bluuebunny/crossref_metadata_2025 huggingface dataset:
Variability and specialization of plant–pollinator systems in a northern maritime grassland
Authors: NAKANO CHIKA , WASHITANI IZUMI
Published: May 2003

To detect plant specialization to pollinator insects and to further examine the ‘pollination syndrome’ hypotheses, flowering angiosperms and insect visitors were recorded in a northern maritime grassland community. Associations between plant species and insect groups were analyzed using binomial tests based on census data obtained from two sites over 3 years. ‘Preference to an insect group by a plant species’ was expressed as a significant deviation of the actual proportion (i.e. the proportion of the number of flower visits by the insect group to the plant species in the total number of visits to the plant species) of the expected proportion (i.e. the proportion of the number of visits by the insect group in the total visits during its flowering period). ‘Preference to a plant species by an insect group’ was similarly expressed using the number of flowers of the plant species visited by the insect group. Most significant preferences varied temporally or spatially. Variability in the preferences is suggested to have resulted from temporal and spatial variations in the abundance and species composition of both flowers and insects. However, in species showing variable preferences, significant specialization in the pollinator insect group (i.e. relatively constant, mutual preferences) were demonstrated for seven and five plant species at the two study sites, respectively. Most specializations were found in associations with bumblebees. ‘Bumblebee specialists’ were significantly well represented in the flower shape types ‘gullet’ and ‘flag’ and the flower color types ‘violet’, which supports the ‘pollination syndrome’ theory.
Effects of sex and age of a dioecious tree, Forchhammeria pallida (Capparaceae) on the performance of its primary herbivore, Murgantia varicolor (Hemiptera: Pentatomidae)
Authors: HENDRICKS BONNIE J. , COLLIER BOYD D.
Published: May 2003

The effects of sex and age of a dioecious tree, Forchhammeria pallida, on the survival and development of a Mexican harlequin bug, Murgantia varicolor, were examined. In the laboratory, bugs reared on fruits or fruits and leaves developed rapidly and had a high rate of survivorship, whereas bugs reared on leaves alone developed slowly after the second instar and died by the fifth instar. Murgantia varicolor showed a preference for leaves from juvenile plants over leaves from mature plants, and bugs reared on leaves from juvenile plants survived significantly longer than those reared on leaves from mature plants. Murgantia varicolor showed no preference for feeding on leaves of mature male versus mature female plants. In the field, M. varicolor occurred on male, female and juvenile plants. Although nymphs were less common on male than female F. pallida, their presence in substantial numbers shows that M. varicolor oviposits on both male and female plants. However, adult M. varicolor were rare on male plants. This result is supported by the inability of nymphs to complete their development on vegetative parts of F. pallida in the laboratory. These observations suggest that dioecy in F. pallida may be disruptive to populations of M. varicolor.
Significance of rooting depth in mire plants: Evidence from natural 15N abundance
Authors: KOHZU AYATO , MATSUI KIYOSHI , YAMADA TOMOYASU , SUGIMOTO ATSUKO , FUJITA NOBORU
Published: May 2003

Variation in stable nitrogen isotope ratios (δ15N) was assessed for plants comprising two wetland communities, a bog‐fen system and a flood plain, in central Japan. δ15N of 12 species from the bog‐fen system and six species from the flood plain were remarkably variable, ranging from −5.9 to +1.1‰ and from +3.1 to +8.7‰, respectively. Phragmites australis exhibited the highest δ15N value at both sites. Rooting depth also differed greatly with plant species, ranging from 5 cm to over 200 cm in the bog‐fen system. There was a tendency for plants having deeper root systems to exhibit higher δ15N values; plant δ15N was positively associated with rooting depth. Moreover, an increasing gradient of peat δ15N was found along with depth. This evidence, together with the fact that inorganic nitrogen was depleted under a deep‐rooted Phragmites australis stand, strongly suggests that deep‐rooted plants actually absorb nitrogen from the deep peat layer. Thus, we successfully demonstrated the diverse traits of nitrogen nutrition among mire plants using stable isotope analysis. The ecological significance of deep rooting in mire plants is that it enables those plants to monopolize nutrients in deep substratum layers. This advantage should compensate for any consequential structural and/or physiological costs. Good evidence of the benefits of deep rooting is provided by the fact that Phragmites australis dominates as a tall mire grass.
Use of foliar 15N and 13C abundance to evaluate effects of microbiotic crust on nitrogen and water utilization in Pinus massoniana in deteriorated pine stands of south China
Authors: Tateno Ryunosuke , Katagiri Shigeo , Kawaguchi Hideyuki , Nagayama Yasuhide , Li Changhua , Sugimoto Atsuko , Koba Keisuke
Published: May 2003

We compared the foliar δ15N and δ13C values of Pinus massoniana growing on soils with and without microbiotic crust to examine the influence of the microbiotic crust on N and water use in plants in deteriorated watersheds in southern China. At our study site, litterfall and undergrowth had been intensively removed for fuel and soil N concentration was extremely low. Microbiotic crust covered the lower slope within the watersheds and pine trees were taller here than on the middle and upper slopes, although the crust reduced the amount of rainfall that could penetrate the soil. The foliar δ15N values were greater (closer to zero) in pine trees growing on soil covered with microbiotic crust on the lower slope than on the middle and upper slopes, which lacked the microbiotic crust. These data suggest that P. massoniana may depend on N fixed by the microbiotic crust on the lower slope, and on N carried by precipitation on the middle and upper slopes. The microbiotic crust did not influence foliar δ13C, an index for water use efficiency, in P. massoniana. The fact that P. massoniana biomass was greater on the lower slope, which is less permeable to rainfall, suggests that P. massoniana growth may be limited by the amount of available N rather than by water. The microbiotic crust may improve plant productivity by increasing N availability, despite its negative effect on water availability.
How does fertility of the substrate affect intraspecific competition? Evidence and synthesis from self‐thinning
Authors: Morris E. Charles
Published: May 2003

When dense populations of even‐aged plant monocultures are subject to intense competition, mortality can occur in a process known as self‐thinning, in which changes in biomass are accompanied by decreases in density. On a plot of log biomass versus log density, self‐thinning populations show a linear relationship called the self‐thinning line. Variations in the fertility level of the substrate are known to affect self‐thinning in a number of ways. Populations from substrates with different fertility levels have been observed to self‐thin along the same line, or along different lines. A review of several experiments using the one species grown at different fertility levels was undertaken to look for any mechanisms that might account for the different patterns observed. It was postulated that the critical difference between whether populations followed a common or different line was the way in which competition developed in the stands as biomass accumulated. For the common‐line pattern, data on the canopy volume required to support a given biomass showed that biomass packing did not differ between fertility levels, supporting the model of a common competitive mechanism operating at all fertility levels. When different lines were observed, the development of competition differed as plants increased in size and biomass accumulated at each fertility level. Over the upper range of fertility levels, biomass packing values per plant increased as fertility declined and the position of self‐thinning lines followed predictions from biomass packing data. At the low end of the fertility scale, biomass packing values still decreased with fertility level, but the position of self‐thinning lines was not linked to the biomass packing of individual plants: root interactions were presumed to dominate competition and the trajectory of self‐thinning lines.
Effects of tidewater on the feeding ecology of hooded crane (Grus monacha) and conservation of their wintering habitats at Chongming Dongtan, China
Authors: Ma Zhijun , Li Bo , Jing Kai , Zhao Bin , Tang Shimin , Chen Jiakuan
Published: May 2003

Dongtan (or East Tideland) on Chongming Island in China is an important wintering site of Grus monacha (hooded crane). Field observations were conducted in Dongtan in the wintering season of 2000–2001 to determine how tidal fluctuation affects the habitat use and behavior of G. monacha. Scirpus mariqueter (sea‐bulrush) was the dominant species in the tidal vegetation; and its corms were the major food source for G. monacha. The corms in the outer zone (far from the dyke) were buried underground shallower than those in the inner zone (near the dyke) because of erosion by tidewater. For easy access to food, G. monacha tended to select the outer zone and the edge of tidal creeks as its foraging sites for the majority of time spent on the tideland. Regression analysis revealed that distance of the foraging sites to the dyke was correlated with tidal height. The cranes did not appear to show territorial behavior, and tended to form large‐sized flocks, especially at high tide, because of the effect of the tidewater and the non‐uniform distribution of food. Thus, the height of the tide is an important factor responsible for the habitat selection of G. monacha, which was also the major cause of the cranes selecting only the natural tideland at Dongtan on Chongming Island. Unfortunately, the habitats of G. monacha are limited, and even threatened, at Dongtan because the tideland is frequently reclaimed. Appropriate measures should be taken to prevent the tideland being further reclaimed, otherwise the natural wintering grounds of G. monacha will soon disappear.
Use of mires and food habits of sika deer in the Oze Area, central Japan
Authors: Takatsuki Seiki
Published: May 2003

Sika deer Cervus nippon entered the Oze Area, a snowy area in central Japan, in the 1990s. The use of mires and the food habits of this species were studied in 1999 and 2000. Deer used the mires immediately after snow melted and did not use the mires in mid summer, although they did use them lightly in autumn. The summer food habits differed from those of the deer population living in Nikko in the lower area: non‐Sasa graminoids and other monocotyledonous leaves occupied more (approximately 30%) of the feces in the former population, whereas Sasa nipponica, a dwarf bamboo, was the dominant food (60%) of the latter population. Seasonal changes in fecal composition in the Oze deer were that mire graminoids occupied a considerable portion of their food in spring (11.6%) and summer (17.0%), whereas the amount of dwarf bamboo increased in fall (26.0%). Despite the small size of the mires, Oze deer appear to prefer mires to forests. Nitrogen concentrations of the mire plants did not differ from those of the forest plants; however, foraging efficiency would be greater in the mires and this may explain the preference observed. Despite the small total biomass, leaf biomass of the mire was equivalent to that of the adjacent forest floor. In addition, biomass was concentrated near the ground, or the ‘biomass concentration’ was greater than that of the forest floor.
Counselling groups for spouses of elderly demented patients: A qualitative evaluation study
Authors: Brännström Benny , Tibblin Åsa , Löwenborg Carin
Published: May 2003

Ten women and eight men who were caring for their demented husbands or wives participated in a closed‐group counselling programme, developed and carried out by two district nurses at a local health centre. There were seven or eight participants in each group, which met 13–14 times over a period of 8 months. This study is based on semistructured interviews about the participants’ situation just before entering the counselling group, the counselling programme itself, and their situation after the end of the programme. Their situations before the programmes were described as an exhausting, chaotic prison but after the programme they could cope with their situation and plan and manage their daily life. None of the participants needed further organised counselling; engagement in the local dementia association was sufficient for them. The counselling nurses’ experience in and about caring for demented patients, their tactful authority, the closed groups and the long duration of the programme were judged to be crucial for the successful outcome of the programme.
Prevalence and clinical significance of community‐acquired penicillin‐resistant pneumococcal pneumonia in Thailand
Authors: SANGTHAWAN Patchanee , CHANTARATCHADA Sudaluck , CHANTHADISAI Nonglak , WATTANATHUM Anan
Published: May 2003

Objective:  The study aimed to evaluate the prevalence, clinical significance and outcome of community‐acquired penicillin‐resistant Streptococcus pneumoniae (PRSP) pneumonia in Thailand.

Methodology:  We conducted a prospective study in culture‐proven pneumococcal pneumonia. Pneumococci were defined as susceptible, intermediate resistance and high resistance according to the definitions of the United States National Committee for Clinical Laboratory Standards (NCCLS).

Results:  Forty‐six consecutive patients were enrolled. Of the S. pneumoniae isolates collected, 41.3% were resistant to penicillin (37% intermediate resistance and 4.3% high resistance). Resistance to other antibiotics was 13% to ceftriaxone (8.7% intermediate resistance and 4.3% high resistance), 34.8% to erythromycin, 39.1% to tetracycline, 26.1% to chloramphenicol, and 43.5% to trimethoprim ‐sulfamethoxazole. Prior antibiotic use within 3 months was significantly associated with resistance to penicillin. The overall mortality of pneumococcal pneumonia was 26.1%. Multilobar involvement and requirement for mechanical ventilation proved to be associated with mortality. However, resistance to penicillin or ceftriaxone was not associated with death.

Conclusions:  According to the US NCCLS guidelines, we found a high prevalence of drug‐resistant S. pneumoniae in Thai patients with community‐acquired pneumonia. Prior antibiotic use was significantly associated with penicillin resistance. However, the outcome was not related to in vitro penicillin susceptibility of S. pneumoniae isolated from the patients.
A marked decrease in l‐selectin expression by leucocytes in infants with Bordetella pertussis infection: leucocytosis explained?
Authors: HODGE Greg , HODGE Sandy , MARKUS Corey , LAWRENCE Andrew , HAN Ping
Published: May 2003

Objective:  Infants with Bordetella pertussis infection (whooping cough) have an unexplained lymphocytosis and leucocytosis characterized by an increase in small lymphocytes with convoluted and cleaved nuclei. To characterize these cells immunophenotyping using multiparameter flow cytometry was performed on leucocytes from a group of 11 infants aged 3–6 months with proven pertussis and from uninfected control subjects.

Methodology:  The panel of monoclonal antibodies used to elucidate leucocyte subtypes included activation, adhesion, costimulatory, memory, T‐helper (Th) 1 and Th2 markers.

Results:  Patients with pertussis showed an increase in absolute numbers of neutrophils, monocytes, T lymphocytes (both CD4 and CD8), B lymphocytes (including CD10+/CD19+ haematogones) and natural killer (NK) cells. All leucocyte subgroups showed a marked decrease in l‐selectin (CD62L) expression. The expression of other adhesion molecules CD11a, CD44 and CD54 on all leucocyte subgroups was unchanged. Expression of costimulatory molecules, CD49D and CD28 on T cells and CD80 and CD86 on monocytes, was unchanged. Lymphocyte activation markers CD69, CD25 and HLA‐DR were unchanged. There was an increase in CD45RA+/CD45RO+/CD4+ cells (activated) and CD62L–/CD45RO+/CD4+ cells (Th1‐like) but no increase in CD7–/CD4+ T cells (Th2‐like).

Conclusions:  l‐Selectin expression mediates extravasation of leucocytes into tissues and is important for homing of peripheral blood lymphocytes to lymph nodes. The significant down‐regulation of l‐selectin on leucocytes in pertussis infection may prevent leucocyte migration to areas of infection and homing and adhesion of T and B cells to peripheral lymphoid tissues. The increase in lymphocytes with Th1 phenotype may be required for effective immune response to the infective organism. These data provide a possible explanation for the absolute leucocytosis observed in this disease.
The role of dendritic cells in immune regulation and allergic airway inflammation
Authors: UPHAM John W.
Published: May 2003

Abstract:  Dendritic cells (DC) are potent antigen presenting cells that display an extraordinary capacity to present antigen to naïve T‐cells and initiate primary immune responses. In the context of the lung and upper airway it is clear that DC play a key role in the regulation of adaptive immune responses to inhaled antigen. DC are particularly sensitive to signals derived from microbes, allergens and the airway tissue microenvironment. By the nature of the signals they provide at the time of antigen presentation, DC can polarize naïve T‐cells into either T‐helper type 1 (Th1) or Th2 effector cells, and are increasingly recognized as having a central role in the establishment of T‐cell memory and peripheral immune tolerance. DC form a network within the upper airway and lung, and are rapidly recruited from the circulation in response to a variety of proinflammatory stimuli. Studies using animal models have highlighted the role of DC in both the initiation and maintenance of allergic airway inflammation. In early childhood, human DC are functionally immature, and this is thought to contribute to the development of allergic sensitization in those children who are genetically at risk for the development of atopy. Increased numbers of airway mucosal DC are found in both allergic rhinitis and asthma, while studies of blood‐derived DC have emphasized important differences between the function of DC from atopic and normal individuals. This article reviews recent information on the involvement of DC in allergic airway disease, and the mechanisms by which DC could be exploited as targets for therapy in asthma and allergic rhinitis.
Brain injury in children with congenital heart disease
Authors: Scallan Michael J. H.
Published: May 2003

The incidence of neurodevelopmental impairment in children with congenital heart disease is high. Its aetiology is multiple and complex. Prevention and treatment must start during the preoperative period and continue through the intra‐ and postoperative periods. Research has resulted in a clearer understanding of the relationship between congenital heart disease and the brain, and of the effects of cardiopulmonary bypass, hypothermia and circulatory arrest. This has led to modifications in management which may improve neurological outcome in the future.
Increased incidence of postoperative nausea and vomiting without additional analgesic effects when a low dose of intravenous fentanyl is combined with a caudal block
Authors: Kokinsky E. , Nilsson K. , Larsson L. E.
Published: May 2003

Background: The use of opioids is known to increase the incidence of postoperative nausea and vomiting (PONV). In spite of this, administration of low doses of an opioid during anaesthesia is common practice, even if a regional anaesthetic technique is used. This study was designed to estimate the effects of intraoperative intravenous administration of fentanyl on PONV in paediatric daycase surgery.

Methods: PONV and pain were evaluated in 29 boys during the first 24 h after daycase penile surgery. Anaesthesia was standardized. The patients were allocated to two groups. Fentanyl 1 µg·kg−1i.v. or placebo was administered in a randomized, double‐blind design. A caudal block with ropivacaine 2 mg·ml−1, 0.5 ml·kg−1was performed preoperatively and topical lidocaine gel 20 mg·ml−1was applied over the wound area immediately after surgery.

Results: The total incidence of PONV in hospital and at home during the first 24 h was 36% (5/14) when fentanyl was used, whereas no PONV was reported when placebo was given (P < 0.05). The median time to first administration of analgesics after the caudal block was approximately 6 h. It did not differ between groups. Intraoperative fentanyl did not result in any reduction in pain scores nor the incidence of pain. Fentanyl caused apnoea in one‐half of the cases and decreased the breathing rates during the first 10 min of surgery.

Conclusions: Intraoperative use of i.v. fentanyl 1 µg·kg−1combined with a regional anaesthetic block is associated with an increased incidence of PONV without any significant contribution to the postoperative pain relief.
Side‐effects of postoperative epidural analgesia in children: a randomized study comparing morphine and clonidine
Authors: Cucchiaro G. , Dagher C. , Baujard C. , Dubousset A. M. , Benhamou D.
Published: May 2003

Background: Morphine is widely used in association with local anaesthetics for postoperative epidural analgesia. There are no data on the prolonged use of clonidine for postoperative analgesia in children. The primary outcome of this randomized, double‐blind trial was to compare the incidence of side‐effects after epidural infusion of clonidine or morphine, in association with ropivacaine in children.

Methods: After institutional approval, 26 children, aged 3–12 years, who were scheduled for abdominal surgery, had an epidural catheter placed after induction of general anaesthesia. Patients were then randomized to two different groups. After an initial bolus of 2.5 mg·kg−1 0.25% ropivacaine with either 40 µg·kg−1 morphine (group M, n = 14) or 1 µg·kg−1 clonidine (group C, n = 12), an epidural infusion was started at a rate of 0.4 ml·kg−1·h−1. The patients in the M group received an infusion of 0.08% ropivacaine with 10 µg·ml−1 morphine, those in the group C an infusion of 0.08% ropivacaine with 0.6 µg·ml−1 clonidine.

Results: The two groups were similar with respect to age, sex and weight. One patient in the C group was excluded for misplacement of the epidural catheter. The incidence of vomiting and pruritus was significantly higher in the M group compared with the C group (64% and 85% versus 0%, respectively). The incidence of pain was significantly higher in the C group compared with the M group (73% versus 29%) as well as the need for rescue analgesia medications.

Conclusions: Epidural clonidine is followed by a significantly lower incidence of side‐effects. However, its analgesic effects, at least at the doses used in this study, are less potent than those of epidural morphine.
Caudal neostigmine for postoperative analgesia in paediatric surgery
Authors: MemiŞ Dilek , Turan Alparslan , Karamanlioğlu Beyhan , Kaya Gaye , Süt Necdet , Pamukçu Zafer
Published: May 2003

Background: This study was conducted to evaluate analgesia and side‐effects of caudal neostigmine coadministered with bupivacaine in paediatric surgery.

Methods: We studied children, aged 1–5 years, undergoing elective surgery (inguinal hernia and hypospadias). After standard induction of anaesthesia, caudal anaesthesia was performed. Group 1 received 0.25% bupivacaine 0.5 ml·kg−1 and Group 2 received 0.25% bupivacaine 0.5 ml·kg−1 with 1 μg·kg−1 neostigmine via the caudal route. Heart rate, mean arterial pressure, peripheral oxygen saturation were recorded before induction, after induction but before caudal anaesthesia, and then every 5 min after caudal anaesthesia. Haemodynamic, Toddler, Preschooler, Postoperative Pain Scale (TPPPS) pain score and sedation score values were recorded 30 min after extubation and at hours 2, 4, 6, 12 and 24. A pain score >3/10 resulted in administration of rectal paracetamol. The duration of postoperative analgesia was defined as the time between caudal drug injection and the first rectal paracetamol administration.

Results: There were no differences between the groups in demographic and haemodynamic date, duration of surgery and anaesthesia, time to extubation or sedation scores. The duration of postoperative pain relief did not differ between the two groups; 15.40 ± 10.97 h for group 1 vs. 15.45 ± 10.99 h for group 2 (P > 0.05). The incidence of nausea (three patients in group 2 and one patient in group 1) was not statistically significant. No other side‐effects were seen.

Conclusions: We found that a single caudal injection of 1 μg·kg−1 neostigmine mixed with bupivacaine offers no significant advantage over bupivacaine alone for postoperative pain relief in children undergoing genitourinary surgery.
Dorsal penile nerve block
Authors: Soh C. R. , Ng S. B. A. , Lim S. L.
Published: May 2003

Background: The dorsal penile nerve block (DPNB) is a common form of regional anaesthesia for circumcisions in children. The safety of this block has been questioned following several case reports of potentially serious complications.

Methods: We performed a retrospective review of all the incidents related to the conduct of this block in our institution over a period of 53 months.

Results: A total of 3909 circumcisions were performed under DPNB and nine incidents were recorded. This included two cases of bleeding from the prepuce, two urethral injuries, three haematomas and two drug errors. Two cases required further surgical intervention but all of the patients recovered with no apparent long‐term sequelae.

Conclusions: We feel that the DPNB is a safe technique for circumcisions in infants and children.
Life threatening subcutaneous emphysema following surgical repair of tracheocutaneous fistula
Authors: Mohan Virender Kumar , Kashyap Lokesh , Verma Sanjay
Published: May 2003

A 9‐year‐old male child posted for closure of tracheocutaneous fistula developed extensive subcutaneous emphysema resulting in acute respiratory distress immediately after transfer to recovery room. The clinical management, precautions and other complications of closure of tracheocutaneous fistula are discussed.
Difficult airway in a child with spinal muscular atrophy type I
Authors: Arima Hajime , Sobue Kazuya , Tanaka Sayuki , Morishima Tetsuro , Ando Hiroshi , Katsuya Hirotada
Published: May 2003

Spinal muscular atrophy (SMA) type I is a relatively common inherited neuromuscular disease of hypotonic newborns, but is not associated with craniofacial abnormalities. There is nothing in the literature about difficult intubation in patients affected by this disease. We report a case of 34‐month‐old girl with SMA type I who was scheduled for emergency endoscopic laser treatment of tracheal stenosis caused by granulations. Tracheostomy was performed at 17 months of age and before this, the orotracheal tube was changed periodically without difficulty. For this laser treatment, orotracheal intubation was required. Preoperative physical examination revealed micrognathia and class II malocclusion. Opening her mouth was not difficult. Although difficult orotracheal intubation was predictable, we attempted to intubate her trachea as usual, but could not visualize the epiglottis. We decided to proceed with retrograde intubation, one of the standard techniques employed in a child with a difficult airway, via the tracheostome. A feeding nasogastric catheter was used as a guide catheter, and our strategy was successful. In this study we report a case of difficult airway in a child with SMA type I. The relationship between SMA type I with a tracheostome and difficult airway are discussed.
Complete staged palliation of hypoplastic left heart syndrome in a child with cystic fibrosis
Authors: Stuth Eckehard A. E. , Stucke Astrid G. , Fedderly Raymond T. , Tweddell James S.
Published: May 2003

In recent years, the palliative treatment of Hypoplastic Left Heart Syndrome (HLHS) with a three‐staged surgical repair has gained widespread acceptance in North America and elsewhere and has significantly improved the life‐expectancy of these children. We report on a child in whom the diagnosis of cystic fibrosis (CF) was made shortly after the first‐stage palliation (modified Norwood procedure), and in which surgical palliation was successfully completed with second‐ (bidirectional Glenn) and third‐stage (fenestrated Fontan) procedures. During this period, the child suffered several CF‐related complications, i.e. repeated respiratory failure, meconium ileus and coagulation abnormalities, which required adjustment of the anaesthesia, surgical and intensive care management. Considering the trend to perform surgical corrections of major cardiac defects in the early neonatal period, before concomitant genetic diseases are discovered, paediatric cardiac anaesthesiologists, surgeons and intensivists may be confronted with more cases of open heart surgery in infants with CF in the future.
A combined stage 1 and 2 repair for hypoplastic left heart syndrome: anaesthetic considerations
Authors: Müller Matthias , Akintürk Hakan , Schindler Ehrenfried , Bräu Michael , Scholz Stefan , Valeske Klaus , Michel‐Behnke Ina , Thul Josef , Schranz Dietmar , Hempelmann Gunter
Published: May 2003

Therapy of hypoplastic left heart syndrome (HLHS) consists of the staged Norwood procedure or cardiac transplantation. Stenting the ductus arteriosus and subsequent banding of the pulmonary arteries allows the combination of neoaortic reconstruction with the establishment of a bidirectional cavopulmonary connection (combined stage 1 and 2 procedure) in a later session. We report the anaesthetic management in eight infants ranging from 107 to 195 days undergoing a combined stage 1 and 2 procedure. Nonselective pulmonary vasodilators and nitric oxide were needed in all cases to improve oxygen saturation in the postbypass period. Phosphodiesterase inhibitors and epinephrine were required in all patients for inotropic support during and after weaning off cardiopulmonary bypass. The procedure was successful in seven patients. One patient died intraoperatively because of right heart failure. The physiological changes of this new surgical strategy for palliation of HLHS offers a challenge for the anaesthetist primarily in the early postbypass period.
A randomized trial of caudal block with bupivacaine 4 mg·kg−1 (1.8 ml·kg−1) plus morphine (150 μg·kg−1) vs general anaesthesia with fentanyl for cardiac surgery
Authors: Rojas‐Pérez Eduardo , Castillo‐Zamora Carlos , Nava‐Ocampo Alejandro A.
Published: May 2003

Background: Regional anaesthesia has been used effectively in paediatric patients undergoing cardiac surgery and is thought to be safe.

Methods: Thirty patients ASA physical status II–III undergoing scheduled palliative or corrective cardiac surgery, receiving premedication with midazolam and anaesthetic induction with sevoflurane, fentanyl and pancuronium were randomly allocated to two groups. In group 1, patients received bupivacaine 0.22% 4 mg·kg−1 (1.8 ml·kg−1) and morphine 150 μg·kg−1 by the caudal route. After a 20‐min period for the block to take effect, sevoflurane 0.5–1.0% and fentanyl 5 μg·kg−1 were administered for maintenance of anaesthesia. In group 2, the anaesthetic technique was the same as in group 1, without a caudal block and fentanyl 25 μg·kg−1 was administered at the moment of surgical incision.

Results: Cardiovascular and haemodynamic responses of patients receiving caudal block showed minor variations during the 20‐min period between caudal and general anaesthesia. Fentanyl requirements during surgery were lower (P = 0.001) in patients with caudal block than patients with general anaesthesia. Extubation time was shorter (P = 0.034) in the caudal group. Two patients in the general anaesthesia group and one in the caudal group died because of postoperative complications.

Conclusions: Caudal block with bupivacaine 0.22% 4 mg·kg−1 (1.8 ml·kg−1) and morphine 150 μg·kg−1 was safe and effective for paediatric patients undergoing cardiac surgery. However, patients might have a better outcome with a reduction of morphine dosage and administration of a muscle relaxant of shorter duration of action than pancuronium.
The dynostatic algorithm accurately calculates alveolar pressure on‐line during ventilator treatment in children
Authors: Sondergaard Soren , Kárason Sigurbergur , Hanson Angela , Nilsson Krister , Wiklund Jan , Lundin Stefan , Stenqvist Ola
Published: May 2003

Background: Monitoring of respiratory mechanics during ventilator treatment in paediatric intensive care is currently based on pressure and flow measurements in the ventilator or at the Y‐piece. The characteristics of the tracheal tube will modify the pressures affecting the airways and alveoli in an unpredictable manner. The dynostatic algorithm (DSA), based on a one‐compartment lung model, calculates the alveolar pressure during on‐going ventilation. The DSA is based on accurate measurement of tracheal pressure. The purpose of this study was to test the validity of the DSA in a paediatric lung model and to apply the concept in an observational clinical study in children.

Methods: We validated the DSA in a paediatric lung model with linear, nonlinear pressure flow and frequency‐dependent characteristics by comparing calculated dynostatic (alveolar) pressures with directly measured alveolar pressures in the model and proximal plateau pressure with maximum alveolar pressure. Sixty combinations of ventilation modes, positive end expiratory pressures, inspiratory : expiratory ratios, volumes and frequencies were studied. A 0.25‐mm fibreoptic pressure transducer in the tube lumen was used in combination with volume and flow from ventilator signals.

Clinical measurements were performed in eight patients during anaesthesia and postoperative ventilator treatment.

Results: In the lung model we found a correlation coefficient between calculated and measured alveolar pressure of 0.93–0.99 with root mean square median values of 1 cm H2O. Distal plateau pressure agreed well with maximum alveolar pressure. In the clinical situation, the algorithm provided a breath‐by‐breath display of the volume‐dependent lung compliance and the temporal course of alveolar pressure during uninterrupted ventilation.

Conclusions: Fibreoptic measurement of tracheal pressure in combination with the dynostatic calculation of alveolar pressure provides an on‐line monitoring of the effects of ventilatory mode in terms of volume‐dependent compliance, tracheal peak pressure and true positive end expiratory pressure.
Flumazenil is innocuous in a paroxysmal supraventricular tachycardia and radiofrequency ablation: a paediatric case report and review of the literature
Authors: Weinbroum Avi A. , Glick Aharon , Belhassen Bernard
Published: May 2003

The efficacy and safety of flumazenil in reversing midazolam‐induced paradoxical reaction in a child suffering from paroxysmal supraventricular tachycardia (PSVT) and undergoing radiofrequency ablation procedure has not been described before. We report a boy who had suffered for years from poorly controlled PSVT because of noncompliance to medications and was being sedated by midazolam and morphine (4 mg each) and prepared for radiofrequency ablation when he began attempting to speak, writhing and flailing his arms, for which physical restraint was required. We also review the current knowledge on the subject.

Two doses of flumazenil 0.05 mg i.v. swiftly halted the untoward episode. The child opened his eyes and was calm, coherent and able to answer simple questions. All haemodynamic and respiratory parameters remained stable throughout this event, except for a temporary increase in heart rate (from 68 to 83 b·min−1). The aberrant behaviour did not resume when he was allowed to fall asleep during the ablation of a concealed left lateral accessory pathway. After that procedure, he awoke calm and pain free with no recollection of the aggressive episode. He was kept for 24 h in an intermediate cardiac care unit and was then discharged home.

This apparent first report on the efficacious use of flumazenil for the reversal of a paradoxical reaction to midazolam during an electrophysiological study suggests that it neither induces abnormal heart rate nor interferes with the electrophysiological study or the ablation procedure.
Bispectral Index in a 3‐year old undergoing deep hypothermia and circulatory arrest
Authors: Zabala Luis , Ahmed Mohammed Iqbal , Denman William T.
Published: May 2003

We report a 3‐year‐old girl who presented with Scimitar syndrome and underwent hypothermic circulatory arrest for correction of anomalous pulmonary veins and an atrial septal defect. In this case the Bispectral Index (BIS) correlated significantly with the gradual onset of hypothermia and circulatory arrest. However, BIS remained low during the rewarming phase of cardiopulmonary bypass, in spite of adequate pump flows and stable haemodynamics. We postulate that this significant lag in BIS during the rewarming phase of deep hypothermic circulatory arrest may represent neuronal bewilderment or perhaps stunning, and differs from previous studies that show significant increase in BIS during rewarming from mild hypothermia.
Increased respiratory symptoms following surgery in children exposed to environmental tobacco smoke
Authors: Drongowski Robert A , Lee Donald , Reynolds Paul I , Malviya Shobha , Harmon Carroll M , Geiger James , Lelli Joseph L , Coran Arnold G
Published: May 2003

Objective: The aim of this study was to determine if children exposed to environmental tobacco smoke (ETS) via parental smoking (ETS+) developed more respiratory symptoms resulting in longer recovery times following surgical outpatient procedures compared with children of nonsmoking parents (ETS−).

Methods: One hundred and forty six children (4.9 ± 3 years) undergoing inguinal hernia repair were prospectively studied. Parental smoking behaviour was determined by survey and urine analysis. Seven respiratory symptoms were evaluated during induction and emergence from anaesthesia and during the recovery room (RR) stay.

Results: Fifty‐seven (39%) families admitted a smoking history while 89 (61%) denied it. This strongly correlated with the cotinine/creatinine ratio (Pearson correlation coefficient = 0.76; P = 0.01). ETS exposure was associated with an increased frequency of RR symptoms (ETS+: 56%; ETS−: 31%; P = 0.007).

Conclusions: In children undergoing general anaesthesia for inguinal hernia repair, ETS exposure was associated with an increased frequency of respiratory symptoms during emergence from anaesthesia and during postoperative recovery.
Dominant species maintain ecosystem function with non‐random species loss
Authors: Smith Melinda D. , Knapp Alan K.
Published: May 2003

Loss of species caused by widespread stressors, such as drought and fragmentation, is likely to be non‐random depending on species abundance in the community. We experimentally reduced the number of rare and uncommon plant species while independently reducing only the abundance of dominant grass species in intact, native grassland. This allowed us to simulate a non‐random pattern of species loss, based on species abundances, from communities shaped by natural ecological interactions and characterized by uneven species abundance distributions. Over two growing seasons, total above‐ground net primary productivity (ANPP) declined with reductions in abundance of the dominant species but was unaffected by a threefold decline in richness of less common species. In contrast, productivity of the remaining rare and uncommon species decreased with declining richness, in part due to loss of complementary interactions among these species. However, increased production of the dominant grasses offset the negative effects of species loss. We conclude that the dominant species, as controllers of ecosystem function, can provide short‐term resistance to reductions in ecosystem function when species loss is nonrandom. However, the concurrent loss of complementary interactions among rare and uncommon species, the most diverse component of communities, may contribute to additional species loss and portends erosion of ecosystem function in the long term.
Variation in the risk of being wounded: an overlooked factor in studies of invertebrate immune function?
Authors: Plaistow S. J. , Outreman Y. , Moret Y. , Rigaud T.
Published: May 2003

In invertebrates, wounding can trigger an immune response, and will often expose organisms to parasites and pathogens. Here we show that in the amphipod Gammarus pulex, wounding abundance is negatively correlated with PhenolOxidase activity (a major component of the invertebrate immune response), and that the occurrence and abundance of wounding is extremely high and varies significantly between five natural populations. In some populations the prevalence and abundance of wounds also varied between sexes. Given that, using and maintaining an efficient immune system is costly, we suggest that the frequency of wounding may be an important selective pressure influencing an organism's optimal investment in immune defences.
Conspicuous extra‐floral nectaries are inducible in Vicia faba
Authors: Mondor Edward B. , Addicott John F.
Published: May 2003

Mutualistic interactions are dynamic associations that vary depending on the costs and benefits to each of the interacting parties. Phenotypic plasticity in mutualistic interactions allows organisms to produce rewards to attract mutualists when the benefits of their presence outweigh the costs of producing the rewards. In ant–plant defensive mutualisms, defences are indirect as plants produce extra‐floral nectaries (EFN) to attract predatory ants to deter herbivores. Here we demonstrate that in broad bean, Vicia faba, the overall number of EFNs on a plant increases dramatically following leaf damage. In two damage treatments, removal of: (1) one‐third of one leaf in a single leaf pair or (2) one‐third of both halves of a single leaf pair, resulted in a 59 and 106% increase in the number of EFNs on the plants, respectively, over 1 week. We suggest that the increased production of visually conspicuous EFNs is an adaptive inducible response, to attract predatory arthropods when risk of herbivory increases.
Covert infections as a mechanism for long‐term persistence of baculoviruses
Authors: Burden John P. , Nixon Clare P. , Hodgkinson Alison E. , Possee Robert D. , Sait Steven M. , King Linda A. , Hails Rosemary S.
Published: May 2003

The prevalence of pathogens in wild populations has often been estimated by the appearance of overt symptoms in the host, and this is typically used as the sole gauge of the impact of the pathogen on host dynamics. However, the development of molecular methods has increased the sensitivity with which we can detect asymptomatic infections. Baculoviruses are insect pathogens that, like many microparasites, are usually only found when their hosts reach outbreak densities, when a disease epizootic occurs. Conventional wisdom is that the long‐term persistence of baculoviruses relies on their survival in the external environment in the form of occlusion bodies. These are proteinaceous matrices in which the virus particles are embedded, and which provide a degree of protection from UV irradiation. However, Mamestra brassicae has also been shown to harbour a persistent, non‐lethal baculovirus infection (M. brassicae nucleopolyhedrovirus) in laboratory culture, which may represent another putative persistence mechanism. Here, we present evidence that such covert infections are also present and frequent in natural populations of the moth. The persistent infections were triggered into the lethal overt state by exposure to another baculovirus, and two closely related but different baculoviruses were subsequently identified as persistent infections within the populations sampled. These results have broad‐ranging implications for our understanding of host pathogen interactions in the field, in the use of pathogens as biocontrol agents, and in the evolution of virulence.
Interactions among mycorrhizae, atmospheric CO2 and soil N impact plant community composition
Authors: Johnson Nancy Collins , Wolf Julie , Koch George W.
Published: May 2003

We examined plant community responses to interactions between arbuscular mycorrhizal (AM) fungi and availability of atmospheric CO2 and soil N. Communities of 14 plant species were grown in mesocosms containing living or killed AM fungal inoculum, ambient or elevated atmospheric CO2 and low or enriched soil N. After one growing season, significantly different plant communities existed in the different treatments. Plant species richness was lowest in +N mesocosms and highest in +AM + CO2 mesocosms. At ambient CO2, AM fungi reduced richness but at elevated CO2 they increased it. This was caused by changes in mortality rates of several C3 forbs and may suggest that CO2 enrichment ameliorates the carbon cost of some AM symbioses. Soil moisture was higher in +CO2 mesocosms but +AM counteracted this effect. These results suggest that AM symbioses may be important mediators of plant community responses to anthropogenic CO2 and N enrichment.
Alternative male life‐history tactics as potential vehicles for speeding introgression of farm salmon traits into wild populations
Authors: Garant Dany , Fleming Ian A. , Einum Sigurd , Bernatchez Louis
Published: May 2003

Releases of cultured organisms, such as farm Atlantic salmon (Salmo salar L.), threaten native biodiversity and the integrity of natural communities. Salmon escaping from sea farms, however, have relatively poor reproductive success, suggesting that the rate of spread of domesticated traits may be reduced. We now compare the relative reproductive success of males that mature precociously in freshwater (parr) and find that those of farm origin have higher breeding and fertilization success than wild and hybrid individuals. Specifically, hybrid parr had 57% and wild parr 25% the success of farm parr. Early maturing males could thus be important vehicles promoting introgression of domesticated and/or non‐native traits into wild populations and ultimately have long‐term impact on the genetic integrity of native populations.
Effects of altered resource consumption rates by one consumer species on a competitor
Authors: Abrams Peter A.
Published: May 2003

Non‐mechanistic models of competition suggest that harming one of two competing species will increase the population density of the other. These models also suggest that any change in a fitness component of one competitor will make the densities of the two competitors change in opposite directions. However, models of competition that incorporate resource dynamics show that neither conclusion holds generally. Reducing the consumption abilities of one competitor may decrease the population size of the other by decreasing resource overexploitation by the first and thereby increasing its density. It is also possible for decreased consumption abilities of one species to increase the population densities of both species, when the increased density of the focal species is offset by its decreased ability to consume the main resources of its competitor. Finally, decreases in consumption may have the effects predicted by phenomenological models; a decrease in the focal species and an increase in its competitor. Unstable systems may exhibit more complicated patterns of changes in densities with changes in consumption rates. These counterintuitive effects depend on the presence of overexploitation of biotic resources, about which little is known. More generally, there have been few theoretical or empirical studies examining the indirect effects of changes in consumption rates of a focal species in a food web; these are termed ‘trait‐initiated indirect effects’. A better understanding of the potential consequences of altered consumption rates will be important for understanding biotic shifts in communities undergoing environmental change, and in using simple community modules to understand larger food webs.