bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulating potential in development of a direct developing echinoid, Peronella japonica
Authors: Kitazawa Chisato , Amemiya Shonan
Published: March 2003

The regulating potential along the animal–vegetal axis of a direct developing echinoid, Peronella japonica, was investigated using LiCl. Animal caps isolated from 16‐cell stage P. japonica embryos developed to permanent blastulae with an amniotic cavity. Treatment of animal caps with LiCl induced them to vegetalize with differentiation of the endoderm and subsequently develop into pluteus‐like larvae. The larvae derived from the LiCl‐treated animal caps were able to metamorphose and establish an adult body plan. A considerable fraction of whole embryos treated with LiCl exogastrulated and/or evaginated an amniotic cavity. The timing of the sensitivity to LiCl‐mediated induction of evagination of the amniotic cavity was earlier than that for exogastrulation. Peronella japonica embryos became sensitive to LiCl induction of exogastrulation later than embryos of indirect developers. Some larvae with evaginated archenteron and/or evaginated amniotic cavity had metamorphic potential. These results suggest that LiCl can induce both vegetalization and evagination of invaginating structures. The present study is the first to show the potential of the presumptive ectoderm region to regulate the establishment of the adult body plan without any influence from other blastomeres, revealing that the regulating potential of sea urchin embryos is much larger than previously thought.
Fibroblast growth factor‐induced gene expression and cartilage pattern formation in chick limb bud recombinants
Authors: Akiba Eiji , Yonei‐Tamura Sayuri , Yajima Hiroshi , Omi Minoru , Tanaka Mikiko , Sato‐Maeda Mika , Tamura Koji , Ide Hiroyuki
Published: March 2003

To clarify the roles of fibroblast growth factors (FGF) in limb cartilage pattern formation, the effects of various FGF on recombinant limbs that were composed of dissociated and reaggregated mesoderm and ectodermal jackets were examined. Fibroblast growth factor‐soaked beads were inserted just under the apical ectodermal ridge (AER) of recombinant limbs and the recombinant limbs were grafted and allowed to develop. Control recombinant limbs without FGF beads formed one or two cartilage elements. Recombinants with FGF‐4 beads formed up to five cartilage elements, which were aligned along the anteroposterior (AP) axis. Each cartilage element showed digit‐like segmentation. In contrast, recombinants with FGF‐2 beads showed formation of multiple thick and unsegmented cartilage rods, which elongated inside and outside the AP plane from the distal end of the recombinants. Recombinants with FGF‐8 beads formed a truncated cartilage pattern and recombinants with FGF‐10 beads formed a cartilage pattern similar to that of the control recombinants. The expression of the Fgf‐8, Msx‐1 and Hoxa‐13 genes in the developing recombinant limbs were examined. FGF‐4 induced extension of the length of the Fgf‐8‐positive epidermis, or AER, along the AP axis 5 days after grafting, at which time the digits are specified. FGF‐2 induced expansion of the Msx‐1‐positive area, first in the proximal direction and then along the dorsoventral axis. The functions of these FGF in recombinant and normal limb patterning are discussed in this paper.
Multiple personalities: Synaptic target cells as introverts and extroverts
Authors: Ritzenthaler Sarah , Chiba Akira
Published: March 2003

The intricate process of wiring a neuronetwork requires a high degree of accuracy in the communication between pre‐ and post‐synaptic cells. While presynaptic cells have been widely recognized for their dynamic role in synaptic matchmaking, post‐synaptic cells have historically been overlooked as passive targets. Recent studies in the Drosophila embryonic neuromuscular system provide compelling evidence that post‐synaptic cells participate actively in the synaptogenic process. Endocytosis allows them to quickly modify the array of molecular cues they provide on their surfaces and the extension of dynamic filopodia allows post‐synaptic cells to engage in direct long‐distance communication. By making use of familiar cellular mechanisms such as endocytosis and filopodia formation, post‐synaptic cells may be able to communicate more effectively with potential synaptic partners.
Synthesis and release of activin and noggin by cultured human amniotic epithelial cells
Authors: Koyano Satoru , Fukui Akimasa , Uchida Saiko , Yamada Kazuto , Asashima Makoto , Sakuragawa Norio
Published: March 2003

Recent studies suggest that extra‐embryonic tissues may be essential sources of early organizing signals for the mouse embryo. In vitro studies of human amniotic epithelial cells (HAEC) have shown that the amnion can produce various biologically active substances. In this study, the synthesis and release of activin A and noggin, and the activin signaling pathway, was investigated in HAEC. Conditioned medium from cultured HAEC contained activin A which was functionally active in Xenopus laevis animal cap assays. Immunohistochemistry, western blotting and reverse transcription–polymerase chain reaction confirmed that HAEC also synthesize and release noggin. Noggin transcripts were induced by the addition of recombinant activin A, and activin A was inhibited by activin antibody except in the presence of cycloheximide (CHX). These data demonstrate that noggin mRNA expression is induced directly by activin A without new protein synthesis, indicating that noggin is a primary response gene. The results suggest that there is an activin signaling pathway in HAEC, and that the human amnion might therefore be involved in neural formation during early development.
Shoot growth and tree architecture of saplings of the major canopy dominants in a warm‐temperate rainforest
Authors: Takyu Masaaki
Published: March 2003

Sapling density, shoot growth, and sapling architecture were studied in five major canopy dominants both under closed canopy and gaps in a warm‐temperate rainforest. The five species showed wide variations in distribution, shoot growth, and sapling architecture. Distylium racemosum and Quercus acuta had significantly higher sapling densities under closed canopy than in gaps. Castanopsis sieboldii and Machilus thunbergii had significantly higher sapling densities in gaps than under closed canopy. Quercus salicina showed no significant difference in sapling density between the two habitats. Under closed canopy, C. sieboldii and M. thunbergii had wider crowns than the other species. Distylium racemosum had the greatest number of terminal shoots among the species. Quercus acuta had a branchless small crown. Quercus salicina showed intermediate values in crown width, depth and the number of terminal shoots among the species. Distylium racemosum showed the greatest height‐growth rate among the species under the closed canopy, but was the slowest in gaps. Castanopsis sieboldii and M. thunbergii showed the greatest height‐growth rates among the species in gaps. Quercus salicina showed the slowest height‐growth rates both under closed canopy and gaps. All of the five species showed low mortality under closed canopy. For the major canopy dominants: (i) sapling architecture may not be an important factor in determining mortality but it may be important for height‐growth rate; and (ii) sprouting helps saplings to survive until gap formation and facilitates rapid growth in the gaps.
Ski slope vegetation at Snoqualmie Pass, Washington State, USA, and a comparison with ski slope vegetation in temperate coniferous forest zones
Authors: TITUS JONATHAN H. , TSUYUZAKI SHIRO
Published: March 2003

Ski slope vegetation at Snoqualmie Pass in Washington State, USA, was surveyed in order to identify community types and to compare it with vegetation development patterns in Japan. Ski slopes in Japan, most of which were constructed after 1960, underwent heavy land recontouring, while those at Snoqualmie Pass were constructed before 1950 with less modification. Three points apply to Japanese ski slope vegetation and differentiate these slopes from those at Snoqualmie Pass: (i) grasslands of introduced species are widespread and persistent; (ii) unvegetated patches are uncommon; and (iii) wetland vegetation has developed. These differences are mainly derived from the intensity of human impact, history of the slope and its scale: namely, ski slopes in Washington are older and larger than those in Japan. Ski slope vegetation in Washington was primarily differentiated by a soil moisture gradient. The large size of Washington ski slopes permitted the inclusion and development of wetland habitats, whereas most ski slopes in Japan are constructed on ridges and do not contain wetlands. Most introduced species in Japan are eliminated soon after seeding. In contrast, the long‐term management of ski slopes decreased soil erosion and/or unvegetated patches in Washington and created relatively permanent grasslands composed of introduced species. Tsuga heterophylla and Abies amabilis were found established on the ski slopes in Washington, whereas in Japan the pioneer tree species are shade‐intolerant broadleaved species. These differences may be a result of the different disturbance histories of ski slopes in the two countries. In addition, along with the conifers, early successional forbs such as Anaphalis margaritacea and Epilobium angustifolium are well established on Washington ski slopes. Results show that disturbances created by ski slope development greatly affect the vegetation, even on older, less heavily impacted ski slopes.
Role of male dispersal in the evolution of female altruistic behavior in viscous populations
Authors: Kawata Masakado
Published: March 2003

A computer simulation was conducted to examine the effect of differential dispersal of sexes on the evolution of altruism in viscous populations. First, a basic model, which was regarded as a purely viscous population model, was constructed. The model was assumed to be the same as the simulation model of Wilson et al. (1992), except that it assumed sexual reproduction and that only females show altruistic behavior toward females. For the basic model, altruism could not evolve when b/N ≤ c, where b is the benefit of the altruism to the recipient, c is the cost to the altruist, and N is the number of interacting neighbors. The male dispersal model I assumed that females disperse to nine neighboring sites including the natal site, but males disperse to eight sites farther than females do. For this model, altruistic alleles could evolve when b/N was equal to c or b/N was slightly smaller than c only when the male dispersal distance was slightly larger than those of females. The male dispersal model II assumed that the male dispersal distance follows a normal probability distribution. The Vole model was based on actual data of the gray‐sided vole, Clethironomys rufocanus bedfordiae, whose frequency distribution of dispersal distance was similar to a normal distribution. For these models, altruism could evolve under the condition that b/N was slightly smaller than c when the dispersal distances of males were larger than those of females. The results indicate that the differential dispersal of sexes, in which females are philopatric and males disperse farther than females, can somewhat increase the probability of spreading altruistic alleles in viscous populations.
Pattern of land mosaics affecting butterfly assemblage at Mt Ikoma, Osaka, Japan
Authors: Natuhara Yosihiro , Imai Chobei , Takahashi Mitsuko
Published: March 2003

We studied the effects of habitat mosaics on butterfly assemblage on multiple spatial scales: landscape, landscape element, local habitat, and microhabitat, based on the transect counts conducted along a 3.84 km route. The transect route, including 21 local habitats, passed through two distinct areas: 1.65 km of a secondary deciduous Quercus forest and the grove of a shrine in Hiraoka, and 2.19 km of a mosaic of secondary deciduous Quercus forest, grassland, and farmland in Narukawa. The diversity of the landscape elements and species richness were higher in Narukawa than in Hiraoka; the landscape mosaic enhanced the species richness in Narukawa. However, the diversity indices and specialist species (univoltine tree feeder) were decreased in this mosaic landscape. The species richness at local habitats was also increased by the mosaic of microhabitats, such as the herbaceous layer, glade, and mantle in the local habitats, whereas it was decreased by an abundant shrub layer. The ratios of species richness to abundance in the local habitats were lower than expected based on random sampling from the total of Hiraoka and Narukawa. This means that local assemblages were non‐random samples from an assemblage on the landscape or regional scale, and were made up by the process of habitat selection of butterfly species in the assemblages on the landscape or regional scale. For conservation of butterfly assemblages, we recommend that woodlands should be kept without fragmentation, but with glades or small grasslands, and with clearance of the shrub layer along the path.
Does fruiting phenology vary with fruit syndrome? An investigation on animal‐dispersed tree species in an evergreen forest in south‐western Cameroon
Authors: Mitani Masazumi
Published: March 2003

Fruit syndrome found in zoochorous plants is regarded as a result of hypothetical coevolution with a seed disperser/predator. Fruiting phenology was compared among two representative syndromes, such as bird–monkey syndrome (BM) and ruminant–rodent–elephant syndrome (RRE), plus the gravity dispersal species for comparison, in south‐western Cameroon in order to examine which biotic or abiotic factors educed syndrome variation. The individual size of selected plants (> 1.6 m in height) was recorded in a 16.95‐ha area for recruitment estimation and their fruiting behaviour was checked for 9 months from June 1985 to February 1986. The BM species, a suggested successful group, fruited in a less synchronous manner within species and had fruiting peaks just before and during the rainy season. The RRE species, a suggested failing group, showed greater variation within syndrome in fruiting timing, duration and synchronization. Results obtained supported no clear phenological response to corresponding vertebrates except for the case of Sacoglottis gabonensis in the RRE. The reason for concealing potential responses is probably a result of conflicting requirements for seed dispersal and offspring survival. Periodical fruiting of the BM is likely to reflect ecological constraint, such as water stress on seedlings, caused from syndrome‐specific morphological limitation. In this case, the animals have indirect effects on fruiting phenology through selecting syndrome‐specific fruit morphology. The greater variation of the RRE suggests a broad spectrum of dispersal tactics from faithful zoochory to alternatives, with a trade off between agent restriction and seed size and another trade off between parental investment and seed‐predation risk.
Effects of nutrient loadings from catchments on Asajino mire, a small coastal ombrotrophic mire in northernmost Japan
Authors: Haraguchi Akira , Uemura Shigeru , Yabe Kazuo
Published: March 2003

The relationship between water chemistry and vegetation was studied in a coastal ombrotrophic mire in northern Hokkaido, Japan. The distributions of Sphagnum and Phragmites communities were separated clearly by the pH and ion concentration of the peat surface‐pore water. The drainage ditches along the road across the center of the mire had a high pH and ion concentration, as did the peat water in the western part of the mire. It was found that fields used for livestock farming on a hill to the west of the mire leached materials into the mire through drainage ditches, surface runoff, and probably also through ground water, and thus influenced the water chemistry of the mire. Management of the water, including that in the catchment of the mire, should be introduced before biological buffering capacity against excess nutrient loading caused by human activity is exceeded and the mire loses its ombrotrophic status.
Estimation of the canopy‐gap size using two photographs taken at different heights
Authors: Yamamoto Kazukiyo
Published: March 2003

A new, convenient method to estimate canopy‐gap size using a camera is proposed. Canopy‐gap size was estimated from two images taken with a vertically mounted, digital camera at high and low points (Ph and Pl) beneath a canopy gap. The actual (AOBS) and estimated (AΔ1.0) canopy‐gap sizes were highly correlated (R2 > 0.93) for 16 canopy gaps in the Cryptomeria japonica D. Don. plantations, and the relationship between AΔ1.0 and AOBS was expressed as AΔ1.0 = 1.16AOBS. Thus, the method overestimated actual canopy‐gap size by an average of 16%.
Influence of slope aspect on Mediterranean woody formations: Comparison of a semiarid and an arid site in Israel
Authors: Sternberg Marcelo , Shoshany Maxim
Published: March 2003

This study investigates the effects of slope aspect on plant community characteristics such as plant cover, species composition and above‐ground biomass production in Mediterranean trees and shrubs in two climatological regions. Two experimental sites were selected in a climatic gradient that runs from the foothills of the Judean Hills to the northern Negev desert in Israel. In each site, 16 quadrats of 10 m × 10 m (eight south‐facing and eight north‐facing slopes) were established and the vegetation was recorded. Dominant tree and shrub species were measured using allometric parameters of area and volume, and representative branches were cut and weighed. Species studied wereQuercus calliprinos,Phillyrea latifolia,Pistacia lentiscus,Cistus creticus,Coridothymus capitatus, andSarcopoterium spinosum. The results showed that slope aspect had significant effects on the composition, structure and density of the plant communities developing in both sites. Vegetation structure within a site changed significantly in the short distance separating the north and south‐facing slopes, and that pattern remained generally constant when comparing the two sites along the rainfall gradient. The data collected here provides new insight into the slope aspect effects on biomass allocation of different woody life forms of eastern Mediterranean plant communities.
Reconstruction of local vegetation in AD 915 at an oligotrophic mire in northern Japan from pollen, present‐day vegetation and tephra data
Authors: Yonebayashi Chuh
Published: March 2003

The use of data for present‐day vegetation, modern and pretephra pollen have, together, allowed reconstruction of the spatial pattern of the vegetation of an oligotrophic mire, Shimo‐kenashi Mire, in AD 915. The modern pollen data were compared with the surrounding vegetation, showing that pollen of Ericaceae, Rosaceae (excluding Sanguisorba), Sphagnum and Liliaceae, together with trees and shrubs, which form scrub or thicket, indicate the limits of the mires. Shimo‐kenashi Mire was narrower in AD 915 and had more islands and peninsulas of scrub. Subsequently, the mire margin has advanced and the scrub islands and peninsulas have disappeared at some sites. The fact that the mire is spreading implies that conditions are wetter since AD 915, caused by changes in local hydrology. This history of vegetation at the site will contribute to the conservation and management of the mire as trends in vegetational change provide the basic information for conservation strategy.
Early post‐fire succession in California chaparral: Changes in diversity, density, cover and biomass
Authors: Guo Qinfeng
Published: March 2003

For four consecutive years, following the fires in November 1993, temporal variations in species richness, cover and biomass of component plant groups in early post‐fire chaparral succession were monitored on different aspects at the Stunt Ranch Santa Monica Mountains Reserve, southern California. Plant groups were categorized based on growth form, life form, ability to fix nitrogen, geographic origin and regeneration strategies. North‐facing slopes exhibited higher species richness, higher species turnover rate over time and faster vegetation recovery in terms of biomass accumulation and return to pre‐fire species composition. This was probably due to higher species richness and biomass of nitrogen‐fixing species found on north‐facing slopes in comparison to south‐facing slopes. On both north‐ and south‐facing slopes, annuals had the highest species turnover rate, followed by herbaceous perennials and shrubs. In the first four post‐fire years, annual species were the largest floristic group, but herbaceous perennials and shrubs were the major contributors to community biomass. Nitrogen‐fixing species and exotics contributed significantly to early post‐fire community structure. Although the general trends in post‐fire succession are clear in terms of temporal changes in the relative proportions of different plant groups, environmental variation and the nature of plant life histories of component species, especially dominant species, could alter such trends significantly.
Long‐distance dispersal of tree seeds by wind
Authors: Horn Henry S. , Nathan R.A.N. , Kaplan Sarah R.
Published: March 2003

Some mechanisms that promote long‐distance dispersal of tree seeds by wind are explored. Winged seeds must be lifted above the canopy by updrafts to have a chance of further dispersal in high velocity horizontal winds aloft or in landscape‐scale convection cells. Shear‐induced turbulent eddies of a scale up to one‐third of canopy height provide a lifting mechanism. Preliminary data suggest that all seeds of a given species may be viable candidates for uplift and long‐distance dispersal, despite the evidence that slow‐falling seeds are dispersed farther under any given wind conditions. Turbulence is argued more often and more extensively to advance long‐distance dispersal than to retard it. Seeds may take advantage of ‘Bernoulli sailing’ to move with faster than average winds. Elasticity of branches and trees may play a role in regulating the release of seeds into unusually favorable winds. Dispersal is at least biphasic, and the study of long‐distance dispersal calls for mixed models and mixed methods of gathering data.
Seasonal subsidy stabilizes food web dynamics: Balance in a heterogeneous landscape
Authors: Takimoto Gaku , Iwata Tomoya , Murakami Masashi
Published: March 2003

Resource subsidies from external habitats can substantially affect the food web dynamics of local habitats. In this paper, we explore a mathematical model that is tailored for a stream food web, studied by Nakano and colleagues, in which consumers, in situ prey and subsidies all show seasonal fluctuation. The model reveals that the food web dynamics are stabilized if subsidies increase in summer when in situ productivity is low. Consumer dynamics are stabilized because subsidies complement seasonal resource deficiency. In situ prey dynamics are stabilized because subsidies indirectly balance the predation pressure by consumers, with seasonal change in prey carrying capacity. In summer when prey carrying capacity is low, seasonally abundant subsidies indirectly decrease predation pressure, whereas in winter, with high prey carrying capacity, scarce subsidies increase the predation pressure. Our results suggest that temporal productivity differences between spatially linked habitats are important to promote the stability of food web dynamics in a landscape context.
Differences in nitrogen use efficiency between leaves from canopy and subcanopy trees
Authors: Tateno Ryunosuke , Kawaguchi Hideyuki
Published: March 2003

We examined the effects of increasing light availability along a vertical gradient within a forest community on the efficiency of leaf nitrogen (N) use in individual trees. The N contents of green and senescent leaves in canopy and subcanopy trees of an evergreen coniferous species, Podocarpus nagi, and an evergreen hardwood species, Neolitsea aciculata, were analyzed in a mixed forest community at Mt Mikasa, Nara City, Japan. The inverse of N concentration (NC) in senescent leaves was used as an index of N use efficiency (NUE) at the leaf‐level. The leaf‐level NUE was higher in canopy trees than in subcanopy trees in both P. nagi and N. aciculata, although soil N mineralization rates around canopy and subcanopy trees did not differ significantly. The NC in green leaves was lower in canopy trees than in subcanopy trees. The ratio of resorbed N in senescent leaves to the N content in green leaves was higher in canopy trees than in subcanopy trees. The higher leaf‐level NUE of canopy trees was partly a result of lower NC in living tissues and partly because of greater N resorption during senescence. The present study suggested that the leaf‐level NUE could be increased in response to an imbalance between soil N and light availability caused by spatial community structure.
Effects of mushroom size on the structure of a mycophagous arthropod community: Comparison between infracommunities with different types of resource utilization
Authors: YAMASHITA SATOSHI , HIJII NAOKI
Published: March 2003

The effects of the size of a patchy resource on the structure of a mycophagous arthropod community were examined by comparing numerical responses to the size of individual mushrooms between visitor and dweller communities. A total of 17 fungal genera in nine families were identified during the 13 month survey period. A total of 35 arthropod families from nine orders were recorded, with the Hypogastruridae (Collembola) forming 97% of the number of individuals in the visitor community. The response of the visitor community (i.e. number of families, number of individuals, density per mushroom size and diversity) to mushroom size varied in each survey month according to hypogastrurid density. The response of the community composition to mushroom size also varied monthly with hypogastrurid density. In the dweller community, 12 families in three orders were recorded, and one coleopteran and five dipteran families accounted for 90% of the number of individuals. Although the density of dwellers in a mushroom varied between months, the response of the community properties to mushroom size was consistent throughout the survey period. Community composition varied monthly with mushroom size. These results suggest that the size of individual mushrooms is likely to have a greater effect on the structure of dweller communities than visitor communities. Thus, the characteristics of a patchy resource may exert different impacts on the structure of different arthropod communities utilizing the same resource, but in a different manner.
Adelphocorisella Miyamoto and Yasunaga newly recorded from Australia, with the description of a new species (Heteroptera: Miridae: Mirinae)
Authors: Malipatil MB , Chérot F
Published: March 2003

Adelphocorisella australis sp. n. is described from north Queensland. This, the first representative of the genus known from Australia, is compared with the two previously described species, both from Japan.
Which triage category patients die in hospital after being admitted through emergency departments? A study in one teaching hospital
Authors: Dent Andrew , Rofe Geoff , Sansom Guy
Published: March 2003

Abstract

Objectives: To quantify the number of deaths per triage category (scale 1–5, Australian National Triage Scale) occurring after admission to hospital via an emergency department and to examine the causes of death in each category.

Setting: St Vincent's Hospital, Melbourne (Victoria, Australia) is an acute adult tertiary referral hospital.

Methods: Electronic collection of all hospital admissions and their subsequent destination for the calendar year 1997, with chart and/or postmortem review to determine the cause of death.

Results: The percentage of deaths per triage group decreased with urgency. Numerically, the largest group of all admissions and admissions followed by deaths consist of patients presenting in category 4 (semi‐urgent).

Conclusions: Triage categories may be a useful tool for prioritizing acute patients, but patients in low triage categories often have fatal illnesses. Performance measurements and workload assessments for emergency departments may need to involve category 4 patients to take account of this factor.
Slow‐release potassium overdose: Is there a role for magnesium?
Authors: Davey Michael , Kuhn Marie
Published: March 2003

Slow‐release potassium overdose is rare and often fatal. Recommended treatment is derived from that of other, more common, causes of hyperkalaemia and from the general principles of overdose management. We present a patient who survived after a massive slow‐release potassium (Slow‐K®) ingestion resulting in a peak potassium concentration of 12 mmol/L, the highest yet reported. A review of previously reported cases of potassium overdose and a summary of recommended therapies for the treatment of hyperkalaemia are presented. Laboratory and current clinical evidence support the addition of magnesium to standard therapy for potassium overdose, particularly where there is concern about increasing doses of calcium; this suggestion requires further clinical research.
Penetrating and blunt cardiac trauma: Diagnosis and management
Authors: Sava Jack , Demetriades Demetrios
Published: March 2003

Cardiac trauma is often lethal in the field, but the majority of patients may be salvaged if they survive transport. Management of penetrating injury depends on rapid diagnosis of haemopericardium and prompt surgical repair. Identification of blunt injury is a diagnostic challenge, but most patients do well with appropriate monitoring and prompt recognition of complications. A review of diagnosis and management of penetrating and blunt cardiac injury is presented with extensive references.
Successful treatment of presumed death‐adder neurotoxicity using anticholinesterases
Authors: Little Mark , Pereira Peter
Published: March 2003

We present the first reported case in Australia of anticholinesterases being used successfully in conjunction with antivenom to treat neurotoxicity following death‐adder envenomation. A 49‐year‐old man was bitten by his pet death adder. He developed significant neurotoxicity due to delayed presentation and suboptimal first aid. Following one ampoule of polyvalent antivenom which produced an allergic reaction, administration of neostigmine and atropine facilitated aeromedical evacuation without the need for mechanical ventilation. After three ampoules of monovalent death‐adder antivenom at the receiving hospital, antivenom supplies were exhausted. Further neostigmine and atropine resulted in complete resolution of paralysis, allowing discharge. Anticholinesterases may reduce the dose of antivenom required to treat death‐adder envenomation. They may also be of use in cases of allergic reactions to antivenom, and in reducing the need for endotracheal intubation.
Drug‐ and poison‐related deaths in Victoria during 1997
Authors: Bystrzycki Adam , Coleridge John
Published: March 2003

Objective: To audit deaths due to prescription or illicit drugs, alcohols or poisons (hereafter referred to as ‘drugs’) occurring in Victoria in 1997 and to examine the classes of drug causing death.

Method: Retrospective review of all deaths reported to the Victorian State Coroner in 1997 in which toxicological investigation was undertaken and drugs were determined to have caused death. Deaths due to heroin and carbon monoxide were separately audited by the Victorian Institute of Forensic Pathology and are excluded from this paper.

Results: One hundred and seventy‐three people died with an average age of 41 years. The most frequent cause of death was combined drug overdose (64 cases, 37%). Ethanol was the commonest single drug causing death (32 cases, 18%), followed by prescribed opiates (18 cases, 10%) and tricyclic antidepressants (15 cases, 9%). Four teenagers died while inhaling butane or propane. In 14 cases (8%), toxic levels of selective serotonin and noradrenaline re‐uptake inhibitor antidepressants were found in combination with drugs known to produce fatal drug interactions.

Conclusions: Drug overdose remains a common cause of death. Prescribed opiates and ethanol are most frequently associated with death, followed by the older and more dangerous antidepressant medications. The newer selective serotonin and noradrenaline re‐uptake inhibitors may not be as safe as was initially proposed.
Non‐medical technicians reduce emergency department waiting times
Authors: Grouse Andrew , Bishop Rod
Published: March 2003

Objective:

To observe the impact of trained non‐medical technicians on emergency department waiting times. The technicians were to perform minor procedures that had previously been performed by medical staff.

Methods:

A prospective cohort study with two matched groups of patients. One group comprised patients who presented to the emergency department on days when the technicians worked (working group) and the other comprised patients who presented when the technicians did not work (control group). The waiting times for patients in each group were compared.

Results:

The median waiting time was 10 min shorter in the working group than the control group (P < 0.0001). This reduction was confined to triage categories 3 and 4. The number of patients who left without being seen was reduced from 8.2% in the control group to 5.3% in the working group (P < 0.00001).

Conclusion:

When added to the normal staff complement, non‐medical technicians reduce patient waiting times in the emergency department.
Spontaneous pneumomediastinum, pneumothorax and ecstasy abuse
Authors: Mazur Stefan , Hitchcock Thomas
Published: March 2003

A case report is presented of a patient with bilateral pneumothoraces and spontaneous pneumomediastinum associated with ecstasy use. Pneumothorax and spontaneous pneumomediastinum should be considered in an ecstasy user who complains of chest pain, neck pain or shortness of breath.
Are methods used to estimate weight in children accurate?
Authors: Black Karen , Barnett Peter , Wolfe Rory , Young Simon
Published: March 2003

Objective: The exact weight of a child undergoing resuscitation is usually not known. Several methods to estimate a child’s weight have been proposed. We evaluated six of these methods to determine their accuracy and clinical usefulness across a range of weights and ages.

Method: Children attending a tertiary paediatric emergency department on 30 non‐consecutive days were weighed, a length or height was obtained and an estimation of body habitus (slim, average or heavy) made by a single investigator, Karen Black (KB). All children less than 145 cm were also measured using the Broselow tape. Six methods of weight estimation were employed and the calculated weight compared to the true weight. The weight estimation methods evaluated were the advanced paediatric life support (APLS) method, Broselow tape, devised weight estimation method (DWEM), Oakley table, Traub–Johnson and the Traub–Kichen methods.

Results: Four hundred and ninety‐five children were included in the study. Children were evenly distributed among the weight groups of less than 10 kg, 10–25 kg, 25–40 kg and over 40 kg. The methods with the best overall performance were the devised weight estimation method and Broselow tape although the latter has a length limitation of 145 cm. The other methods performed well in the middle two weight groups but poorly outside these groups.

Conclusions: The most accurate methods of weight estimation in children are the Broselow tape and the devised weight estimation method . We recommend the use of either of these methods in emergency situations where direct weighing is not possible.
High‐pressure water injection injury: Emergency presentation and management
Authors: Subramaniam Rathan M , Clearwater Gary M
Published: March 2003

Presentations of high‐pressure water blaster injuries to the emergency department are varied. Though these injuries are sometimes described as a ‘benign variant’ of high‐pressure injection injuries, external appearances can be deceptive. These injuries can produce an unexpected pattern of severe internal injury and infectious complications. Such injuries are surgical emergencies and must be evaluated quickly and thoroughly in the emergency department. We review the current literature of these injuries and present the first reported case involving a forearm injury.
Is a negative dipstick urinalysis good enough to exclude urinary tract infection in paediatric emergency department patients?
Authors: Doley Andrew , Nelligan Melissa
Published: March 2003

Background: Urinary tract infection is a common cause of serious bacterial infection in young children. The non‐specific presentation has implications for misdiagnosis and the potential for long‐term complications.

Aims: To determine if a negative dipstick urinalysis is adequate to exclude urinary tract infection in children aged 0–10 years. Data was subdivided into two age groups: 0–2 years and 2–10 years.

Methods: Retrospective case note review over an 8‐month period. Cases included required a printed urinalysis recorded from the Clinitek 50 (Bayer) machine and a printed microscopy and culture result. We defined a negative urinalysis as being negative for all of blood, protein, leucocytes and nitrites. A total of 375 cases were included for statistical calculation.

Results: Three hundred and seventy‐five cases gave a prevalence of 10.7% with a sensitivity of 92.5%, specificity of 39.4% and a negative predictive value of 97.8%. In the 0–2‐year‐old group, we demonstrated a prevalence of 15%, a sensitivity of 87.5%, specificity of 39.7% and a negative predictive value of 94.7%. This compares to the older group (2–10 years) with a prevalence of 7.0%, a sensitivity of 100%, specificity of 39.7% and a negative predictive value of 100%.

Conclusions: Prevalence of urinary tract infection varied with age with a higher prevalence in the 0–2 years age group. The lower negative predictive value and the higher clinical importance in this age group means that dipstick urinalysis is inadequate to exclude urinary tract infection. Conversely, we believe that children in the 2–10 years age group can adequately have urinary tract infection excluded with a negative dipstick urinalysis.
Brachial plexus injury occurring during breast surgery
Authors: Ng Kkc , Cheung Kl
Published: March 2003

A case of brachial plexus injury occurring during axillary dissection as part of breast conservative surgery for breast cancer is reported. The mechanisms, diagnosis and management of such injury are discussed. Proper positioning of the patient is the key to preventing brachial plexus injury.
Leaking thoraco‐abdominal aortic aneurysm in Marfan syndrome
Authors: Alfred Cc Wong , Albert Cw Ting , Stephen Wk Cheng
Published: March 2003

Marfan syndrome is a congenital disorder of the connective tissue involving the ocular, skeletal and cardiovascular systems. Cardiovascular complications account mainly for the reduced life expectancy of patients with Marfan syndrome. Thoracic aortic aneurysms usually occur as a result of proximal aortic dissection but aneurysms of the descending aorta are infrequent. We report on a patient with rupture of an extensive thoraco‐abdominal aortic aneurysm (Crawford type III) with a concomitant chronic thoracic aortic dissection (Stanford type A), treated successfully with aneurysmectomy and visceral artery reconstruction. Subsequent surgical intervention for the concomitant chronic thoracic aortic dissection was also performed. The importance of life‐long surveillance of the cardiovascular system is highlighted.
Technique for safe placement of reusable trocars during endoscopic extraperitoneal inguinal hernioplasty
Authors: Lau Hung , Lee Francis , Patil Nivritti Gajanan , Yuen Wai‐Key
Published: March 2003

Endoscopic extraperitoneal inguinal hernioplasty has become an established technique for the repair of inguinal hernias. To reduce the cost of the procedure, reusable metallic trocars are substituted for disposable trocar ports. However, the use of metallic trocars is often associated with pericannula air leak and uncontrolled sliding movements. The insertion of the primary subumbilical trocar by open dissection technique has been widely accepted but percutaneous placement of secondary trocars with sharp obturators, even under direct endoscopic vision, is still potentially hazardous in the confined extraperitoneal space. We have, therefore, modified our method of placement of secondary trocars with finger dissection and railroad techniques. Making the trocar snug with a purse‐string suture over the fascial opening can substantially reduce peri‐cannula air leak, diminish the sliding movement of the cannula and facilitate closure of the wound. To avoid the risk of visceral and major vascular injuries, all endoscopic instruments are blunt‐tipped. Open dissection combined with finger dissection and railroad techniques enables the safe placement of trocars for endoscopic extraperitoneal inguinal hernioplasty.

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NON‐SURGICAL TREATMENT OF CHRONIC SUBDURAL HAEMATOMA—ROLE OF STEROID
Authors: Sun David T.F. , Boet Ronald , Poon W.S.
Published: March 2003

Aim:

Response to surgery has been very satisfactory and this is generally considered the treatment of choice for chronic subdural haematoma (CSDH). In this study, however, we would like to identify the group of patients who can be managed with steroid (dexamethasone) successfully without surgery.

Method:

From a series of 121 cases of CSDH being managed in our hospital during the period from January 1998 to December 1999, we studied the 24 patients who are intended to be treated initially with steroid alone. Clinical features and outcomes were compared with the other 97 patients.

Results:

There were 70 men and 51 women, 37–91 years old being treated in our hospital with CSDH. Twenty‐four of them were initially planned to be treated with steroid alone (varied from 4 to 21 days). Of these, five (20%) presented with focal weakness while seven patients (30%) were confused on admission. The maximum thickness of the CSDH varied from 5 mm to 30 mm. Only one of them (4%) required drainage later, which was done 1.5 months after the presentation. Two of them (8%) were severely disabled while all the others (92%) had favourable outcomes. No mortality was noted in this group of patients. No significant complication from steroid was seen. Fourteen other patients were not given steroid and not planned for surgery initially. One of them died (7%) while two of them (14%) required later drainage and the other one defaulted follow up. Eighty‐four patients underwent surgical drainage. Thirteen of them were not given steroid and two of them (15%) required redrainage. The remaining 71 patients underwent surgical drainage in addition to steroid administration. The width of the subdural haematoma varied from 10 mm to 40 mm. Four of them (6%) required repeated drainage. Two mortality cases with sepsis and liver failure respectively were noted in this group and one other death was due to intracerebral haemorrhage 1 month after the procedure (mortality = 4%). Two (3%) were severely disabled. All the others (93%) had favourable outcome.

Conclusion:

We believe that, with careful case selection, CSDH can be safely managed conservatively with steroids initially. Surgical drainage can be reserved for those showing features of rapid increase in intracranial pressure or comatose patients. This regimen will help to avoid unnecessary surgical risks particularly for those elderly and unfit patients.
Prediction of common bile duct stones and cholangitis in acute biliary pancreatitis
Authors: Wong Simon Kin‐Hung , Lam Yuk‐Hoi , McKay Colin John , Lee Danny Wai‐Hung , Sung Joseph Jao‐Yiu , Chung Sydney Sheung‐Chee
Published: March 2003

Objective:

To define factors in predicting common bile duct (CBD) stones and cholangitis in patients with acute biliary pancreatitis.

Method:

Retrospective analysis of patients with acute biliary pancreatitis who received early (< 72 h) endoscopic retrograde cholangiopancreatography (ERCP). Data on their clinical presentation, severity of attacks, liver function on admission, ERCP findings and bile culture results were analysed.

Results:

Sixty‐four patients admitted with acute biliary pancreatitis were referred for early ERCP. Common bile duct stones were found in 33 patients (52%). Only five (8%) patients presented with symptoms suggestive of coexisting acute cholangitis (fever, abdominal pain and jaundice). Bile cultures were positive in 12 of 18 specimens (67%), and nine of these (75%) were associated with choledocholithiasis. Variables were entered into a logistic regression analysis and a high bilirubin level on admission was the only significant factor in predicting ductal stones.

Conclusion:

In the locality of Hong Kong the incidence of choledocholithiasis is high in acute biliary pancreatitis and only a high bilirubin level can predict CBD stones. Although many patients have infected bile, overt cholangitis is relatively uncommon.

Chinese Abstract

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Retained intra‐aortic balloon pump catheter causing acute ischaemic limb: Report of two cases
Authors: Tse Chad Cheuk‐Wa , Li Wing‐Hong , Tang Philip Lap‐Fai , Hwang James Shu‐Tak
Published: March 2003

Intra‐aortic balloon pump (IABP) catheter is used widely in the management of left heart failure. Its complications are well described; however, retained IABP catheter is an extremely rare but serious complication, which is seldom described. Fewer than 20 cases have been reported. Two cases of entrapment of IABP catheter which resulted in acute limb ischaemia requiring surgical intervention for its removal are reported. Its prevention and management are also discussed.
Perception of native grassland in southeastern Australia
Authors: Williams Kathryn , Cary John
Published: March 2003

SummaryNative grasslands are considered to be one of Australia’s most threatened ecosystems, yet relatively little is known about human preferences and attitudes that contribute to continued degradation of these landscapes. In a study conducted in southeastern Australia, landholders were asked to assess the agricultural, ecological and aesthetic value of native grasslands and other rural landscapes depicted in colour photographs. The results confirm low preference for treeless landscapes. Landholders’ preferences for native grassland on their own property appeared most closely related to the perceived agricultural and aesthetic value of the grassland scene. This paper discusses the implication of these findings for programmes seeking to protect native grasslands on private properties.

Key wordsenvironmental attitudes, native grasslands, perception.