bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of mackerel (Scomber scombrus) recruitment with an individual‐based model and comparison with field data
Authors: Bartsch J. , Reid D. , Coombs S. H.
Published: October 2004

An individual‐based model (IBM) for the simulation of year‐to‐year survival during the early life‐history stages of the north‐east Atlantic stock of mackerel (Scomber scombrus) was developed within the EU funded Shelf‐Edge Advection, Mortality and Recruitment (SEAMAR) programme. The IBM included transport, growth and survival and was used to track the passive movement of mackerel eggs, larvae and post‐larvae and determine their distribution and abundance after approximately 2 months of drift. One of the main outputs from the IBM, namely distributions and numbers of surviving post‐larvae, are compared with field data as recruit (age‐0/age‐1 juveniles) distribution and abundance for the years 1998, 1999 and 2000. The juvenile distributions show more inter‐annual and spatial variability than the modelled distributions of survivors; this may be due to the restriction of using the same initial egg distribution for all 3 yr of simulation. The IBM simulations indicate two main recruitment areas for the north‐east Atlantic stock of mackerel, these being Porcupine Bank and the south‐eastern Bay of Biscay. These areas correspond to areas of high juvenile catches, although the juveniles generally have a more widespread distribution than the model simulations. The best agreement between modelled data and field data for distribution (juveniles and model survivors) is for the year 1998. The juvenile catches in different representative nursery areas are totalled to give a field abundance index (FAI). This index is compared with a model survivor index (MSI) which is calculated from the total of survivors for the whole spawning season. The MSI compares favourably with the FAI for 1998 and 1999 but not for 2000; in this year, juvenile catches dropped sharply compared with the previous years but there was no equivalent drop in modelled survivors.
Cellular and molecular studies of B cells exhibiting reverse somatic mutation throughout life
Authors: Kodera Takao , Radu Dorel , McGaha Tracy , Zwolo Patty , Stoica Cristina , Cheroute Hilde , Pollock Roberta R. , Bona Constantin
Published: October 2004

Somatic mutation of immunoglobulin (Ig) genes plays an important role in generating antibody diversity. The frequency of somatic mutation appears to vary throughout life. However, this process has been difficult to study in vivo because the DNA in and around rearranged V genes undergoes random mutation, causing silent or replacement mutations. Therefore, we have developed a transgenic mouse model for studying the frequency of B cells exhibiting mutation in young and old mice. The system is based on a reporter transgene (HuG‐X) that encodes a chimeric Ig heavy chain composed of a murine VDJ segment and a human IgG1 constant region. The VDJ has been mutated to contain a TAG stop codon in the D segment. Therefore, the transgene is transcribed but not translated. Point mutation of the stop codon results in expression of the chimeric H chain, which is readily detected as human IgG1 expression. In vivo, we found that the transgene undergoes spontaneous reverse somatic mutation at a low frequency. Treatment of HuG‐X mice with anti‐IgD greatly increases the frequency of somatic mutation. The observed mutation frequency in anti‐IgD‐treated mice increases with age until adulthood, then plateaux and finally declines in aged mice. The mutations in the stop codon were associated with increased double‐stranded DNA breaks (DSB) within and around the TAG site. Our results demonstrate that the rate of frequency of spontaneous reverse mutation is very low in vivo, yet it is significantly increased after stimulation with anti‐IgD antibodies. The frequency of point mutation is age dependent and correlates with increased DSB.
Induction of apoptosis in a flounder gill cell line by lymphocystis disease virus infection
Authors: Hu G‐B , Cong R‐S , Fan T‐J , Mei X‐G
Published: October 2004

Lymphocystis disease virus (LCDV), a large icosahedral DNA virus classified to the iridovirus family, is the causative agent of lymphocystis, a disease which occurs in marine and freshwater fish species and is characterized by formation of papilloma‐like lesions on the surface of the skin. In vitro, LCDV infection causes flounder gill cells, an adherent cell line, to exhibit an obvious cytopathic effect (CPE). In order to test whether apoptosis is responsible for the observed CPE, cells infected with LCDV at a multiplicity of infection (m.o.i.) of 5 PFU per cell were examined at various time intervals for the appearance of apoptotic signs. Nuclear fragmentation, DNA laddering and caspase activation were observed in the infected cells at the time (i.e. 10 days post‐infection) when an intensive CPE was observed. These findings demonstrate that LCDV is capable of inducing apoptosis in vitro, which is different from the result of LCDV infection in vivo, and consequently suggest an intricate LCDV–host interaction.
Comparison between mitochondrial and chloroplast DNA variation in the native range ofSilene vulgaris
Authors: ŠTORCHOVÁ HELENA , OLSON MATTHEW S.
Published: October 2004

A detailed survey of mitochondrial and chloroplast diversity in eight populations ofSilene vulgarisfrom Central Europe was conducted for comparison with previously published data on diversity fromS. vulgarispopulations in the introduced range. Mitochondrial DNA (mtDNA) variation around thecoxIgene was assessed with Southern blotting/restriction fragment length polymorphism methods. Chloroplast variation was assessed by sequencing the intergenic spacer separating thetrnHandpsbAgenes. Thirty mtDNA haplotypes and 24 chloroplast DNA (cpDNA) haplotypes were found within 86 individuals. The overall genetic diversityh(0.941 for mitochondrial, and 0.893 for chloroplast markers) and within‐population diversity were higher than reported in previous population studies ofS. vulgarisin the USA and Europe. The frequency of private alleles was surprisingly high — more than 90% for both kinds of markers. Most of our populations were large and located in relatively undisturbed meadows, whereas surveys in Virginia consisted of smaller roadside populations. The slow rate of population turnover in European populations is discussed as a factor responsible for the relatively high diversity ofS. vulgarisin undisturbed areas of its native range. Association between mtDNA and cpDNA haplotypes was also demonstrated. Finally, gender and mtDNA haplotype were associated in the Alps populations, where females were very rare.
Fluid resuscitation from severe hemorrhagic shock using diaspirin cross‐linked hemoglobin fails to improve pancreatic and renal perfusion
Authors: Pape A. , Kleen M. , Kemming G. , Meisner F. , Meier J. , Habler O.
Published: October 2004

Background:  Fluid resuscitation from hemorrhagic shock is intended to abolish microcirculatory disorders and to restore adequate tissue oxygenation. Diaspirin cross‐linked hemoglobin (DCLHb) is a hemoglobin‐based oxygen carrier (HBOC) with vasoconstrictive properties. Therefore, fluid resuscitation from severe hemorrhagic shock using DCLHb was expected to improve perfusion pressure and tissue perfusion of kidneys and pancreas.

Methods:  In 20 anesthetized domestic pigs with an experimentally induced coronary stenosis, shock (mean arterial pressure 45 mmHg) was induced by controlled withdrawal of blood and maintained for 60 min. Fluid resuscitation (replacement of the plasma volume withdrawn during hemorrhage) was performed with either 10% DCLHb (DCLHb group, n = 10) or 8% human serum albumin (HSA) oncotically matched to DCLHb (HSA group, n = 10). Completion of resuscitation was followed by a 60‐min observation period. Regional blood flow to the kidneys and the pancreas was measured by use of the radioactive microspheres method at baseline, after shock and 60 min after fluid resuscitation.

Results:  All animals (10/10) resuscitated with DCLHb survived the 60‐min observation period, while 5/10 control animals died within 20 min due to persisting subendocardial ischemia. In contrast to HSA survivors, pancreas and kidneys of DCLHb‐treated animals revealed lower total and regional organ perfusion and regional oxygen delivery. Renal and pancreatic blood flow heterogeneity was higher in the DCLHb group.

Conclusion:  DCLHb‐induced vasoconstriction afforded superior myocardial perfusion, but impaired regional perfusion of the kidneys and the pancreas.
Intrathecal adenosine increases spinal cord blood flow in the rat: measurements with the laser‐Doppler flowmetry technique
Authors: Rane K. , Segerdahl M. , Karlsten R.
Published: October 2004

Background:  Adenosine and adenosine analogues induce antinociception both after systemic and intrathecal (i.t.) administration in animal models. Further, patients with neuropathic pain have been treated successfully with i.t. adenosine. Prior to introducing new analgesic drugs for regular spinal use in humans, experimental studies must be undertaken to evaluate the risks of neurotoxicity. It is important to evaluate the possibility of cytotoxic effects and that antinociception may be due to decreased spinal cord blood flow (SCBF) and neural ischaemia. The present study evaluates whether adenosine or isotonic mannitol induces changes in SCBF as assessed by laser‐Doppler flowmetry (LDF).

Methods:  After laminectomy and insertion of i.t. catheters, seven rats received adenosine 50 μg in isotonic mannitol 500 μg, six rats received isotonic mannitol 500 μg and eight rats received saline 0.9%. SCBF was registered by the LDF technique continuously for 3 h after injection. Arterial blood pressure was also assessed.

Results:  In the adenosine in mannitol group, SCBF increased up to 230% of baseline levels for almost 40 min, P = 0.044 and then declined. In the mannitol group, SCBF increased up to 180% of baseline (P < 0.011) before declining. At 60 min, SCBF had returned to saline levels and remained stable during the rest of the experiment.

Conclusion:  Intrathecal administration of adenosine in mannitol and of mannitol both increased SCBF in rats, compared with saline. It is unlikely that the effects on SCBF induced by adenosine and mannitol could result in neurotoxicity of the spinal cord.
Low‐dose bupivacaine with sufentanil prevents hypotension after spinal anesthesia for hip repair in elderly patients
Authors: Olofsson C. , Nygårds E‐B. , Bjersten A‐B. , Hessling A.
Published: October 2004

Background:  Hip fracture is common in the geriatric population. Patients in this group are often at high risk for perioperative complications from concurrent diseases. Conventional spinal anesthesia can be associated with hypotension but has a better postoperative outcome compared to general anesthesia. We judged that a reduced dose of bupivacaine in combination with sufentanil could give reliable blocks with minimal hypotension.

Methods:  Fifty elderly patients were randomized into two groups. The study group received spinal anesthesia as a combination of hyperbaric bupivacaine 7.5 mg and sufentanil 5 µg while the control group received hyperbaric bupivacaine 15 mg. The hemodynamic stability of the patients and the quality of the blocks were compared.

Results:  All patients had adequate duration of reliable blocks. More control group patients than study group patients required ephedrine due to hypotension.

Conclusion:  A reduced dose of hyperbaric bupivacaine (7.5 mg) in combination with sufentanil (5 µg) provides reliable spinal anesthesia for the repair of hip fracture in aged patients with few events of hypotension and little need for vasopressor support of blood pressure.
Effects of subanaesthetic and anaesthetic doses of sevoflurane on regional cerebral blood flow in healthy volunteers. A positron emission tomographic study
Authors: Schlünzen L. , Vafaee M. S. , Cold G. E. , Rasmussen M. , Nielsen J. F. , Gjedde A.
Published: October 2004

Background:  We tested the hypothesis that escalating drug concentrations of sevoflurane are associated with a significant decline of cerebral blood flow in regions subserving conscious brain activity, including specifically the thalamus.

Methods:  Nine healthy human volunteers received three escalating doses using 0.4%, 0.7% and 2.0% end‐tidal sevoflurane inhalation. During baseline and each of the three levels of anaesthesia one PET scan was performed after injection of . Cardiovascular and respiratory parameters were monitored and electroencephalography and bispectral index (BIS) were registered.

Results:  Sevoflurane decreased the BIS values dose‐dependently. No significant change in global cerebral blood flow (CBF) was observed. Increased regional CBF (rCBF) in the anterior cingulate (17–21%) and decreased rCBF in the cerebellum (18–35%) were identified at all three levels of sedation compared to baseline. Comparison between adjacent levels sevoflurane initially (0 vs. 0.2 MAC) decreased rCBF significantly in the inferior temporal cortex and the lingual gyrus. At the next level (0.2 MAC vs. 0.4 MAC) rCBF was increased in the middle temporal cortex and in the lingual gyrus, and decreased in the thalamus. At the last level (0.4 MAC vs. 1 MAC) the rCBF was increased in the insula and decreased in the posterior cingulate, the lingual gyrus, precuneus and in the frontal cortex.

Conclusion:  At sevoflurane concentrations at 0.7% and 2.0% a significant decrease in relative rCBF was detected in the thalamus. Interestingly, some of the most profound changes in rCBF were observed in structures related to pain processing (anterior cingulate and insula).
Women report more pain on injection of a precurarization dose of rocuronium: A randomized, prospective, placebo‐controlled trial
Authors: Mencke T. , Schreiber J. U. , Knoll H. , Stracke C. , Kleinschmidt S. , Rensing H. , Silomon M.
Published: October 2004

Background:  The purpose of this study was to investigate whether gender influences the perception of pain on injection of rocuronium.

Methods:  In this prospective, placebo‐controlled trial 120 patients were randomized into four groups to receive rocuronium 0.03 mg kg−1 (40 female and 40 male patients) or saline (20 female and 20 male patients). The incidence and severity of the injection pain after administration of the study drug was compared between female and male patients using a numerical rating scale (0–10). Signs of local irritation, i.e. erythema and thrombophlebitis, were assessed up to 48 h after surgery.

Results:  In 26 (32.5%) of the 80 patients receiving rocuronium, pain on injection was observed. This occurred significantly more frequently in the female compared with male patients: 18 (45%) vs. eight (20%), respectively (P = 0.032). The severity was more pronounced in the women than in the men (P = 0.020). The incidence of the rocuronium‐associated pain was significantly increased compared with the Saline groups (P < 0.001). After surgery no patient complained of any residual pain and no local signs were observed in any patient during the study period.

Conclusions:  Women experienced more pain on injection of rocuronium than men, moreover this is an additional evidence for gender‐related differences in pain perception. When rocuronium is used as a precurarization agent, an analgesic pretreatment (e.g. opioids) should be considered, especially for female patients.
Further commentary on Denmark's 1952–53 poliomyelitis epidemic, especially regarding mortality; with a correction
Authors: Trubuhovich R. V.
Published: October 2004

Berthelsen and Cronqvist recently published an article in Acta Anaesthesiologica Scandinavica including aspects which could lead on to further discussion about the Danish 1952–53 poliomyelitis epidemic. This paper considers how Bjørn Ibsen's initial approach to treatment during the epidemic was successful, as well as how it could have failed; the roles played by ventilatory failure vs. gross neurologic destruction in causing deaths; and compilations from publications of statistics concerning mortality of the epidemic.

The Blegdam Hospital concept of ‘life‐threatening poliomyelitis’ is revisited, along with its division into six anatomico‐clinical categories for the 345 patients so classified. Attention is drawn to the severity of assorted cerebral lesions demonstrated in 114 of the 115 autopsies conducted from the 144 fatal cases. Despite an overall mortality rate of 41.6% among the entire epidemic's sickest patients, a lowest mortality rate of 11% in the last 18 of such patients is identified. Note is made of the difficulty in reconciling various sources for certain features – for which the 1956 book on the epidemic, edited by H.C.A. Lassen, has been freely used. Some folklore about aspects of management is mentioned.

In the light of other recent research by Dr Berthelsen an essential correction is needed in dating ‘Bjørn Ibsen's Day', amending 26 August 1952 to the 27th.
Thermodilution cardiac output – are three injections enough?
Authors: Nilsson L. B. , Nilsson J. C. , Skovgaard L. T. , Berthelsen P. G.
Published: October 2004

Background:  Bolus thermodilution cardiac output measurements have been a mainstay in clinical monitoring of critically ill patients for more than 30 years. Usually the results of an arbitrarily chosen number (1–6) of thermal indicator injections are averaged to increase the reliability of the measurement. The number of injections needed to achieve a given level of precision has, however, not previously been systematically investigated.

Methods and results:  In 80 hemodynamically stable patients cardiac output was determined as the average of eight injections of 10 ml of iced saline. From the 638 measurements we examined the relationship between the number of thermal indicator injections and the precision of the resulting cardiac output estimate. Furthermore, the association between the number of injections and the least detectable difference among two sets of measurements was established.

Conclusion:  The current study shows that one needs to average the results of four injections to be 95% confident that the result is within 5% of the ‘true’ cardiac output and that two series of four measurements have to differ by at least 7% before one can be sure (95%) that a change in cardiac function has taken place.
The 118 A > G polymorphism in the human µ‐opioid receptor gene may increase morphine requirements in patients with pain caused by malignant disease
Authors: Klepstad P. , Rakvåg T. T. , Kaasa S. , Holthe M. , Dale O. , Borchgrevink P. C. , Baar C. , Vikan T. , Krokan H. E. , Skorpen F.
Published: October 2004

Background:  Dispositions for genes encoding opioid receptors may explain some variability in morphine efficacy. Experimental studies show that morphine and morphine‐6‐glucuronide are less effective in individuals carrying variant alleles caused by the 118 A > G polymorphism in the µ‐opioid receptor gene (OPRM1). The purpose of the study was to investigate whether this and other genetic polymorphisms in OPRM1 influence the efficacy of morphine in cancer pain patients.

Methods:  We screened 207 cancer pain patients on oral morphine treatment for four frequent OPRM1 gene polymorphisms. The polymorphisms were the −172 G > T polymorphism in the 5′untranslated region of exon 1, the 118 A > G polymorphism in exon 1, and the IVS2 + 31 G > A and IVS2 + 691 G > C polymorphisms, both in intron 2. Ninety‐nine patients with adequately controlled pain were included in an analysis comparing morphine doses and serum concentrations of morphine and morphine metabolites in the different genotypes for the OPRM1 polymorphisms.

Results:  No differences related to the −172 G > T, the IVS2 + 31 G > A and the IVS2 + 691 G > C polymorphisms were observed. Patients homozygous for the variant G allele of the 118 A > G polymorphism (n = 4) needed more morphine to achieve pain control, compared to heterozygous (n = 17) and homozygous wild‐type (n = 78) individuals. This difference was not explained by other factors such as duration of morphine treatment, performance status, time since diagnosis, time until death, or adverse symptoms.

Conclusion:  Patients homozygous for the 118 G allele of the µ‐opioid receptor need higher morphine doses to achieve pain control. Thus, genetic variation at the gene encoding the µ‐opioid receptor contributes to variability in patients' responses to morphine.
Pitfalls and challenges when assessing the depth of hypnosis during general anaesthesia by clinical signs and electronic indices
Authors: Jensen E. W. , Litvan H. , Struys M. , Vazquez P. Martinez
Published: October 2004

The objective of this article was to review the present methods used for validating the depth of hypnosis. We introduce three concepts, the real depth of hypnosis (DHreal), the observed depth of hypnosis (DHobs), and the electronic indices of depth of hypnosis (DHel‐ind). The DHreal is the real state of hypnosis that the patient has in a given moment during the general anaesthesia. The DHobs is the subjective assessment of the anaesthesiologist based on clinical signs. The DHel‐ind is any estimation of the depth of hypnosis given by an electronic device. The three entities DHreal, DHobs and DHel‐ind should in the ideal situation be identical. However, this is rarely the case. The correlation between the DHobs and the DHel‐ind can be affected by a number of factors such as the stimuli used for the assessment of the level of consciousness or the administration of analgesic agents or neuro muscular blocking agents. Opioids, for example, can block the response to tactile and noxious stimuli, and even the response to verbal command could vanish, hence deeming the patient in a lower depth of hypnosis than the real patient state. The DHel‐ind can be disturbed by the presence of facial muscular activity.

In conclusion, although several monitors and clinical scoring scales are available to assess the depth of hypnosis during general anaesthesia, care should be taken when interpreting their results.
Adverse biochemical and physiological effects of prostacyclin in experimental brain oedema
Authors: Gärdenfors F. , Nilsson A. , Ungerstedt U. , Nordström C. H.
Published: October 2004

Background:  Prostacyclin (PGI2) and its stable analogues are known to reduce capillary hydraulic permeability. This study explores the biochemical and physiological effects of i.v. infusion of low‐dose PGI2 in an experimental model of vasogenic brain oedema.

Methods:  Twenty‐seven anaesthetized and mechanically ventilated piglets with brain oedema induced by intrathecal injection of lipopolysaccharide (LPS) were used. Five of the animals received a continuous infusion of PGI2 (1 ng kg−1 min−1) i.v. Four microdialysis catheters were placed in the brain to measure interstitial concentrations of glucose, lactate, and glycerol. Mean arterial pressure (MAP), intracranial pressure (ICP) and temperature were monitored continuously. Low‐dose infusion of PGI2 started 1 h before the LPS injection and was constant during the study period.

Results:  Intracranial pressure increased significantly in animals treated with PGI2. The increase in ICP was associated with significant cerebral biochemical changes: decrease in glucose, increase in lactate, increase in lactate/glucose ratio and increase in glycerol.

Conclusion:  In LPS‐induced brain oedema i.v. infusion of low‐dose PGI2 caused a further increase in ICP and a perturbation of energy metabolism, indicating cerebral ischemia and degradation of cellular membranes.
Rocuronium attenuates oculocardiac reflex during squint surgery in children anesthetized with halothane and nitrous oxide
Authors: Karanovic N. , Jukic M. , Carev M. , Kardum G. , Dogas Z.
Published: October 2004

Background:  The oculocardiac reflex (OCR) may be activated during squint surgery. The aim of this study was to test whether rocuronium 0.4 mg kg−1 could reduce the frequency of OCR, and also whether a single dose of succinylcholine 1 mg kg−1 could affect the frequency of OCR during anesthesia with halothane in a nitrous oxide/oxygen mixture.

Methods:  A total of 161 ASA I children, 3–10 years old, undergoing elective surgery of the medial rectus muscle (MRM) were randomly assigned to three groups. Group R (n = 51), received 0.4 mg kg−1 of rocuronium intravenously before endotracheal intubation. Group S (n = 58) received 1 mg kg−1 of succinylcholine. Group C (controls, n = 52) received no relaxant. Oculocardiac reflex was defined as a reduction in heart rate (HR) >= 15% and/or the appearance of any other arrhythmias, during manipulation of the MRM. Analysis of variance (anova), chi‐squared, Kruskal–Wallis, and Student's t‐tests were used for statistical analysis; P< 0.05 was considered statistically significant.

Results:  In group R, OCR occurred in 15/51 (29%) of children, in group S in 31/58 (53%), and in group C in 23/52 (44%) (χ2 = 6.46, P = 0.049). In group R, the incidence of arrhythmias such as nodal rhythms, supraventricular and ventricular premature beats was 6%, compared with 22% in group S and 19% in group C (χ2 = 6.01, P = 0.040). However, there was no reduction in the occurrence of bradycardia (χ2 = 0.16, P = 0.924).,

Conclusion:  Rocuronium reduced the frequency of OCR, mainly by reducing the incidence of supraventricular and ventricular premature beats.
Comparison of the analgesic efficacy of ketobemidone and morphine for management of postoperative pain in children: a randomized, controlled study
Authors: Jylli L. , Lundeberg S. , Langius‐Eklöf A. , Olsson G. L.
Published: October 2004

Background:  Ketobemidone has been used as an analgesic for postoperative pain in children, but to our knowledge the effect and occurrence of adverse effects of ketobemidone compared to morphine is not known. The aim was to determine if the analgesic potency and the occurrence of adverse effects of ketobemidone differ from morphine when administered to children, as measured by patient‐controlled analgesia consumption (PCA) for postoperative pain.

Methods:  Sixty healthy children, aged 6 to 16 years, scheduled for elective surgery were randomized to receive either ketobemidone (Ke) 1 mg ml−1 or morphine (Mo) 1 mg ml−1 for postoperative pain through PCA. Drug consumption (µg kg−1 h−1), the number of PCA doses, pain intensity, and adverse effects were recorded at regular intervals.

Results:  Data on total drug consumption were based on 26 children in the Ke group and 28 in the Mo group. A non‐statistically significant difference for total mean consumption of ketobemidone (18.6 µg kg−1h−1) and morphine (23.2 µg kg−1h−1) was obtained. The mean dose ratio (Mo/Ke) was 0.80 and the median was 0.94. Children's characteristics, loading dose, PCA doses, VAS scores, and adverse effects showed no significant differences between the groups.

Conclusion:  The analgesic potency and adverse effects of ketobemidone are similar to morphine when used for postoperative pain management in children.
Dixyrazine for the prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy
Authors: Glaser C. , Sitzwohl C. , Wallner T. , Lerche A. , Marhofer P. , Schindler I.
Published: October 2004

Background:  The study assessed the efficacy and safety of dixyrazine, an alternative neuroleptic drug to droperidol, in the prophylaxis of postoperative nausea and vomiting (PONV).

Methods:  A total of 197 patients scheduled for laparoscopic cholecystectomy under general anesthesia were randomized to receive either dixyrazine 10 mg or placebo double‐blinded at the end of surgery. Scores pertaining to PONV episodes, analgetic supply, rescue medication, adverse events and patient satisfaction were collected over the first 2 h in the PACU and the next 22 h in the ward.

Results:  The incidence of PONV over the entire 24‐h period was reduced from 32% in the placebo group to 13% in the dixyrazine group (P≤0.004). The incidence of nausea in the first 2 h was reduced from 15% in the placebo group to 4% in the dixyrazine group (P≤0.02) and from 12% to 5% in the next 22 h. The incidence of emetic episodes was not different between the two groups. Postoperative shivering was significantly less prevalent in the dixyrazine than in the placebo group (2% vs. 13%; P≤0008), and opioid analgesics were required significantly less often (61% vs. 75%; P≤0,01). No significant adverse effects were observed. Patient satisfaction was similar in both groups.

Conclusion:  Prophylactic dixyrazine is an effective, safe, and cheap antiemetic drug for laparoscopic cholecystectomy without involving any significant adverse events.
Betamethasone does not prevent nausea and vomiting induced by ipecacuanha
Authors: Axelsson P. , Thörn S. E. , Wattwil M.
Published: October 2004

Background:  Corticosteroids reduce the incidence of PONV but the mode of action is not known. The purpose of this study was to evaluate if betamethasone has serotonin (5‐HT) antagonistic effects. Ipecacuanha is known to release serotonin and therefore it was used to induce nausea and vomiting. The 5‐HT3 antagonist ondansetron was used as a control substance.

Methods:  In a randomized, double‐blind, cross‐over, placebo‐controlled study 10 healthy male and female volunteers (6 M/4F), mean age 19.5 (18–23) years, mean weight 69.7 (53–84) kg, were studied on three occasions separated by at least 1 week. They were randomly allocated to receive pretreatment with betamethasone 8 mg, ondansetron 8 mg, or normal saline 2 ml as placebo on each occasion, 15 min before oral ingestion of 30 ml of Ipecacuanha syrup. After ingestion of ipecacuanha, vomitings were recorded and the intensity of nausea was estimated with a visual analog scale during 2 h.

Results:  During the first 2 h after ingestion of ipecacuanha nine of the 10 volunteers vomited both after betamethasone and placebo. No volunteer vomited after ondansetron (P < 0.01 vs. betamethasone and placebo). The max VAS for nausea was significantly higher after betamethasone and placebo compared to ondansetron (P < 0.01). There were no statistically significant differences of the max VAS for nausea between betamethasone and placebo.

Conclusion:  This study in volunteers has shown that betamethasone does not prevent nausea and vomiting induced by oral intake of ipecacuanha syrup. As ipecacuanha releases 5‐hydroxytryptamin, it can be concluded that betamethasone does not have 5‐HT3 antagonistic effects.
Similar excitation after sevoflurane anaesthesia in young children given rectal morphine or midazolam as premedication
Authors: Malmgren W. , Åkeson J.
Published: October 2004

Background:  Sevoflurane is a rapid‐acting volatile anaesthetic agent frequently used in paediatric anaesthesia despite transient postoperative symptoms of cerebral excitation, particularly in preschool children. This randomised and investigator‐blinded study was designed to evaluate whether premedication with an opioid might reduce non‐divertible postoperative excitation more than premedication with a benzodiazepine in preschool children anaesthetized with sevoflurane.

Methods:  Ninety‐two healthy two to six year‐old children scheduled for nasal adenoidectomy were randomised to be given rectal atropine 0.02 mg kg−1 together with either morphine 0.15 mg kg−1 or midazolam 0.30 mg kg−1 approximately 30 min before induction and maintenance of sevoflurane anaesthesia. The patient groups were compared pre‐ and postoperatively by repeated clinical assessments of cerebral excitation according to a modified Objective Pain Discomfort Scale, OPDS.

Results:  There were no statistically significant postoperative differences in incidence, extent or duration of excitation between children given morphine or midazolam for premedication, whereas morphine was associated with more preoperative excitation than was midazolam. The study groups did not differ significantly with respect to age, weight, duration of surgery and anaesthesia, and time from tracheal extubation to arrival in and discharge from the postoperative ward.

Conclusion:  In this study morphine for premedication in young children anaesthetized with sevoflurane was associated with similar postoperative and higher preoperative OPDS scores compared with midazolam. These findings indicate that substitution of morphine for midazolam is no useful way of reducing clinical excitation after sevoflurane anaesthesia.
Effect of ephedrine on the onset time of succinylcholine
Authors: Ganidagli S. , Cengiz M. , Baysal Z.
Published: October 2004

Background:  The aim of this study was to evaluate the effect of ephedrine administered prior to induction of anaesthesia on the onset time of succinylcholine for endotracheal intubation.

Methods:  Patients were randomly assigned to receive intravenously (i.v.) either 70 µg kg−1 of ephedrine (Group I; n = 25) or saline (Group II; n = 25) 3 min before induction of anaesthesia. Induction of anaesthesia was provided with propofol 2 mg kg−1 plus remifentanil 1 µg kg−1. Onset time and duration of muscle fasciculation and onset time of succinylcholine were recorded. Intubation was attempted after establishment of 100% thumb relaxation and difficulties were recorded. Heart rate, pulse oxymetry (SpO2) and mean arterial pressure (MAP) were also recorded.

Results:  The onset time of succinylcholine were significantly (P < 0.001) shorter in Group I (26 ± 4 s), when compared with Group II (43 ± 6 s). Patients in Group I were intubated at 49 ± 7 s compared with 68 ± 10 s in Group II. The score of intubation was similar in both groups. Duration of muscle fasciculation was longer in Group II. Heart rate and MAP increased significantly (P < 0.05) after ephedrine injection, compared with the baseline value in Group I.

Conclusions:  The onset time of succinylcholine can be shortened with ephedrine pretreatment.
An extended probabilistic approach of plant vital attributes: an application to European pollen records at 0 and 6 ka
Authors: Gritti E. S. , Gachet S. , Sykes M. T. , Guiot J.
Published: October 2004

Aim  This paper presents a probabilistic method of pollen spectra analysis. The method relies on a pollen taxon characterization using biotic and abiotic plant attribute modes, and their occurrence in a given pollen spectrum at a specific site. This type of analysis can provide an interpretation, which can lead to the reconstruction of the biome and, to an extent, of the abiotic conditions at the site.

Methods  The analysis has been carried out at the European scale using data provided by the European Pollen Database for about 1000 sites. This dataset contains about 50,000 pollen spectra from the last 21 ka. In these spectra, each pollen taxon has been characterized by a set of 10 chosen attributes. These have been selected with regard to their relevance in biome reconstruction, but also on the basis of available literature. By using the probability of occurrence of each taxon in a given pollen spectrum, it is possible to calculate an affinity index for the spectrum to the attribute considered. To overcome difficulties caused by pollen identification in low diversified pollen spectra, a co‐occurrence concept has been used to give more information.

Results  The method has been validated on a set of 1327 modern surface samples by comparing the results to the major climatic and environmental variables that control the distribution of the vegetation. A reconstruction exercise on various characteristics of the plants was then carried out on a 6‐ka dataset. This confirmed previous studies by showing a strong dominance of deciduous forest over most of Europe, related to a milder climate than at present in the north and a wetter and colder climate than at present in the south. By analysing the change in pollen/seed dispersion strategies and the light requirement, we show that the history of vegetation dynamics in relation to human influences can be assessed using this method.

Main conclusions  Our results show that the probabilistic method is an objective tool for pollen assemblage analysis. It allows reconstruction of various characteristics of the vegetation at the continental and global scale for periods and sites with significantly different climate conditions. This method can also be used to compare maps of vegetation attributes for the validation of the new generalized dynamic ecosystems models.
Modelling the distribution and interaction of introduced rodents on New Zealand offshore islands
Authors: Russell James C. , Clout Mick N.
Published: October 2004

Aim  To establish the factors that correlate with the distribution of the four most commonly introduced rodent species on New Zealand offshore islands — ship rat (Rattus rattus), Norway rat (R. norvegicus), Pacific rat or kiore (R. exulans) and house mouse (Mus musculus) — and examine if these distributions are interactive at the archipelago scale.

Location  The 297 offshore islands of the New Zealand archipelago (latitude: 34° S to 47° S; longitude: 166° E to 179° E).

Methods  Data on the distribution of all four introduced rodent species and the characteristics of New Zealand offshore islands were collated from published surveys and maps. The distribution of individual rodent species was regressed on island characteristics using a logistic generalized linear model. Interactions were examined by including the distributions of other rodent species as predictors in models.

Results  All four rodent species appear to be limited by a variety of factors, which differ between species in both number and type. The distribution of ship rats is limited by the most factors, reflecting the extent of its distribution across the archipelago. The distribution of mice is the least explicative. Only the three rat species interacted in their distribution. The distribution of kiore on offshore islands is significantly negatively related to that of ship rats and to a lesser extent Norway rats. The distribution of mice did not appear affected in any way by the number of other rodent species on an island.

Main conclusions  Differences in competitive ability and dispersal allow all four species to inhabit the New Zealand archipelago. Kiore distribution appears to be most limited by ship rat (and to a lesser extent Norway rat) distribution. The distribution of kiore was not found to interact with the distribution of mice on offshore islands, as has been suggested by others. The distribution of mice on offshore islands was difficult to model, which highlights the difficulties in managing this species. Overall the results offer valuable insights for management methods to assist preventing the invasion of offshore islands.
Rarity, commonness, and patterns of species richness: the mammals of Mexico
Authors: Vázquez Luis‐Bernardo , Gaston Kevin J.
Published: October 2004

Aim  To determine whether rare or common species contribute most to overall patterns of spatial variation in extant species richness.

Location  Mexico.

Methods  Using data on the distribution of mammal species across Mexico at a quarter degree resolution, we ranked species from the most widespread to the most restricted (common‐to‐rare) within the study area, and from the most restricted to the most widespread (rare‐to‐common), and generated a sequence of patterns of species richness for increasing numbers of species. At each stage along both series of richness patterns, we correlated the species richness pattern for the subassemblage with that of the full assemblage. This allows comparison of subassemblages of the n most common with the n most rare species, in terms of how well they match the full assemblage richness pattern. Further analyses examined the effects on these patterns of correlation of the amount of raw information contained in the distributions of given numbers of rare and common species.

Results  For the mammals of Mexico the more widely distributed species contribute disproportionately to patterns of species richness compared with more restricted species, particularly for non‐volant species and endemic species. This is not simply a consequence of differences in the volumes of information contained in the distributions of rare and common species, with the disproportionate contribution of common species if anything being sharpened when these differences are taken into account. The pattern is most clearly demonstrated by endemic species, suggesting that the contribution of common species is clearest when the causes of rarity and commonness are limited to those genuinely resulting in narrow and widespread geographical ranges, respectively, rather than artificial (e.g. geopolitical) boundaries to the extents of study regions.

Conclusions  Perhaps surprisingly, an understanding of the determinants of overall patterns of species richness may gain most from consideration of why common species occur in some areas and are absent from others, rather than consideration of the distributions of rare species.
The carrying capacity of ecosystems
Authors: Del Monte‐Luna Pablo , Brook Barry W. , Zetina‐Rejón Manuel J. , Cruz‐Escalona Victor H.
Published: October 2004

We analyse the concept of carrying capacity (CC), from populations to the biosphere, and offer a definition suitable for any level. For communities and ecosystems, the CC evokes density‐dependence assumptions analogous to those of population dynamics. At the biosphere level, human CC is uncertain and dynamic, leading to apprehensive rather than practical conclusions. The term CC is widely used among ecological disciplines but remains vague and elusive. We propose the following definition: the CC is ‘the limit of growth or development of each and all hierarchical levels of biological integration, beginning with the population, and shaped by processes and interdependent relationships between finite resources and the consumers of those resources’. The restrictions of the concept relate to the hierarchical approach. Emergent properties arise at each level, and environmental heterogeneity restrains the measurement and application of the CC. Because the CC entails a myriad of interrelated, ever‐changing biotic and abiotic factors, it must not be assumed constant, if we are to derive more effective and realistic management schemes. At the ecosystem level, stability and resilience are dynamic components of the CC. Historical processes that help shape global biodiversity (e.g. continental drift, glaciations) are likely drivers of large‐scale changes in the earth's CC. Finally, world population growth and consumption of resources by humanity will necessitate modifications to the paradigm of sustainable development, and demand a clear and fundamental understanding of how CC operates across all biological levels.
ENDOGENOUS EXPORT SUBSIDIES AND WELFARE UNDER DOMESTIC COST HETEROGENEITY
Authors: Bandyopadhyay Subhayu , Park Eun‐Soo , Wall Howard J.
Published: October 2004

We present a model of international market share rivalry where the domestic export subsidy is determined by lobbying. Greater domestic cost heterogeneity leads to a higher subsidy level and a larger domestic market share. However, the relationship between cost heterogeneity and welfare is ambiguous. Starting from a near‐symmetric situation, an increase in heterogeneity reduces domestic welfare if the number of domestic firms exceeds some critical value. When starting farther from symmetry, the welfare effect is reversed. Our findings are in contrast with the results from the existing literature where lobbying is ignored.
Annual General Meetings of NHS Trusts: Devolving Power or Ritualising Accountability?
Authors: Hodges Ron , Macniven Louise , Mellett Howard
Published: October 2004

This paper provides evidence of the inability of UK NHS trusts to stimulate attendance at their AGMs and that attendance is statistically unrelated to published measures of trusts’ financial results or performance ratings. Evidence is presented of attendance and procedures at trust AGMs and comparisons are made with the private sector. Concepts of power and ritual are applied to the discussion of the results. The findings suggest that the AGM is disconnected from other NHS governance mechanisms. This has implications for both the general concept of empowering stakeholders in the NHS and for specific local empowerment proposals such as the creation of NHS Foundation Trusts.
Investigating the independent evolution of the size of floral organs via G‐matrix estimation and artificial selection
Authors: Delph Lynda F. , Frey Frank M. , Steven Janet C. , Gehring Janet L.
Published: October 2004

Summary
The attractiveness of a plant to pollinators is dependent on both the number of flowers produced and the size of the petals. However, limiting resources often result in a size/number trade‐off, whereby the plant can make either more flowers or larger flowers, but not both. If developmental genes underlying sepal and petal identity (some of which overlap) also influence size, then this shared genetic basis could constrain the independent evolution of floral size and attractiveness. Here, we determined whether the size of sepals and petals in the dioecious perennial, Silene latifolia, are developmentally independent by performing two experiments: a genetic variance–covariance experiment to estimate genetic correlations between calyx width, petal‐limb length, flower mass, and number and a four‐bout artificial‐selection experiment to alter calyx width and estimate the correlated response in petal‐limb length. In addition, we determined whether variation in petal‐limb length is the result of cell expansion or cell proliferation. The first experiment revealed that petal‐limb length is not genetically correlated with calyx width, and the second experiment confirmed this; selection on calyx width did not result in a predictable or significant change in petal‐limb length. Flower number was negatively correlated with all the floral traits measured, indicating a flower size/number trade‐off. Cell number, but not size, explained a significant amount of the variation in petal‐limb length. We conclude that the size of the two outer floral organs can evolve independently. This species can therefore increase the number of flowers produced by decreasing investment in the calyx without simultaneously decreasing petal size and the attractiveness of each individual flower to pollinators.
Synergism between Amodiaquine and Its Major Metabolite, Desethylamodiaquine, againstPlasmodium falciparumIn Vitro
Authors: Mariga S. T. , Gil J. P. , Sisowath C. , Wernsdorfer W. H. , Björkman A.
Published: October 2004

The in vitro activity of the prodrug amodiaquine and its metabolite monodesethyl-amodiaquine has been studied for three strains ofPlasmodium falciparum: LS-2, LS-3, and LS-1. Both compounds showed significant activity against all three strains; the activity of amodiaquine was slightly higher than that of the metabolite. By use of a checkerboard design, interaction studies with both compounds yielded evidence of significant synergism; means of the sums of the fractional inhibitory concentrations were 0.0392 to 0.0746 for strain LS-2, 0.1567 to 0.3102 for strain LS-3, and 0.025 to 0.3369 for strain LS-1. In further investigations, the interaction of amodiaquine with monodesethyl-amodiaquine was tested at clinically relevant concentrations of both compounds. In these studies, involving amodiaquine at picomolar and femtomolar concentrations, the compound was found to exert high potentiating activity on monodesethyl-amodiaquine. This interaction produced mean ratios of observed to expected activity of 0.0505 to 0.0642 for strain LS-2, 0.0882 to 0.3820 for strain LS-3, and 0.0752 to 0.2924 for strain LS-1. The synergistic activity was most marked at monodesethyl-amodiaquine/amodiaquine ratios up to 100,000:1 but was still evident at higher ratios.