bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in diapause attributes between two clinal forms distinguished by male‐to‐male aggression in a subsocial spider mite, Schizotetranychus miscanthi Saito
Authors: Saito Yutaka , Sakagami Takane , Sahara Ken
Published: March 2003

The nest‐weaving spider mite Schizotetranychus miscanthi Saito showed a cline in male‐to‐male aggression intensity with minimum winter temperature. The altered kin structure in spring nests, which might be caused by winter harshness, was hypothesized to be a key factor responsible for the cline in male‐to‐male aggression. In Japan, we found two forms (high‐ and low‐aggression forms) that showed different clinal trends with similar regression slopes and different intercepts. The former is characteristic of local populations from milder climates, whereas the latter occurs in harsher climates. We hypothesized that the intensity of female diapause, which may determine whether males are produced during late winter, was one of the factors separating these two clinal forms. In the four populations studied, short day length during the developmental period (egg to adult emergence) induced diapause in females. Diapause intensity varied greatly among populations, and particularly between the high‐aggression and low‐aggression forms. These data, together with data on winter harshness between the localities, led us to believe that female diapause is one of the factors affecting relatedness between interacting males in nests and can explain why the two forms of S. miscanthi have different clinal trends in male aggression in Japan.
Effects of worker manipulation on the sex ratio of a Japanese ant species,Myrmecina nipponica
Authors: Kikuchi Tomonori , Yoshioka Riho , Azuma Noriko
Published: March 2003

In order to test the effects of colony size and nutritional condition on the survivorship and sex ratio of ants,Myrmecina nipponicacolonies were housed in a laboratory in colony sizes of 10 or 30 individuals and fed either daily or weekly. Under all conditions, most of the larvae successfully grew into adults, which suggests that survivorship was not significantly affected by either colony size or nutritional condition. However, the number of new queens was significantly higher in colonies that were fed daily. These results indicate that workers do not control the proportion of diploid and haploid broods by eliminating some larvae and that nutritional condition exerts a significant effect on sex ratio.
Competition between Eucalyptus victrix seedlings and grass species
Authors: FLORENTINE SINGARAYER K. , FOX JOHN E. D.
Published: March 2003

Competition in a natural system may be interspecific or intraspecific. In semiarid ecosystems, competition for resources between established neighboring grass species and newly recruited seedlings is very high. To examine the effects of grass species density, growing space and time of establishment on Eucalyptus victrix seedlings (interspecific competition), and the effect of density and growing space within E. victrix (intraspecific competition) we conducted an experiment under controlled conditions. We tested four hypotheses (i) E. victrix seedling growth is not affected by grass density; (ii) there is no difference in E. victrix survival and growth between early and later grass establishment; (iii) interspecific competition is not more intense than intraspecific competition in E. victrix; and (iv) growth of E. victrix seedlings is not dependent on available growing space. In a monoculture of E. victrix, seedling mortality was higher (10%) in large pots. In mixed culture pots, where E. victrix seedlings and grass seedlings were planted on the same day, E. victrix seedlings survived for up to 4 weeks, but started to die after week five in the smallest pots. However, mortalities occurred in pots of all sizes when grass was established before E. victrix seedlings. Results also indicated that the resources necessary for the growth of individual E. victrix seedlings were more limiting under conditions of increased density of neighboring grass species rather than intraspecific competition. In particular, photosynthetic area of E. victrix seedlings was drastically reduced in mixed cultures. Although density, pot size and time of planting had impacts on E. victrix seedlings, the patterns of these impacts were variable.
Relationship between bird‐unit size and territory quality in three species of fairy‐wrens (Malurus spp.) with overlapping territories
Authors: CHAN KEN , AUGUSTEYN JOHN D.
Published: March 2003

The relationship between unit size and territory quality and size was examined in variegated, superb and red‐backed fairy‐wrens in an area in which the birds’ territories overlapped extensively. Variegated fairy‐wrens had the least number of paired birds and the largest mean unit size. More than half of the superb and red‐backed fairy‐wrens occurred in pairs. Territory size did not differ between the species. A positive correlation between unit size and territory size was found only in the variegated fairy‐wren. Stepwise regression analyses with backward elimination on 10 habitat variables showed that unit size was associated with different territory‐quality measures in the three fairy‐wren species. It is suggested that species that are more inclined to form pairs or small groups during the breeding season are also more sensitive to ecological factors and prefer not to form large groups in a resource‐limited environment.
Initial verification of the resistance management strategy for Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in Australia
Authors: Herron GA , Cook DF
Published: March 2003

Shortly after the initial detection of western flower thrips (WFT), Frankiniella

occidentalis (Pergande), in Australia during 1993 a resistance management strategy based on the alternation of chemical groups was implemented. This study aimed to verify this strategy by field testing α‐cypermethrin against WFT with and without chemical alternation. Up to 114 times α‐cypermethrin resistance (at LC50) was detected and resistance increased with and without chemical alternation; however, chemical alternation did significantly reduce numbers of thrips compared with a nonalternation strategy. Resistance has the potential to undermine the sustainable use of those chemicals to which there is no current detectable resistance. Consequently, chemicals with a high frequency and level of resistance against WFT need to be identified through monitoring and quickly eliminated from WFT chemical control recommendations.
Initiation of thrombolytic therapy for patients with acute myocardial infarction by emergency physicians: The Hong Kong experience
Authors: Ming Tang Ho , Lung Lau Fei , Kwong Chan Wai
Published: March 2003

Abstract

Objectives: To compare door‐to‐needle time and complications for eligible acute myocardial infarction patients receiving thrombolytic therapy in the emergency department and in the coronary care unit.

Methods: A prospective study was performed involving all patients with acute myocardial infarction who received thrombolytic therapy either in the emergency department or the coronary care unit during the period January 1995 to March 1996. Patients’ time interval between registration in ED and receiving thrombolytic therapy (door‐to‐needle time) was the main audit parameter. Other emergency department information collected included inappropriate administration of thrombolytic therapy and the occurrence and management of complications of thrombolytic therapy.

Results: In the United Christian Hospital, Hong Kong, 148 patients with acute myocardial infarction received thrombolysis. Sixty‐eight cases (group A) received thrombolysis in the emergency department and 80 cases underwent thrombolysis in the coronary care unit. The 80 cases in the coronary care unit included 47 cases (group B) whose diagnosis of acute myocardial infarction and eligibility for thrombolysis were established in the emergency department, and 33 cases (group C) in which there were difficulties in diagnosis or exclusion of contraindications for thrombolysis. The mean door‐to‐needle times were 31.3 min in group A (95% CI, 27.6–35.1), 54 min in group B (95% CI, 47.8–60.2) and 171.8 min in group C (95% CI, 121.8–211.8). Inappropriate use of thrombolysis in the emergency department occurred in 2.9% of all cases. The most common complication of thrombolysis in the emergency department was hypotension (4.4%). All cases were successfully managed in the emergency department. There was one case of anaphylaxis during streptokinase infusion that required resuscitation in the emergency department. There were no deaths of patients receiving thrombolysis in the emergency department.

Conclusion The initial experience of a regional hospital in Hong Kong supports the view that initiation of thrombolytic therapy in the emergency department can achieve a more favourable door‐to‐needle time without compromising the care of acute myocardial infarction patients.
Isolated pulmonary oedema associated with SCUBA diving
Authors: Grindlay Joanne , Mitchell Simon
Published: March 2003

Pulmonary oedema may be a presenting feature of the classical diving illnesses decompression illness and barotrauma, but it may also present as an isolated phenomenon. Possible causes include: salt water aspiration syndrome or near drowning (sometimes associated with faulty apparatus); and cold, immersion and exercise‐induced pulmonary oedema. The pathophysiology may involve peripheral vasoconstriction; changes in preload, afterload and circulating fluid volume; and pulmonary capillary fragility. A case that presented to Auckland Hospital is discussed, together with a review of the literature. In this case, treatment with continuous positive airway pressure ventilation proved highly effective. Guidelines for the use of continuous positive airway pressure ventilation in diving‐related accidents are presented.
Urinalysis and the plain abdominal radiograph in the diagnosis of ureteric colic
Authors: Shield Andrew C , Chu Kevin , Brown Anthony FT
Published: March 2003

Objectives: 1. To investigate the diagnostic accuracy of urinalysis and the plain abdominal radiograph in predicting positive intravenous pyelography for patients with a history and examination suggestive of ureteric colic. 2. To examine the disposition of patients presenting to the emergency department with ureteric colic.

Methods: A retrospective cohort study set in a tertiary referral hospital emergency department over a 12‐month period was conducted. Three hundred and eighteen patients who presented with a provisional diagnosis of ureteric colic and had intravenous pyelography were identified from radiology department logs and emergency department discharge International Classification of Disease‐9 codes.

Results: Three hundred and eighteen patients were identified. Sixty‐nine per cent had positive intravenous pyelography. Sensitivity and specificity of: urinalysis were 93% and 41%; abdominal X‐ray, 57% and 83%; and urinalysis plus abdominal X‐ray, 99% and 36%, respectively. Seventy‐seven per cent were admitted to the emergency department observation ward. Twenty‐seven per cent were subsequently admitted under the hospital’s urology service.

Conclusions: Sex, haematuria and the presence of a calculus on abdominal X‐ray were all significant predictors of positive intravenous pyelography. Haematuria was sensitive but not specific for positive intravenous pyelography. The addition of the abdominal X‐ray marginally improves the diagnostic accuracy.
Status of emergency department ultrasound
Authors: Fulde Gordian
Published: March 2003

Objective: To determine present attitudes to and usage of ultrasound in Australasian emergency medicine.

Methods: A questionnaire was devised, field tested and sent, with Australasian College for Emergency Medicine permission, for anonymous completion by the director of emergency medicine training of each emergency department in Australia and New Zealand accredited for advanced training.

Results: The overall response rate was 84% (66/79). The data were tabulated and cross‐tabulated comparing major trauma centres, base hospitals, urban hospitals and teaching hospitals. In hours, X‐ray department ultrasound was readily available, but bedside ultrasound was much less available both in and out of hours. There were marked variations in opinion as to whether bedside ultrasound was essential in clinical conditions such as trauma, abdominal or kidney pain. Computed tomography was always preferred to ultrasound. While there was little teaching of either the theoretical or practical aspects of ultrasound to emergency medicine trainees, 75% of respondents believed that ultrasound should not be undertaken only by full‐time ultrasonographers.

Conclusions: The survey clearly demonstrated that while bedside or urgent ultrasound is not generally readily available, especially out of hours, the modality is considered to be important by the majority of respondents, and does not require full‐time radiographers. It is clear that formal teaching of ultrasound to trainees is infrequent.
Why do people still die from brown‐snake bites?
Authors: White Julian
Published: March 2003

Brown snakes are the leading cause of snakebites and snakebite fatalities in Australia and the incidence may be rising. Most fatalities are the result of early events after the bite, often a general or cardiac collapse. Lack of appropriate first aid is a common finding. It is probable that an early thrombotic effect of venom procoagulants, prior to defibrination, is responsible for the cardiac collapse in most of these cases. CSL brown‐snake antivenom, while not perfect, is usually effective if given in sufficient quantity, but cannot reverse established vital‐organ damage. Increased public education about the danger of snakebite and correct first aid may reduce the death toll, and improved professional continuing education on snakebite is advisable but, ultimately, some brown‐snake bite deaths are probably inevitable, despite optimum medical care.
Tiger‐snake antivenom for suspected small‐eyed snake envenomation
Authors: Ivermee Peter , Desjardines Jude , McEwan Steve
Published: March 2003

Despite its relative frequency and widespread distribution throughout eastern Australia, bites by the nocturnal eastern small‐eyed snake, Cryptophis nigrescens, have seldom been recorded. There is no standard laboratory test or proven antidote for its venom, which is capable of causing life‐threatening myolysis in humans. A 39‐year‐old man presenting to hospital with acute abdominal and limb muscle pains, was noted to have a pair of puncture wounds on his leg. No venom was detected in the urine with the Commonwealth Serum Laboratories’ Venom Detection Kit. The only blood abnormality was a grossly elevated creatine kinase at 48 000 IU/L. A presumptive diagnosis of Cryptophis nigrescens envenomation was made and the patient treated with tiger‐snake antivenom (3000 U). Creatine kinase levels started to fall almost immediately and the patient made a full recovery. We believe this is the first time tiger‐snake antivenom has been used specifically for suspected Cryptophis nigrescens envenomation.
Ipecac for slow‐release potassium poisoning: Pariah or phoenix?
Authors: Geluk Michael , Braitberg George
Published: March 2003

The ingestion of a large amount of slow‐release potassium tablets presents the clinician with the problem of how best to decontaminate the gastrointestinal tract of such a patient. Oral potassium preparations are not adsorbed by charcoal and therefore an alternative must be used. The choice is between gastric emptying via emesis or surgery and whole‐bowel irrigation. At present, the scientific literature does not answer adequately the question of which one offers the best risk–benefit profile. In recent years, the use of ipecac in the emergency department has been discouraged. We present a case of a large ingestion of Slow K tablets (Novartis Pharmaceuticals, North Ryde, NSW, Australia) and discussion of the role of ipecac in the decontamination of similar cases. The question is asked whether ipecac should be considered as the initial method of gastric emptying in this specific circumstance before resorting to surgery or whole‐bowel irrigation.
Treatment of cyanide poisoning in Australasia
Authors: Braitberg George , Vanderpyl Marjory Mj
Published: March 2003

There is controversy about the most effective agent for cyanide poisoning. While dicobalt edetate has been recommended in Australia, hydroxocobalamin has been preferred in Europe. There are no comparative trials of these agents on which to base recommendations. However, a considerable volume of animal work and uncontrolled trials in humans suggest that hydroxocobalamin is safer and at least as effective. Thiosulphate appears to enhance the effect of hydroxocobalamin. The authors recommend that for patients with cyanide poisoning from smoke inhalation, significant self‐poisoning with cyanide or where there is strong clinical suspicion that cyanide poisoning is present, hydroxocobalamin should be given in a dose of 5–15 g over 30 min, or faster if necessary, accompanied by sodium thiosulphate 12.5 g over 10–20 min.
Ketamine sedation for children in the emergency department
Authors: Priestley Stephen J , Taylor James , McAdam Catherine M , Francis Peter
Published: March 2003

Objective:

To introduce a protocol for dissociative sedation using ketamine for children requiring painful procedures within the emergency department.

Method:

A medical literature search was performed along with a review of existing ketamine‐use protocols in emergency departments from Australia and the United States. Our hospital anaesthetic department and our emergency department nursing staff were closely involved in protocol design. A series of nursing education sessions were held prior to the drug being used within the emergency department. Twenty‐eight children aged 1.5–12 years were administered ketamine sedation prior to undergoing a painful procedure. Ketamine was administered either i.m. (dose 3–4 mg/kg) or i.v. (dose 1.00–2.75 mg/kg) depending on physician preference. Midazolam (dose 0.02 mg/kg) and atropine (dose 0.02 mg/kg) were given as adjuncts in the majority of cases.

Results:

Onset of sedation was rapid (range 1–7 min) for both routes and provided excellent procedural conditions. Discharge time averaged 103 min (range 67–180 min) from time of drug administration. Side‐effects included vomiting, rash, diplopia, salivation and one case of a distressing emergence reaction. On telephone follow up 1–3 days after the sedation, no delayed adverse events were reported.

Conclusion:

Ketamine is a safe and effective sedative agent for use in children requiring immobilization to enable performance of a painful procedure. It is important to involve both anaesthetic staff and emergency department nursing staff in sedation protocol development to ensure a smooth introduction. We present a protocol for ketamine use in children undergoing painful procedures within the emergency department. See Commentary, page 7.
Asystolic cardiac arrest in Melbourne, Australia
Authors: Meyer Alastair DMcR , Bernard Stephen , Smith Karen L , McNeil John J , Cameron Peter A
Published: March 2003

Objective:

To study the outcome of victims of out‐of‐hospital cardiac arrest presenting to the Metropolitan Ambulance Service in asystole, in Melbourne, Australia.

Methods:

A retrospective case‐note review of all patients presenting to the Metropolitan Ambulance Service in asystole for 1997 was performed. Metropolitan Ambulance Service case notes and hospital records were examined to determine the presenting rhythm and the patients’ outcome.

Results:

In a 12‐month period, 778 patients met the entry criteria. Age mean was 67 years, 36% female, 64% male. Metropolitan Ambulance Service response time to scene time was a mean of 9.76 min. Resuscitation was commenced on 37% of patients. There was one survivor (0.12%).

Conclusion:

Adult victims of out‐of‐hospital cardiac arrest presenting as asystole should not receive treatment. See Commentary, page 145.
Gender issues in youth suicidal behaviour
Authors: Beautrais Annette L
Published: March 2003

There are gender differences in youth suicidal behaviour that are evident in childhood and persist throughout adolescence and young adulthood. In Western countries, young females are twice as likely as males to report suicidal ideation and suicide attempt behaviour. However, despite the fact that females make more suicide attempts, males are three‐ to fourfold more likely to die by suicide than females. This paper reviews the epidemiological evidence for gender differences in suicidal ideation, attempted suicide and completed suicide among young people and explores possible reasons for the observed differences. These reasons include differences in methods, intent, ascertainment, the cultural acceptability of suicide, psychopathology (including substance abuse, mood disorder, externalizing behaviours and propensity to violence), and psychosocial differences between males and females. While it is often suggested that gender differences in youth suicidal behaviour may be explained solely or predominantly by method choice, careful examination suggests that the issues are much more complex. In fact, females may enjoy more protection from suicide than males in a number of areas. See Commentary, page 8.
The use of rapid sequence intubation by ambulance paramedics for patients with severe head injury
Authors: Bernard Stephen , Smith Karen , Foster Shane , Hogan Phillip , Patrick Ian
Published: March 2003

Objective: To determine the effects of rapid sequence intubation in patients with severe head injury performed by paramedics on a helicopter emergency medical service.

Methods: The patient care records for patients with severe head injury who underwent rapid sequence intubation between November 1999 and February 2002 (inclusive) were examined. Data were extracted on the demographics of the patients, as well as the physiological changes before and after rapid sequence intubation.

Results: There were 122 patients with severe head injury evaluated at the scene during the study period. Rapid sequence intubation was attempted in 110 patients and was successful in 107 (97%). Intubation was associated with improvements in systolic blood pressure, oxygen saturation and end‐tidal carbon dioxide levels, compared with baseline levels.

Conclusion: Rapid sequence intubation in patients with severe head injury may be safely undertaken by helicopter‐based ambulance paramedics and is associated with improvements in oxygenation, ventilation and blood pressure. Further studies of this skill undertaken by road‐based paramedics are warranted.
Axillofemoral bypass for limb salvage
Authors: Lau () Hung , Cheng () Stephen Wing‐Keung
Published: March 2003

Objective: To evaluate the early and long‐term outcomes of axillofemoral bypass performed at a tertiary referral vascular centre over a 17‐year period.

Methods: From 1982 to 1998, 30 patients underwent axillofemoral bypass at the University of Hong Kong Medical Centre. A retrospective analysis of all these records was undertaken. Data on demographic features and results of surgical intervention were reviewed. Early outcomes were analyzed with respect to morbidity, mortality and improvement of clinical category (according to the Reporting Standards of the Society for Vascular Surgery/North American Chapter, International Society for Cardiovascular Surgery). Long‐term outcomes were documented with respect to graft patency, patient survival and limb loss rates.

Results: Clinical success was achieved in 22 patients (73%) after operation. The postoperative morbidity and mortality rates were 30% and 20%, respectively. The primary patency of axillofemoral bypass was 62%, 51% and 45% at 1, 2 and 3 years, respectively. Limb loss rate was 23% at 3 years. The cumulative survival rate of the study population was 67%, 57% and 57% at 1, 2 and 3 years, respectively.

Conclusions: Axillofemoral bypass is a valuable limb‐salvaging surgical option for revascularization of lower limbs in high‐risk patients with aorto‐iliac occlusive disease.
Pathogenesis of neonatal necrotizing enterocolitis
Authors: Chan Siu‐Yin , Chan Kwong‐Leung
Published: March 2003

With recent advances in the medical management of premature infants, a higher proportion survive. Subsequently, necrotizing enterocolitis (NEC) has evolved in the past 30 years and is currently the most common gastrointestinal emergency in the neonatal intensive care unit. Necrotizing enterocolitis is associated with a high morbidity and mortality. Predominant suggested risk factors are prematurity, enteral feeding, infectious agents and intestinal hypoxia and ischaemic insult. Intestines of premature infants are defensively immature structurally and functionally. Recent studies on breast‐milk protection of NEC showed that oligosaccharide and glycoconjugates of the breast milk can alter bowel flora to lactobacillus so as to prevent enteropathogen growth. Prebiotics have been shown to promote bifidobacteria and subsequently prevention of NEC. Probiotic bifidobacteria supplementation also shows a similar beneficial effect. The use of prebiotics or probiotics to prevent NEC warrants further studies.
Laparoscopic resection of small bowel gastrointestinal stromal tumour in a patient with neurofibromatosis
Authors: Tang Chung‐Ngai , Chau Chun‐Han , Siu Wing‐Tai , Li Michael Ka‐Wai
Published: March 2003

Gastrointestinal stromal tumour has been reported to be associated with neurofibromatosis. We report here a patient with neurofibromatosis who presented with gastrointestinal bleeding of obscure origin. The small bowel tumour that was revealed by enteroclysis was successfully resected laparoscopically.
A PROSPECTIVE RANDOMIZED STUDY TO EVALUATE CLINICALLY AND RADIOLOGICALLY THE EFFECTS OF DRAINS ON PATIENTS AFTER THYROIDECTOMY
Authors: Li A.C.N. , Leong H.T.
Published: March 2003

Aim: To evaluate prospectively the usefulness of routine drainage of the neck following thyroid surgery and its effect on patient comfort.

Method: Consecutive patients who underwent elective thyroid surgery were randomized to receive suction drainage or no drainage of the neck at the end of the operation. Drains were removed on the first postoperative day and all patients underwent sonographic examination of the neck to determine the dimension of the remaining haematoma. Pain relating to the operation was assessed at 6 hours post operation and on Day 1 by visual analogue scale (VAS). Pain caused by drain removal was also assessed similarly. Postoperative complications and the lengths of hospital stay were also recorded.

Results: 60 patients were recruited and randomized, an equal number of patients with similar demographic characteristics were present in each group. The table below shows a summary of the results.

The mean pain score for pain caused by drain removal was 3.1 (range: 0–6). There was no difference for complication rate and the postoperative lengths of hospital stay for the two groups.

Conclusion: Routinely draining the neck for thyroid surgery not only failed to reduce the amount of postoperative haematoma and complication but also resulted in greater patient discomfort. Drains should therefore not be used routinely following thyroid surgery.
Generalization versus subspecialization in surgery*
Authors: Lau Joseph Wan‐Yee
Published: March 2003

The explosion in surgical knowledge and the widespread development of new technologies have made it difficult for individual surgeons to stay abreast of a single specialty. This has led to the need to develop expertise at a subspecialty, and then at a super‐subspecialty level. There are advantages and disadvantages of this trend of subspecialization and super‐subspecialization. Super‐subspecialization has cleaved general surgery (a subspecialty) along various planes into different super‐subspecialties. The author proposes a planned development of a network of units in close collaboration, linking together general surgical units, general surgical units with super‐subspecialty interests and super‐subspecialized units in dedicated centres. There should be well‐developed clinical guidelines to coordinate referral between these units so that better patient care can be provided.
Laparoscopic pancreatectomy: An initial experience
Authors: Tang Chung‐Ngai , Siu Wing‐Tai , Chau Chun‐Han , Ha Joe Ping‐Yiu , Li Michael Ka‐Wah
Published: March 2003

Three cases of laparoscopic pancreatectomy that were successfully performed during the period 1999–2000 are reported. Pancreatectomy is indicated for patients with cystic neoplasm and intrapancreatic pseudocyst causing repeated episodes of pancreatitis. The role of laparoscopy is no longer confined to the areas of diagnosis, staging and palliation. With refinement of the technique and available instruments, laparoscopic pancreatectomy is now not only feasible but might even be a better option in selected cases.
COX‐2 inhibitors and colorectal cancer chemoprevention
Authors: Tsu James Hok‐Leung , Ho Judy Wai‐Chu
Published: March 2003

Despite recent advances in the understanding of its molecular genetics, colorectal cancer remains one of the worldwide leading causes of cancer death. Compounds with the potential to halt or reverse the carcinogenesis process are being studied as possible chemoprotective agents. Among these agents, non‐steroidal anti‐inflammatory drugs (NSAID) have been shown to significantly reduce colorectal cancer risk. A new generation of NSAID with specific inhibition towards the isozyme cyclo‐oxygenase 2 (COX‐2) has been introduced recently to clinical use with the aim of causing fewer adverse effects. Studies using these COX‐2 inhibitors have demonstrated a significant chemopreventive effect via various mechanisms. In a short‐term randomised controlled trial, these COX‐2 inhibitors have also shown encouraging results in patients with familial adenomatous polyposis (FAP). However, further studies are necessary before routine clinical use of this class of agents can be used in the management of FAP patients and other at‐risk population groups.

Chinese Abstract

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Clinical aspects of conjunctival melanoma
Authors: Layton Christopher , Glasson William
Published: March 2003

Conjunctival melanoma is a rare but important condition encountered in ophthalmology. This paper reviews conjunctival melanoma as a clinical entity, with particular emphasis on differential diagnosis, management and prognostic factors. Relevant references were located through a comprehensive search of articles published between 1980 and early 2001 on Medline, using both the WinSpirs and PubMed platforms. The references of these articles were then checked for further articles of relevance. The condition is uncommon and its presentation variable; therefore, relevant studies were found to suffer from small numbers of subjects. This may be the cause of the confusion that still surrounds the condition and its management.
Review of ecological restoration programme on subantarctic Macquarie Island: Pest management progress and future directions
Authors: Copson Geof , Whinam Jennie
Published: March 2003

Summary The establishment of exotic species of vascular flora and vertebrate fauna on subantarctic Macquarie Island since its discovery in 1810 has resulted in major changes in the biota. A management programme aims to reduce the numbers of exotic plant and animal species and assist with the recovery of pre‐existing communities and processes. This paper reviews the integrated vertebrate pests management programme on Macquarie Island since 1974 and outlines future management considerations. As part of this programme, the responses of some native and exotic species of vascular flora and vertebrate fauna were monitored following control of European Rabbit (Oryctolagus cuniculus) numbers. Changes in the vegetation recorded over 10 years showed that approximately half of all the vascular species had benefited from rabbit grazing, including several which formed a major part of the rabbit’s diet. After rabbit control, some adversely affected plants responded rapidly to a reduction in grazing pressure while others will require an almost total cessation of grazing in order to re‐establish their former distributions. With the decrease in rabbit numbers it was also necessary to control Feral Cats (Felis catus) due to their increased predation on native burrow‐nesting birds. Feral Cat predation on introduced fauna also increased, one result of which was the eradication from the island of the introduced Weka (Gallirallus australis scotti). Reduced rabbit grazing is leading to re‐establishment of the native Tall Tussock (Poa foliosa) grassland and with it the spread of the introduced Ship Rat (Rattus rattus). This review indicates that an integrated approach to pest management, with monitoring of the responses of both target and non‐target species, is the most effective way to restore pre‐existing communities and processes.

Key words grazing pressure, introduced species, predation, recovery, vertebrate pest management.
Remnant vegetation, landholders’ values and information needs: An exploratory study in the West Australian wheatbelt
Authors: Moore Susan A. , Renton Stephen
Published: March 2003

Summary An exploratory study of landholders in the central wheatbelt of Western Australia provides a useful snapshot of values, uses, management, information sources and requirements of landholders in relation to remnant native vegetation in agricultural landscapes. Landholders valued their remnant vegetation for ecological, aesthetic, functional and community reasons. Most actively managed it for nature conservation, although almost half grazed stock in their remnants. In terms of information sources and needs, the most widely used sources were Community Landcare Coordinators, other landholders and government departments. Landholders wanted hydrological, weed control and biodiversity information, plus a suite of other information. A third of landholders were characterized as having a broad, ecosystem‐based awareness compared to the other two‐thirds who had a more limited, site‐based awareness. Each group had different information needs. These findings have clear implications for information provision to landholders.
Influence of scattered paddock trees on surface soil properties: A study of the Northern Tablelands of NSW
Authors: Wilson Brian
Published: March 2003

Summary Surface soil conditions were assessed under three tree species on a property near Armidale on the Northern Tablelands of NSW. In both a stocked and adjacent destocked paddock, five trees each of three eucalypt species: Eucalyptus melliodora, Eucalyptus blakelyi and Eucalyptus nova‐anglica, were selected. Soil samples were collected (depth 0–10 cm) along transects 20 m in length running from beneath the tree canopy progressively outwards into the open paddock. Six additional transects were also sampled outside the influence of the trees. Soil properties at a distance from the trees differed little between the stocked and destocked paddock with only a slight acidification in the stocked paddock. However, soil properties around the scattered trees showed considerable variation between stocked and destocked equivalents and most notably in a systematic pattern with distance from the trees themselves. For example, bulk density increased significantly, whereas soil pH, carbon, nitrogen and extractable phosphorus contents all decreased significantly with distance from the trees. However, stocking and camping had modified some of these soil properties. In the stocked paddock, the systematic change in nitrogen and phosphorus with distance from the trees was less clear and the degree of dispersion of the data was largest at the most heavily camped site. In this paddock, bulk density was also generally higher whereas pH, carbon and nitrogen contents were lower compared with the destocked equivalent. Extractable phosphorus content was also higher around the trees in the stocked paddock especially where camping activity was most intense. It is concluded that, although animal camping can modify their effects, scattered trees have a beneficial effect on soil properties and in this respect they have value in the grazing system from a soil conservation perspective.
A palynological reconstruction of pre‐European riparian vegetation at Wollombi, New South Wales and its application to stream bank management and revegetation
Authors: Bennett P. , Mooney S. D.
Published: March 2003

SummaryA palynological investigation was conducted on sediments from three small floodplain swamps on upper Wollombi Brook in the Hunter Valley NSW in order to reconstruct pre‐European riparian vegetation composition and community structure. Pre‐European riparian plant communities on upper Wollombi Brook were characterized by wet sclerophyll forest associations with rainforest elements (most likely close to the channel). Major changes in both the nature and extent of riparian vegetation have been associated with European settlement. The pre‐European pollen spectra assists the identification of a suite of native taxa potentially suitable for use in riparian revegetation operations, particularly in highly cleared streambank sites where protection of water quality and aquatic habitat is an important goal but where insufficient local remnants are available to indicate pre‐existing plant species. The research emphasizes the use of palaeoenvironmental evidence as a tool for contemporary environmental management.
Co‐incubation of Acanthamoeba castellanii with strains of Pseudomonas aeruginosa alters the survival of amoeba
Authors: Cengiz Am , Harmis N , Stapleton F
Published: March 2003

Enhanced survival of Acanthamoeba castellanii has previously been reported following co‐incubation with a single strain of Pseudomonas aeruginosa. The aim of this study was to evaluate the impact of different strains of P. aeruginosa on amoebae survival. Four contact lens solutions were challenged with A. castellanii for between 6 and 24 h, and survival rates of amoeba were calculated. Subsequently, A. castellanii was co‐incubated with different strains of P. aeruginosa (strain 6294, an invasive isolate; 6206, a cytotoxic isolate; and Paer 001, a null isolate). Differences in amoeba survival over time between solutions for each bacterial strain were analysed. Non‐neutralized hydrogen peroxide was the most effective system against A. castellanii at all time points (P < 0.05). Survival rates were not different between multipurpose solutions and neutralized hydrogen peroxide. Co‐incubation with P. aeruginosa altered amoeba survival, and maximum survival occurred in the presence of the invasive strain of P. aeruginosa. Enhanced amoeba survival may occur in the presence of certain strains of Gram‐negative bacteria, and with certain types of contact lens disinfection systems.
Direct costs of blindness in Australia
Authors: Wright Suzie E , Keeffe Jill E , Thies Leslye S
Published: March 2003

This study calculated the direct financial costs of blindness to the Australian government and community. Three case studies, representative of Australians with severely impaired vision, were used to calculate the annual costs associated with blindness. The costs include pensions, subsidies, concessions, equipment and services. Case 1 was a retired person with age‐related macular degeneration, case 2 a working aged person with diabetic retinopathy, and case 3 a school student with congenital vision impairment. Sensitivity analysis was used to show the possible range of costs for each case. For case 1, direct cost was $14 686 with a range from $9749 to $22 507. The cost for case 2 was $17 701 ranging from $9669 to $26 720. Costs associated with care and education of case 3 were $15 948 ranging from $5106 to $23 798. In addition to the social costs to a person who is blind, there are significant financial costs to the government and the community that will increase substantially with the ageing of the Australian population.
Association of presbyopic correction with changes in visual fields
Authors: Dimitrov Peter N , Nanjan Mukesh B , Taylor Hugh R , McCarty Cathy A
Published: March 2003

The purpose of this study was to investigate the effect of presbyopic correction on changes in visual fields caused by an alteration in outflow of aqueous humour. Visual fields were compared before and after introduction of presbyopic correction in participants of the Melbourne Visual Impairment Project. Height and slope of the ‘Hill of Vision’ were assessed by calculating median thresholds in the four sets of three eccentric points. Analysis of 101 eyes in the study group and 101 eyes in the control group shows higher decrease of the ‘Hill of Vision’ height in the group of participants who started wearing presbyopic correction, than in the group without presbyopic correction (P = 0.02). Intraocular pressure measured irrespectively of participant’s accommodative activity was not significantly different between the two groups at both time points. These data suggest that the use of presbyopic correction is associated with changes in the visual field.
Ocular parameters in the subgroups of angle closure glaucoma
Authors: Sihota R , Lakshmaiah NC , Agarwal HC , Pandey RM , Titiyal JS
Published: March 2003

Purpose: This study was conducted to compare anatomical parameters, thought to be responsible for causing angle closure glaucoma (ACG), among eyes having acute, subacute or chronic ACG.

Methods: Ninety consecutive patients diagnosed with a subgroup of ACG, and 30 age, sex and refraction matched controls, provided a total of 240 eyes for a prospective study. The refractive error, corneal diameter, keratometry, pachymetry, lens thickness and axial length were measured and the relative lens position was calculated. The data were analysed by paired t‐test,
ANOVA, signed rank test and multivariate analysis.

Results: Acute ACG eyes were mildly hyperopic. All the ACG subgroups had similarly short eyeballs and a steeper corneal curvature compared to control eyes. Acute ACG lenses were thicker than all the other groups (P < 0.001), but all ACG eyes had thicker lenses than the controls. Corneal diameters and anterior chamber depths were decreased in acute and chronic ACG eyes compared with subacute ACG and controls (P < 0.001). The uninvolved fellow eyes in each subgroup differed from affected eyes only in having more posteriorly positioned lenses.

Conclusions: There was a spectrum of anatomical variations seen in the subgroups of ACG. Acute ACG eyes expressed an extreme shift of anatomical features away from normal, especially, smaller corneal diameters, leading to a large mobile lens in an already crowded anterior segment. This predisposed them to a severe relative pupillary block, and to a form of ciliary block glaucoma. Chronic ACG eyes were less divergent from normal and therefore could have suffered a milder form of the same kind of angle closure, but over a more prolonged period. Subacute ACG eyes deviated least from controls, and therefore exhibited mild signs and spontaneous resolution. Further work is required to elucidate completely the pathophysiology that leads to ACG.
Brimonidine and postoperative pressure spikes in cataract surgery
Authors: Whitehouse Geoff
Published: March 2003

Purpose: To evaluate the efficacy of brimonidine in controlling postoperative pressure spikes following clear corneal cataract outpatient day surgery, in private practice in Australia.

Methods: A prospective randomized trial was performed on 123 patients. Brimonidine 0.2% was instilled in the eyes 15 min prior to surgery, and intraocular pressure was checked 6 hours postoperatively.

Results: Mean postoperative intraocular pressures at 6 hours were 30.33 mmHg in the treated group and 30.76 mmHg in the control group.

Conclusion: Brimonidine 0.2% instilled preoperatively offered no significant reduction in postoperative intraocular pressure spikes.
Potential acuity meter results in cataract patients
Authors: Devereux Catherine J , Rando Angelo , Wagstaff Christine M
Published: March 2003

Purpose: To determine the ability of the potential acuity meter (PAM) to predict potential visual acuity through lenticular opacities in a group of cataract patients without significant other ocular pathology.

Methods: This prospective study undertook PAM measurements on each eye of 84 subjects during preoperative hospital visits to either A Scan or Primary Care clinics. PAM results were compared to best corrected visual acuity findings obtained at least 6 weeks post‐cataract extraction.

Results: Comparison of PAM result to visual outcome showed poor correlation (rho = 0.41, P = 0.0005). Using predictive estimates, 49% of subjects’ PAM results underestimated visual outcome as determined by a difference of greater than 2 Snellen acuity lines in these results. Factors such as preoperative vision level, cataract type and pupil dilation did not significantly influence the predictive power of the PAM. Preoperative pinhole results were also correlated with visual outcome (rho = 0.42, P = 0.0006). Vison in the fellow eye of subjects with 6/9 or better was correlated to the PAM result indicating a moderate to good predictive power in ‘normal’ eyes.

Conclusions: PAM results were considered to be poor for a clinical test. The results of this study indicate that this instrument has only a limited usefulness as part of the standard preoperative examination in patients undergoing cataract extraction.
Random amplified polymorphic DNA analysis of Acinetobacter species isolated from worn contact lenses
Authors: Corrigan Karen M , Zhu Hua , Willcox Mark DP
Published: March 2003

The purpose of this study was to explore the genotypes of Acinetobacter species and to compare the genotypes and phenotypes of the Acinetobacter isolated from contact lens wearers. Nineteen strains were used in the study, 13 were isolated from patients experiencing an adverse response event, and six strains were isolated from asymptomatic contact lens wearers. Random amplified polymorphic DNA and phenotypic analyses were carried out using commercially available kits. Random amplified polymorphic DNA analysis showed a higher discrimination power compared with the phenotypic analysis. The test strains were loosely clustered into six genotypic groups with no definite relation to any clinical events. These results indicate that many genotypes of Acinetobacter can cause adverse responses, and the initial source of the microorganisms rather than their clinical sequelae may determine classification.
Achromatic impulses unmask L‐ and M‐cone adaptive mechanisms
Authors: Zele Andrew J , Vingrys Algis J
Published: March 2003

The mechanisms underlying the adaptive response for achromatic impulses seen on achromatic fields were investigated. Foveal thresholds were measured for a static probe‐impulse under two conditions of adaptation. Thresholds were obtained under gain‐clamped conditions after observers had reached steady‐state adaptation and with a probe‐flash paradigm. It was found that thresholds isolated on steady‐state fields cannot be modelled using a single mechanism. Likewise, the probe‐flash condition failed to reflect the response of a single mechanism. Both threshold functions showed distinct breaks occurring at about the same field luminance (approximately 1.0 log cd/m2). Optimum data fits required the incorporation of two mechanisms implying the existence of independent processes mediating detection. Chromatic isolation confirmed that differential adaptation had been unmasked in the long‐ and medium‐wavelength sensitive cone inputs to the achromatic channel.