2+, HCO3‐ and fluid secretion in the inflamed gallbladder were tested in a validated experimental model in cats. The animals were studied in acute experiments 6 weeks after cystic duct ligation and gallstone implantation. During basal conditions there was a continuous secretion of Ca2+, HCO3‐ and fluid into the lumen of the inflamed gallbladder. Indomethacin and VIP‐antiserum inhibited the Ca2+, HCO3‐ and fluid secretion across the inflamed gallbladder mucosa. Intraluminal amiloride inhibited the absorption of Ca2+, HCO3‐ and fluid after indomethacin infusion. An impaired absorption of Ca2+, HCO3‐ and fluid in the inflamed gallbladder is probably important for the solubility of calcium salts in the early stages of inflammation in the gallbladder mucosa.
High afterload during 10 min of regional ischaemia affects diastolic creep but not systolic function in reperfused (stunned) myocardium
Authors: RYNNING S. E. , BRUNVAND H. , BIRKELAND S. , HEXEBERG E. , GRONG K.
Published: October 2003

The effect of afterload during regional ischaemia on myocardial stunning was studied in 15 pentobarbital anaesthetized cats. 10 min occlusion of the left anterior descending artery (LAD) was followed by 60 min of reperfusion. Afterload was decreased by intravenous infusion of nitroglycerine 3–8 μg kg‐1 min‐1 in group I (n=8); left ventricular peak systolic pressure (LVSP) 84±4 mmHg (mean±SEM) during coronary artery occlusion. In group II (n=7) LVSP was increased to 188±10 mmHg by inflating an intraaortic balloon during coronary artery occlusion. Regional function in the LAD perfused region was evaluated by cross‐oriented sonomicrometry. Myocardial tissue blood flow was evaluated by radio‐labelled microspheres. Afterload alterations did not affect regional systolic shortening (10.8±2.0% vs. 11.0±1.5% in group I and II, respectively, after 60 min of reperfusion). However, increased end‐diastolic dimensions (diastolic creep) in both the circumferential and longitudinal segments were markedly more pronounced in the high afterload group (group II). Also important, the markedly increased myocardial tissue blood flow during reperfusion in group II as compared with group I (2.30±0.18 vs.  1.34±0.08 mL min‐1 g‐1 and 2.58±0.23 vs. 1.49±0.07 mL min‐1 g‐1 in subepicardial and subendocardial layers in the LAD perfused region) suggests that increased diastolic creep increased metabolic demands. This study indicates that passive stretching of the ischaemic area during coronary artery occlusion is an important mechanism behind diastolic creep.
Rapid plasma volume decline upon quiet standing reflects large filtration capacity in dependent limbs
Authors: LUNDVALL J. , BJERKHOEL P. , QUITTENBAUM S. , LINDGREN P.
Published: October 2003

The plasma volume (PV) decline upon 1.5, 3, 5, 8, 10, 15 and 35 min periods of quiet standing was studied (Hb/Hct) in male volunteers (n=7). This approach permitted detailed definition of the time‐course of the volume change. PV decreased by as much as 8.5±0.4% (328±15 mL) after 3 min standing and by no less than 11.7±0.4% (466±22 mL) after 5 min. The reduction was 14.3±0.7, 16.8±0.8, 17.7±0.8 and 17.4±0.9% after 8, 10, 15 and 35 min, or 568±30, 671±39, 707±41 and 691±44 mL. These data, in conjunction with the 1.5 min experiments, indicated a very rapid≈125 mL min‐1 fluid loss initially on standing. However, the PV loss showed marked decline with time and was virtually completed within 10 min. Finally, the observation was made that the rate of PV recovery after standing was inversely related to the duration of standing. It is suggested that (a) the transcapillary hydraulic conductivity in the dependent limbs, the predominant targets for fluid filtration on standing, is about 0.010 mL min‐1 100 mL‐1 mmHg‐1 and much greater than indicated previously. However, protective mechanisms restrict rapid fluid loss to early phases of standing. (b) Decrease in PV may contribute importantly to haemodynamic stress and to orthostatic, fainting reactions during short quiet standing. Apparently, PV loss may be equally important as pooling of blood, traditionally regarded as a dominant cause of adverse orthostatic reactions. (c) The duration of standing, as such, may be critical for the rate of PV recovery after standing.
Pancreastatin modulates glucose‐stimulated insulin secretion from the perfused rat pancreas
Authors: AHRÉN B. , BERTRAND G. , ROYE M. , RIBES G.
Published: October 2003

Pancreastatin is known to be produced in islet B cells and to inhibit insulin secretion. In this study, we examined whether the peptide affects insulin secretion from the perfused rat pancreas during raising or lowering the glucose concentration within the physiological range. We found that synthetic porcine pancreastatin (15 nmol L‐1) significantly inhibited the first phase (5 min) of insulin release induced by raising the glucose concentration from 4.2 to 8.3 mmol L‐1 (P< 0.05) without affecting the second phase. Furthermore, the fall in insulin secretion induced by lowering the glucose concentration from 8.3 to 5.5 mmol L‐1 was significantly exaggerated in presence of pancreastatin during the first 5 min (P<0.05). In contrast, pancreastatin did not affect the inhibition of insulin secretion induced by either the α2‐adrenoceptor agonist, clonidine (2 nmol L‐1), or the P1‐purinoceptor (A1‐subtype) agonist, N6(+)‐phenylisopropyladenosine (d‐PIA) (1.65 μmol L‐1). In conclusion, our results show that pancreastatin is a modulator of the early changes in insulin secretion after increase or decrease of the glucose concentration within the physiological range. This suggests that pancreastatin is a modulator of glucose‐stimulated insulin secretion.
Ageing reduces sympatho‐suppressive response to head‐out water immersion in humans
Authors: MIWA C. , MANO T. , SAITO M. , IWASE S. , MATSUKAWA T. , SUGIYAMA Y. , KOGA K.
Published: October 2003

Muscle sympathetic nerve activity (MSNA) is suppressed during thermoneutral head‐out water immersion (HOI) in humans. In this study, the effects of ageing on the suppressive response of MSNA to HOI were determined. MSNA was recorded microneurographically from the tibial nerve in 16 healthy men, 10 of whom were aged 19–30 years (young group) and six aged 45–67 years (older group). MSNA was suppressed in all the subjects during HOI. The suppressive response was significantly less prominent in the older group than in the young group. A significant negative correlation between age and the suppressive response of MSNA induced by HOI (r=‐0.53, P<0.05) was found. We conclude that suppressive response of sympathetic nerve activity to HOI is reduced with age.
Changes in fibre types in rat soleus and plantaris muscles following hypophysectomy and compensatory overload
Authors: YAMAGUCHI A. , SAKUMA K. , MORITA I. , SOYA H. , TAKEDA H. , KATSUTA S.
Published: October 2003

We investigated whether hypophysectomy could modify the change in muscle fibre types caused by compensatory overload. Male Wistar strain rats were assigned to groups of either normal control (NC), hypophysectomized control (HC), normal compensatory overloaded (NO), or hypophysectomized compensatory overloaded (HO). Compensatory overload was induced by the bilateral removal of the gastrocnemius muscle. Five weeks later, there were losses in the soleus and plantaris muscle weights as a result of hypophysectomy. Compensatory overload increased muscle weights independently of the hypophysectomy. Growth hormone and 3,5,3′‐triiodothyronine levels were significantly decreased following hypophysectomy. In the soleus, hypophysectomy increased the percentage of type I fibres at the expense of type IIA fibres. Compensatory overload decreased type IIA fibres under the hypophysectomized condition. In the plantris, the percentage of type IIC fibres was increased at the expense of both type IIA and IIB fibres following hypophysectomy. The decrease in type IIB fibres cause by compensatory overload was induced irrespective of hypophysectomy. The changes in muscle fibre types in the HO group were equal to the sum of the changes in the HC and NO groups. These results suggest that after a period of 5 weeks hypophysectomy may induced decreases in type IIA and IIB fibres in association with the lack of pituitary and thyroid hormones, and that the hypophysectomy could not modify the change in muscle fibre types caused by compensatory overload.