bluuebunny/crossref_metadata_2025 huggingface dataset:
Transjugular liver biopsy effecting changes in clinical management
Authors: Lee David , Chitturi Shivakumar , Kench James , George Jacob , Fuller Steven , Bradstock Ken , Lin Rita , Wong Kai Ping , Young Noel
Published: June 2003

Although transjugular liver biopsies are frequently performed in patients with impaired blood coagulation, their impact on effecting changes in clinical management has not been assessed. We reviewed our experience with 43 consecutive transjugular liver biopsies performed over 3 years (1998−2000) at Westmead Hospital, Sydney, Australia. The technical success, procedural complication rates and subsequent management of these patients were ascertained from the medical case records. Forty‐two (28 men) patients were studied. The indications for liver biopsy were as follows: assessment of hepatitis/cirrhosis status (n = 21), evaluation of liver dysfunction following bone marrow transplantation (n = 19) and miscellaneous (n = 2). All liver biopsies were performed with a Cook 20‐G transjugular cutting needle device. Adequate histological samples were obtained in 42 (98%) of the 43 biopsies performed. The pre‐biopsy diagnoses were confirmed by histology in 28 cases (65%). A change in clinical diagnosis was observed in 12 (28%) patients, and there were changes to subsequent management in all 12 patients. Four patients developed procedural complications, including small neck haematomas in two patients and a self‐limiting biliary fistula in one. The only major complication was an extracapsular bleed from a hepatic laceration. This patient required emergency surgery but recovered. Transjugular liver biopsies can be effectively and safely performed in high‐risk patients with impaired coagulation. They aid accurate histological appraisal of liver dysfunction in these patients and influence clinical decision‐making.
Breast compression in mammography: How much is enough?
Authors: Poulos Ann , McLean Donald , Rickard Mary , Heard Robert
Published: June 2003

The amount of breast compression that is applied during mammography potentially influences image quality and the discomfort experienced. The aim of this study was to determine the relationship between applied compression force, breast thickness, reported discomfort and image quality. Participants were women attending routine breast screening by mammography at BreastScreen New South Wales Central and Eastern Sydney. During the mammographic procedure, an ‘extra’ craniocaudal (CC) film was taken at a reduced level of compression ranging from 10 to 30 Newtons. Breast thickness measurements were recorded for both the normal and the extra CC film. Details of discomfort experienced, cup size, menstrual status, existing breast pain and breast problems were also recorded. Radiologists were asked to compare the image quality of the normal and manipulated film. The results indicated that 24% of women did not experience a difference in thickness when the compression was reduced. This is an important new finding because the aim of breast compression is to reduce breast thickness. If breast thickness is not reduced when compression force is applied then discomfort is increased with no benefit in image quality. This has implications for mammographic practice when determining how much breast compression is sufficient. Radiologists found a decrease in contrast resolution within the fatty area of the breast between the normal and the extra CC film, confirming a decrease in image quality due to insufficient applied compression force.
Primary angiitis of the central nervous system: MRI features and clinical presentation
Authors: Singh Surendra , John Susan , Joseph Thykkoothathil Pappy , Soloman Thilak
Published: June 2003

We report the MRI features in a series of four patients with primary angiitis of the central nervous system (PACNS). Based on MRI features, clinical presentation, paraclinical investigations and laboratory tests, including cerebrospinal fluid (CSF) analysis, various differentials were considered. In two patients with MRI findings of cortical, subcortical and deep white matter lesions, lack of mass effect, focal areas of bleed and heterogeneous parenchymal, leptomeningeal or pial enhancement and a normal magnetic resonance angiography, a differential diagnosis of primary angiitis of the CNS was also considered. In all patients, an open brain biopsy was advised to establish a definitive diagnosis of PACNS. Here, we briefly discuss the MRI features, correlation with clinical presentation and paraclinical parameters for the diagnosis of this entity. We also briefly review the literature.
Survey of effective dose levels from typical paediatric CT protocols
Authors: McLean Donald , Malitz Nathan , Lewis Sarah
Published: June 2003

Concern over reported large radiation doses leading to a high cancer risk for paediatric CT patients has prompted considerable investigation in paediatric CT. The recent release of software from Germany has allowed effective doses to be calculated from CT protocol information and radiation measurement for standard paediatric patient sizes for both sexes. An initial study has been undertaken in nine radiology departments, four of which were dedicated paediatric departments, for routine chest and abdominal CT procedures. The dose calculation software is based on Monte Carlo simulation of X‐ray conditions during a CT procedure and utilized a ‘tomographic’ phantom model of a 7‐year‐old child and an 8‐week‐old baby to allow calculation of organ dose and hence effective dose. Results of the survey indicate that effective doses were higher for females than males, and higher for abdominal procedures. Slightly higher effective doses were calculated for the child compared to the baby. All centres but one recorded lower effective doses with their current protocols than if they had used recommended CT protocols found in the literature. Analysis of the survey data indicates that scan parameters are the main cause of dose variations, although the type of scanner can affect dose by a factor of 2 (when comparing different units) as well as variation in anatomy scanned in protocols. Dose reduction appears to be most closely linked with reduced mAs and increased pitch as expected. The calculation of effective dose appears to be a key factor in assessing CT protocols, particularly for paediatric patients.
Australian and New Zealand radiation oncology work practices in 2000
Authors: Veness Michael , Rikard‐Bell Glenys , Ward Jeanette
Published: June 2003

In 1996, a Faculty of Radiation Oncology (FRO) survey was sent to all practising radiation oncologists in Australia and New Zealand (ANZ) ascertaining work practices and attitudes (n = 138). In December 2000, we sent all practising ANZ radiation oncologists (n = 183) a survey in which we reproduced questions about work practice (response rate 75%). The majority of ANZ radiation oncologists were male (n = 102, 73.9%), in full time employment (n = 125, 90.6%) and subspecialized (n = 103, 74.6%). The median number of new patients seen per year was 300 (range, 10−700). However, 15% of radiation oncologists saw 350 new patients per year and 19% saw greater than 400 new patients per year. The median time allocated to work was 50 h each week. Nearly all respondents (90%) desired some amount of protected time with a median desirable of eight hours each week (range, 2−30 h, mode 8 h). The majority (n = 95, 68.8%) of respondents were members of TROG. A minority (n = 25, 18.1%) had obtained a postgraduate qualification. Many also had a clinical academic appointment (n = 60, 43.5%). Over 70 percent of respondents (n = 100, 72.5%) indicated enrolment of their patients in clinical trials. The increase in radiation oncologists with postgraduate qualifications and  commitment to clinical research, through TROG membership and patients recruited to clinical trials, is very encouraging. However, our findings demonstrate little, if any, improvement in the total weekly clinical workload of a radiation oncologist. The recent move to subspecialization has not resulted in a decrease in clinical workload. In some aspects of work practice, such as time for self‐education and research, the situation appears to be worsening.
Treatment of localized prostate cancer using a combination of high dose rate Iridium‐192 brachytherapy and external beam irradiation: Initial Australian experience
Authors: Stevens MJ , Stricker PD , Saalfeld J , Brenner PC , Kooner R , O'Neill GFA , Duval PJ , Jagavkar RS , Cross P , Martland J
Published: June 2003

Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate‐ and high‐risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate‐specific antigen progression‐free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.
Use of radiotherapy in the primary treatment of cancer in South Australia
Authors: Luke Colin , Chapman Peter , Priest Kevin , Roder David
Published: June 2003

Previous studies point to a lower use of radiotherapy by Australian cancer patients in lower socioeconomic areas and in country regions that are some distance from urban treatment centres. These were cross‐sectional studies with the potential for error from changes in place of residence. We used a cohort design to avoid such error. South Australian patients diagnosed in 1990−1994 were followed until the date of censoring of 31 December 1999 using data from the State Cancer Registry. The percentage found to have had megavoltage therapy in the first 12 months following diagnosis varied by leading primary incidence site from 44% for the prostate to 40% for female breast, 38% for lung, 17% for rectum, 3% for colon and 2% for skin (melanoma). Multivariate analysis indicated that determinants of not receiving megavoltage therapy in the first 12 months were older age, female sex, residence in a country region and country of birth. Melanoma data revealed earlier stages for women than men. If this difference by sex applies to other cancers, it might explain the lower exposure of women to radiotherapy. Fewer older patients received radiotherapy, consistent with trends observed in hospital‐based cancer‐registry data. The influence on this finding of differences in stage and comorbidity requires additional study. While earlier findings of a lower exposure of country residents to radiotherapy were confirmed, the difference was comparatively small in this study. Variations in exposure by socioeconomic status of residential area were not observed.
Accuracy of prostate radiation therapy using a fiducial point‐pair registration technique based on the computer‐assisted portal imaging quality assurance program PIPSpro
Authors: Mermershtain Wilmosh , Cohen Yoram , Krutman Yanai
Published: June 2003

The aim of this study was to assess portal imaging for quality assurance of patient positioning in external beam radiotherapy. We present a retrospective study of the variability of patient position in the treatment of 34 prostate cancer patients who were treated with whole pelvic irradiation followed by arc therapy or boost field (Series I) and 25 patients treated by ‘small’ pelvic 4‐field box technique (Series II). Weekly anteroposterior‐posteranterior (AP‐PA) and left‐lateral portal images were compared to simulation films by using a fiducial point‐pair registration technique based on the computer‐assisted portal imaging quality assurance program PIPSpro, developed specifically for the verification of treatment positioning in radiation therapy. Series I consisted of 34 patients and 194 portal films (97 AP‐PA and 97 left‐lateral). Overirradiated (OA) and underirradiated (UA) areas were computed in terms of percentage of the reference field size. For the AP‐PA portals, the average OA was 2.75% and average UA was 2.74%. For left‐lateral portals, an average OA of 2.49% and UA of 2.78% were measured. Series II consisted of 25 patients and 194 portal films (98 AP‐PA and 96 left‐lateral). The average OA was 0.88% and average UA was 0.86% in AP‐PA portals, and 1.03 and 0.82% for left‐lateral portals, respectively. The accuracy of patient positioning in irradiation of prostate cancer in our institution is in the range of 2.69% for whole pelvic fields and 1.0% for small fields. We conclude that PIPSpro is an effective and useful tool for quality assurance in radiotherapy.
Impact of oedema on implant geometry and dosimetry for temporary high dose rate brachytherapy of the prostate
Authors: Kiffer John D , Schumer Wendy A , Mantle Carmel A , McKenzie Brett J , Feigen Malcolm , Quong George G , Waterman Frank M
Published: June 2003

The optimal timing of dosimetry for permanent seed prostatic implants remains contentious given the half life of post‐implant oedema resolution. The aim of this study was to establish whether prostatic oedematous change over the duration of a temporary high dose rate (HDR) interstitial brachytherapy (BR) boost would result in significant needle displacement, and whether this change in geometry would influence dosimetry. Two CT scans, one for dosimetric purposes on the day of the implant and the second just prior to implant removal, were obtained for four patients receiving transperineal interstitial prostate brachytherapy. The relative changes in cross‐sectional dimensions of the implants were calculated by establishing the change in mean radial distance (MRD) of the needle positions from the geometric centre of the implant for each patient's pair of CT studies. The treatment plan, as calculated from the first CT scan, was used in the second set of CT images to allow a comparison of dose distribution. The percentage change in MRD over the duration of the temporary implants ranged from −1.91% to 1.95%. The maximum change in estimated volume was 3.94%. Dosimetric changes were negligible. In the four cases studied, the degree of oedematous change and consequent displacement of flexiguide needle positions was negligible and did not impact on the dosimetry. The rate and direction of oedematous change can be extremely variable but on the basis of the four cases studied and the results of a larger recent study, it might not be necessary to re‐image patients for dosimetric purposes over the duration of a fractionated HDR BT boost to the prostate where flexiguide needles are utilized. Nevertheless, further investigation with larger patient numbers is required.
Traumatic pseudoaneurysm and high flow arteriovenous fistula involving internal jugular vein and common carotid artery. Treatment with covered stent and embolization
Authors: Ramsay Duncan W , McAuliffe William
Published: June 2003

We describe the case of a 36‐year‐old man who presented following penetrating trauma to the neck. Angiography demonstrated a high‐flow arteriovenous fistula and large false aneurysm of the common carotid artery that also had contributions from branches of the external carotid artery and the thyrocervical trunk. This was treated with a combination of a covered endovascular stent placed in the common carotid artery and coil embolization of other small feeding vessels.
Occult epiphyseal bone abscess: Lessons for the unwary
Authors: Solomon Michael , Stening Michael , Macdessi Samuel , Shearman Christine , Pereira John , Hiew Chee Chung , Van der Wall Hans
Published: June 2003

Two male children presented with increasing pain in the right knee and constitutional symptoms. Biochemical markers of inflammation were elevated. Plain radiography was reported as normal and bone scintigraphy was consistent with synovitis of the right knee in the first case. The second child underwent aspiration of the knee with drainage of turbid fluid 1 week after antibiotics. Slow response to therapy led to MRI and CT scanning in the second child, revealing an epiphyseal abscess. Review of the scintigraphic studies in the first child raised the possibility of osteomyelitis of the distal right femur. Further imaging was undertaken with MRI and CT scanning confirming an epiphyseal bone abscess. Failure of diagnosis of an epiphyseal bone abscess by combined plain radiography and scintigraphy has not previously been reported and provides a number of valuable lessons.
Renal lymphangiomatosis: A rare cause of bilateral nephromegaly
Authors: Mani NBS , Sodhi KS , Singh P , Katariya S , Poddar U , Thapa BR
Published: June 2003

We report the ultrasound, excretory urography and MR findings in a young child with renal lymphangiomatosis who presented with gradually progressive bilateral flank swelling but who was otherwise asymptomatic. The typical perirenal and parapelvic cysts are visualized as hypoechoic lesions on sonography and hyperintense on T2‐weighted HASTE images. T1‐weighted image could not delineate the cysts clearly. The renal parenchyma was hyperechoic on sonography, and MRI showed reversal of the normal corticomedullary signal intensity, and confirmed the diagnosis by suggesting the non‐parenchymal origin of the cysts.
Solitary perirenal metastasis from a malignant peripheral nerve sheath tumour mimicking a primary renal tumour
Authors: Figueiras Roberto García , Ayala Max Eusebio Cachay , Figueiras Alvaro García , Escandón Manuel Alejandro Sousa , Valcárcel Javier Pérez
Published: June 2003

We present an uncommon case of a large solitary perirenal metastasis from a malignant peripheral nerve sheath tumour (MPNST) mimicking a primary renal tumour. A metastatic MPNST to the perirenal space is unusual and, in this rare location, is difficult to differentially diagnose from a primary renal tumour.
Vertebral haemangioma causing cord compression: MRI findings
Authors: Puvaneswary M , Cuganesan R , Barbarawi M , Spittaler P
Published: June 2003

A case of a thoracic intraosseous cavernous haemangioma extending into the extradural and paravertebral spaces with a dumbbell‐shaped paravertebral component is presented.
Isolated central canal rupture of spinal dermoid: Report of two cases
Authors: Garg A , Gupta V , Gaikwad S , Deol P , Mishra NK , Suri A , Kale SS
Published: June 2003

We report two cases of lumbar spinal dermoid cysts with asymptomatic rupture and migration of free fat droplets into the central canal. No fatty droplets were seen within the lumbar subarachnoid space. The presence of fat droplets within the central canal is unusual because the central canal is rudimentary in adults. We suggest that hydromyelia secondary to tumour and specific tumour morphology might facilitate the selective rupture of dermoids into the central canal. We recommend a follow up of these patients to detect any possible intracranial migration of fat droplets and resultant complications.
Oesophageal dissection: Contrast studies and CT in diagnosis and monitoring
Authors: Constantine Sarah
Published: June 2003

Oesophageal dissection with intramural haematoma formation can be difficult to diagnose. Endoscopy can be diagnostic, but imaging techniques including computed tomography and contrast swallows can both accurately demonstrate a dissection and exclude many other pathologies. A case utilizing both imaging modalities to diagnose and monitor the condition in a patient with a bleeding disorder is presented.
Solitary extramedullary plasmacytoma of the premaxilla
Authors: Murthy Vedang , Agarwal Jai Prakash , Jalali Rakesh , Chinoy Roshni F
Published: June 2003

Solitary extramedullary plasmacytoma is a rare tumour with radiotherapy playing an important role in its management. This report describes the case history of a man with a solitary extramedullary plasmacytoma at an extremely rare site, the premaxilla, that posed certain diagnostic and therapeutic dilemmas. The patient underwent surgery followed by postoperative radiotherapy. The use of two modalities of treatment for this localized tumour has been justified by briefly reviewing the literature and defining the various prognostic factors. These prognostic factors in turn should guide the treatment of these uncommon tumours.
Fluoroscopically guided percutaneous radiological gastrostomy: Technique, metholodology and pitfalls
Authors: Pitman AG , Lau PHC , Lau WFE , Beaty C , McKenzie AF
Published: June 2003

Fluoroscopically guided percutaneous gastrostomy tube placement is an uncommon but well‐established inter­‐ventional procedure. We present our experience of this procedure in a series of 23 patients, concentrating on the methodology, technique and pitfalls.
Hiding in the Bunker: Challenges for a radiation oncology department operating in the Severe Acute Respiratory Syndrome outbreak
Authors: Mukherjee RK , Back MF , Lu JJ , Shakespeare TP , Wynne CJ
Published: June 2003

In February 2003, one woman returned from Hong Kong to Singapore with a previously undescribed atypical pneumonia. Two months later, Singapore is facing its greatest ever threat to its population's health and the country's economy. The government has taken strong action to break the chain of infection of Severe Acute Respiratory Syndrome (SARS). As a radiation oncology department in Singapore, we have faced challenges in keeping staff and patients safe while continuing to provide a service to our patients. In this article, we outline the measures taken to curb SARS in Singapore and discuss the implications for Australasian radiation oncology departments.
New approach to the reproductive biology of Helicolenus dactylopterus
Authors: Sequeira V. , Figueiredo I. , Muñoz M. , Gordo L. S.
Published: June 2003

The reproductive patterns of Helicolenus dactylopterus are presented; the species is zygoparous. The first photographic record of three embryonic stages in the intraovarian gelatinous matrix is also presented.
Microsatellite variation and population genetic structure of the red throat emperor on the Great Barrier Reef
Authors: Van Herwerden L. , Benzie J. , Davies C.
Published: June 2003

Analysis (using three analytical approaches) of eight microsatellite markers from six locations in three geographic regions of the Great Barrier Reef (GBR), including populations that differed in demographic characteristics, showed no evidence of genetic stock structure in the red throat emperor Lethrinus miniatus. Measures of inter‐population differentiation were non‐significant (P ≥ 0·67). Using a Bayesian clustering approach, ‘admixture’ was detected (mean alpha values >1) with allele frequencies for each of the locations sampled being correlated equally with allele frequencies from all locations sampled. The number of populations (K) identified was one, based on the estimates of the probability of the data at various K values (K = 1, 2, 3, … 6). Additionally, alpha values did not stabilize to relatively constant values in any of the Bayesian analyses performed, indicating that there was no real genetic structure between locations. Analysis of genetic variation as detected by analysis of molecular variance (AMOVA) indicated that almost all of the variance in the data (99·74%, P ≤ 0·023) was within populations, rather than among populations (0·15%, P ≤ 0·176) or amongst regions sampled (0·10%, P ≤ 0·247) on the GBR. Fst statistics identified four individual loci having statistically significant differentiation among populations, but these were only related to one out of 12 pair‐wise comparisons where populations differed demographically. Given these results (albeit using neutral markers), together with the capacity of adults and larvae to be mobile between reefs on the inter‐connected GBR, it is considered unlikely that L. miniatus populations exist as distinct genetic stocks in the GBR. It is therefore not possible, using neutral markers, to reject the null hypothesis that the fishery be managed as a single panmictic stock.
Rodlet cells in the posterior intestine of embryos and neonates of two poeciliid species
Authors: Kramer C. R. , Potter H.
Published: June 2003

Rodlet cells occurred in the posterior intestine of embryos and neonates of the swordtail Xiphophorus nigrensis, its hybrids with Xiphophorus pygmaeus and in the platyfish Xiphophorus maculatus. This is the first observation of these enigmatic cells in a viviparous teleost prior to birth. This finding lends support to the endogenous tenet regarding the origin of this cell.
Physiological impact of sea lice on swimming performance of Atlantic salmon
Authors: Wagner G. N. , McKinley R. S. , Bjørn P. A. , Finstad B.
Published: June 2003

Atlantic salmon Salmo salar were infected with two levels of sea lice Lepeophtheirus salmonis (0·13 ± 0·02 and 0·02 ± 0·00 sea lice g−1). Once sea lice became adults, the ventral aorta of each fish was fitted with a Doppler cuff to measure cardiac output (Q̇), heart rate (fH) and stroke volume (VS) during swimming. Critical swimming speeds (Ucrit) of fish with higher sea lice numbers [2·1 ± 0·1 BL (body lengths) s−1] were significantly lower (P < 0·05) than fish with lower numbers (2·4 ± 0·1 BL s−1) and controls (sham infected, 2·6 ± 0·1 BL s−1). After swimming, chloride levels in fish with higher sea lice numbers (184·4 ± 11·3 mmol l−1) increased significantly (54%) from levels at rest and were significantly higher than fish with fewer lice (142·0 ± 3·7 mmol l−1) or control fish (159·5 ± 3·5 mmol l−1). The fH of fish with more lice was 9% slower than the other two groups at Ucrit. This decrease resulted in Q̇ not increasing from resting levels. Sublethal infection by sea lice compromised the overall fitness of Atlantic salmon. The level of sea lice infection used in the present study was lower than has previously been reported to be detrimental to wild Atlantic salmon.
Size‐dependent predator–prey relationships between perch and their fish prey
Authors: Dörner H. , Wagner A.
Published: June 2003

Size‐dependent interactions between piscivorous perch Perca fluviatilis (age ≥1 year) and their fish prey age 0 year perch, pikeperch Sander lucioperca and roach Rutilus rutilus in the biomanipulated Bautzen Reservoir indicated that the highest ratio of prey total length (LT) to predator LT was 59%. Perch LT and prey fish LT were positively and linearly related. Perch LT was strongly related with both gape width and gape height. Within the range 80–110 mm LT, the gape height of perch exceeded gape width, while beginning at 120 mm LT the gape width exceeded gape height. The minimum, maximum and mean prey LT and prey body depths of all three prey species increased with increasing predator size, but the increases in mean sizes of perch and pikeperch as prey were less than that of roach. The low limit of the ‘predation window’ observed in this study coupled with results of previous studies on perch in the Bautzen Reservoir indicated that perch had a major impact on the population dynamics of both perch and pikeperch.
Growth of young‐of‐the‐year mackerel in the Bay of Biscay
Authors: Cotano U. , Álvarez P.
Published: June 2003

The first growth season of young‐of‐the‐year (0+ year) mackerel Scomber scombrus, sampled in the Bay of Biscay, was parameterized to determine growth patterns. Daily increments were identified on sagittae otoliths, for calculation of age and growth of 92 larvae and 54 juveniles over the range 3·6–215·0 mm standard length (LS). A Gompertz curve was fitted to the length‐at‐age data. At the end of the first year of growth LS was 194·2 mm, with a maximum growth increment of c. 2 mm day−1, observed 62 days after hatching. Backcalculated growth increments for mackerel juveniles, during their larval stage, were higher than those observed for sampled larvae; only 10·9% of sampled larvae were estimated to survive. Growth for north‐eastern Atlantic mackerel was slower than that published for north‐western Atlantic mackerel. Backcalculated hatching dates for mackerel were consistent with the typical temporal distribution of mackerel spawning in the Bay of Biscay.
Enzyme activities and pH variations in the digestive tract of gilthead sea bream
Authors: Deguara S. , Jauncey K. , Agius C.
Published: June 2003

Two investigations were carried out with 150 g gilthead sea bream Sparus aurata to determine the relative activity of six digestive enzymes (pepsin, trypsin, chymotrypsin, carboxypeptidase A, carboxypeptidase B and amylase) and the pH variation in the lumen of different parts of the gut of fish fed one or two meals per day. Pepsin activity was found exclusively in the stomach, whereas activities of the other enzymes studied were found in all regions of the gut, including the stomach. The lack of localization of enzyme production in the digestive tract of S. aurata is similar to many other species as reported in the literature. The pH variations found in the different regions of the gut could be explained by general digestive physiology following the flow of digesta along the digestive tract. The range of pHs recorded in the various regions of the gut were generally outside the cited optima for many digestive proteases in this species.
Anion exchange in the giant erythrocytes of African lungfish
Authors: Jensen F. B. , Brahm J. , Koldkjær P. , Wang T. , McKenzie D. J. , Taylor E. W.
Published: June 2003

Carbon dioxide transport in African lungfish Protopterus aethiopicus blood conformed to the typical vertebrate scheme, implying a crucial and rate‐limiting role of erythrocyte Cl–/HCO3– exchange. The rate coefficient for unidirectional Cl– efflux via the anion exchanger (k, s−1) increased with temperature in African lungfish, but values were well below those reported in other species. The erythrocytes of African lungfish were, however, very large (mean cellular volume = 6940 µm3), and the ratio of cell water volume to membrane surface area was high (VwAm−1 = 1·89). Hence, the apparent Cl– permeability (PCl = kVwAm−1, µm s−1) was close to that in other vertebrates. The plot of lnPCl against the inverse absolute temperature was left‐shifted in the tropical African lungfish compared to the temperate rainbow trout Oncorhynchus mykiss, which supports the idea that PCl is similar among animals when compared at their preferred temperatures. Also, Q10 for anion exchange calculated from PCl values in African lungfish was 2·0, supporting the idea that the temperature sensitivity of erythrocyte anion exchange matches the temperature sensitivity of CO2 production and transport in ectothermic vertebrates.
Oxygen uptake of growth hormone transgenic coho salmon during starvation and feeding
Authors: Leggatt R. A. , Devlin R. H. , Farrell A. P. , Randall D. J.
Published: June 2003

Oxygen uptake of growth hormone transgenic coho salmon Oncorhynchus kisutch was measured in individual fish with a closed‐system respirometer and was compared with that of similar‐sized non‐transgenic control coho salmon during starvation and when fed a fixed ration or to satiation. Transgenic and control fish did not differ in their standard oxygen uptake after 4 days of starvation, although control fish had a higher routine oxygen uptake, scope for spontaneous activity and initial acclimation oxygen uptake. During feeding, transgenic fish ate significantly more than control fish, and had an overall oxygen uptake that was 1·7 times greater than control fish. When fish that had eaten the same per cent body mass were compared, transgenic fish had an oxygen uptake that was 1·4 times greater than control fish. Differences in oxygen uptake in growth hormone transgenic coho salmon and non‐transgenic fish appear to be due to the effects of feeding, acclimation and activity level, and not to a difference in basal metabolism.
Variation in tolerance to hypoxia in a predator and prey species: an ecological advantage of being small?
Authors: Robb T. , Abrahams M. V.
Published: June 2003

Three physiological variables, haematocrit, haemoglobin concentration and ventilation frequency, were measured to test how fathead minnows Pimephales promelas and small and large yellow perch Perca flavescens responded to three different dissolved oxygen concentrations. All fish were monitored continuously for any indications of stress in response to these manipulations. Within and between species, smaller individuals were the most tolerant of hypoxic environments. A species effect, however, did contribute to this observation, with fathead minnows being more tolerant of hypoxic environments than similar‐sized yellow perch. In aquatic ecosystems where smaller fishes are more tolerant to hypoxia than their larger predators, hypoxic environments may have the potential to act as a refuge from predators.
Morphological and life‐history differentiation between littoral and pelagic forms of pumpkinseed
Authors: Gillespie G. J. , Fox M. G.
Published: June 2003

Trophically dimorphic pumpkinseed populations were investigated in five lakes in Ontario, Canada to determine: (1) whether the morphological traits that distinguish littoral from pelagic forms are consistent among populations; (2) whether the pharyngeal jaw apparatus is diminished in pelagic pumpkinseeds because of a lower proportion of hard‐bodied prey in their diets; (3) whether there is life‐history differentiation between littoral and pelagic forms. Pumpkinseeds captured from the littoral and pelagic zones differed significantly in morphology in four of the five lakes, but the number of external measures that differed significantly within the differentiated populations ranged from zero to six. Littoral pumpkinseeds generally had longer heads, more rearward placement of dorsal and pectoral fins, longer pectoral fins and deeper bodies than pelagic pumpkinseeds. Littoral and pelagic pumpkinseeds were more readily differentiated by internal morphometric measures, with littoral individuals having larger molars and wider spacing between gill rakers than pelagic individuals. Littoral and pelagic differences in age at maturity, size at maturity and gonado‐somatic index were present only in one of three populations assessed for these traits, suggesting that morphological divergence is not necessarily accompanied by life‐history differentiation.
Habitat, diet and food assimilation of Arctic charr under the winter ice in two subarctic lakes
Authors: Klemetsen A. , Knudsen R. , Staldvik F. J. , Amundsen P.‐A.
Published: June 2003

The Arctic charrSalvelinus alpinuspopulations of the subarctic lakes Takvatn and Fjellfrøsvatn, north Norway, concentrated in the littoral zones (0–15 m) of the lakes during the entire winter (December to May) despite very low temperatures (0·2 and 0·7° C). High prey availability, low predation and competition and comparatively better light under snow and ice in shallow compared with deep water are probable reasons. At ice break in June, all Arctic charr moved to the profundal zone for a brief period, probably in response to the sudden light increase and a profundal resource peak of chironomid pupae. In the summer, the Arctic charr are found in the pelagic, profundal and littoral zones of the lakes. These populations therefore perform regular habitat shifts between the littoral zone in the winter, the profundal zone at ice break and the whole lake in the summer and autumn. The fish fed continuously during winter despite the cold water and the poor light. Amphipods and chironomid larvae dominated the diet. Catch per unit effort, numbers of stomachs with food and food intake rates varied with the subarctic light cycle but were lowest after the winter solstice. The winter assimilation of energy was about equal to the standard metabolism in Takvatn but was higher in Fjellfrøsvatn. The assimilation increased in both lakes under the spring ice in May. The habitat choice, diet and energy assimilation indicate that the Arctic charr is well adapted to the extreme winter conditions of subarctic lakes.
Growth backcalculations based on otoliths incorporating an age effect: adding an interaction term
Authors: Finstad A. G.
Published: June 2003

An extension, including an age × length interaction, was developed for a recent model incorporating the age effect in the backcalculation of growth in length from otoliths. The interaction was demonstrated using empirical data from Arctic charr Salvelinus alpinus.
Paternal effect on otolith size at emergence in masu salmon
Authors: Yamamoto T. , Reinhardt U. G.
Published: June 2003

Otolith size of emerging masu salmon Oncorhynchus masou fry was measured as a surrogate measure for standard metabolic rate in a controlled breeding study. Otolith size differed significantly among half siblings from the same dam, which suggested that standard metabolic rate of the offspring and hence their growth rate were probably paternally inherited.
Dietary–morphological relationships in a fish assemblage of the Bolivian Amazonian floodplain
Authors: Pouilly M. , Lino F. , Bretenoux J.‐G. , Rosales C.
Published: June 2003

Morphological correlates of diet were examined in 48 species of freshwater fishes from floodplain lakes in the central part of the Mamoré River (Bolivian Amazon). The species were classified, according to the percentage occurrence of seven food items, into eight broad trophic categories: mud feeders, algivores, herbivores, terrestrial invertivores and omnivores, carnivores, zooplanktivores, aquatic invertivores and piscivores. There were significant relationships between the diet and morphology of the fishes even when the effect of taxonomical relatedness between species was eliminated. Relative gut length was the main morphological variable used to order species on a carnivore to mud feeder gradient. Standard length and head and mouth size were the morphological variables most closely associated with prey size. Mud feeder, algivore and piscivore species appeared as the most dietary and morphologically specialized. These results support both the hypotheses that species morphology influences the diet and that morphological similarity is conserved even in comparison with taxonomically unrelated species.
Muscle growth in juvenile Atlantic salmon as influenced by temperature in the egg and yolk sac stages and diet protein level
Authors: Bjørnevik M. , Beattie C. , Hansen T. , Kiessling A.
Published: June 2003

Atlantic salmon Salmo salar eggs derived from a single family were incubated at two different water temperature regimes, with a mean temperature between fertilization and first feeding differing between 6 and 10° C (HT) and 2–6° C (LT). From first feed the fry were kept under the same rearing conditions and fed either high (50%) or low (45%) protein diet level of equivalent energy content until smoltification. All treatments were carried out in duplicate tanks. At first feeding the groups were similar in mass, but thereafter the HT‐fish were heavier and longer compared to the LT‐fish throughout the experiment. The groups fed the high protein diet were significantly heavier and longer compared with the corresponding low protein diet. A strong positive relationship was observed between LF and total white muscle cross‐sectional area (CSA), white muscle fibre diameter and fibre number. There were also equivalent relationships with body mass. There were no significant differences in CSA, the mean diameter or the number of white muscle fibres per CSA between groups at first feed. Muscle fibre number and CSA increased in all groups during the experiment, whereas fibre diameter reached a plateau when the fish reached > 9 cm LF. There were only minor effects of pre‐hatch and yolk sac stage temperature on CSA and fibre number per CSA during the juvenile stage. In short periods the LT‐group had larger CSA and higher fibre number than the HT‐groups, but this differences had disappeared by the end of the juvenile stage. No differences in mean fibre diameter were found between groups, except at the time of smoltification. When the fish approached smoltification a decrease in mean fibre diameter and an increase in muscle fibres <25 µm was seen and taken as an indication of recruitment of new fibres (hyperplasia). Only minor differences in CSA, fibre number or fibre diameter was observed between high and low protein diet groups.
Fish assemblage structure in the East China Sea and southern Yellow Sea during autumn and spring
Authors: Jin X. , Xu B. , Tang Q.
Published: June 2003

Based on bottom trawl surveys in autumn 2000 and spring 2001, the fish assemblage structure in the southern Yellow Sea and the continental shelf of the East China Sea was analysed. Four groups of fishes were identified for each season by the two‐way indicator species analysis (TWIA). Although seasonal migration caused a slight difference in fish assemblages between autumn and spring, two major groups of fishes, corresponding to the Yellow Sea and East China Sea were identified. Inshore and offshore groups were subsequently separated. Changes in water depth may be most important in the separation of the groups in the offshore waters of the East China Sea. Temperature affected the groupings between north and south, particularly in the central part of the Yellow Sea. Here, the cold water mass affected the species composition which was low in diversity and different from the other areas.
Hunger and light level alter response to bait by Pacific halibut: laboratory analysis of detection, location and attack
Authors: Stoner A. W.
Published: June 2003

Laboratory experiments with Pacific halibut Hippoglossus stenolepis revealed that hunger level had a significant effect on the first detection of bait, the number of baits located and attacked, the time required to locate and attack baits and handling times. In all cases, feeding motivation and efficiency increased with hunger. Light level influenced general locomotory activity and location and attacks on baits, but not detection or handling times. The effect of light was interactive with fish hunger level. Hungry fish could locate and consume baits in all light levels, ranging from daylight conditions to near darkness (10−8 µmoles photons m−2 s−1), but location, attack and handling times were all significantly elevated in low light conditions, and attack rates were significantly reduced. In the dark, only 50% of the baits were located and only 17% were attacked. Performance metrics were relatively similar among three higher light treatments (10−5, 10−3 and 10−1 µmoles photons m−2 s−1) where bait location and attack were more efficient. Active space and effective area associated with baited fishing gear will vary because hunger and light levels affect variation in bait detection, locomotion and feeding behaviour. Consequently, fishing activity and stock assessments that depend upon bait may be compromised by spatial and temporal variation in prey abundance, time of day, season, depth and other environmental variables that influence feeding motivation and efficiency.
A new knotweed‐boring species of the genus Ostrinia Hübner (Lepidoptera: Crambidae) from Japan
Authors: OHNO Suguru
Published: June 2003

A pyraustine species of the genus Ostrinia Hübner collected at Shigakogen, central Honshu, Japan is described as new to science under the name of Ostrinia ovalipennis sp. nov. This species is morphologically similar to the Far Eastern knotweed borer, Ostrinia latipennis, but is distinguishable from O. latipennis in wing marking and male genitalia. Larvae of O. ovalipennis feed on the knotweed, Reynoutria sachalinensis (Polygonaceae), as do larvae of O. latipennis. In Shigakogen, adults of the two knotweed‐boring species co‐occur in the same season. Adults of O. ovalipennis were captured only in July, suggesting that this species is univoltine. The fact that O. ovalipennis shares several morphological and ecological features with O. latipennis suggests that the species is the closest relative of O. latipennis.
The Argentine ant, Linepithema humile, in Japan: Assessment of impact on species diversity of ant communities in urban environments
Authors: TOUYAMA Yoshifumi , OGATA Kazuo , SUGIYAMA Takashi
Published: June 2003

The Argentine ant Linepithema humile (Mayr) invaded the Hiroshima Prefecture in south‐west Japan some time before 1990. In this report, we describe the distribution of this exotic ant species and assess its impact on indigenous ant communities in urban areas. L. humile is now widely distributed mainly in urban areas and surrounding secondary vegetation of the cities Hatsukaichi and Hiroshima. The impact assessment suggested that L. humile reduced species diversity of local, indigenous ant communities. There was differential sensitivity of indigenous ant species to the invasion of L. humile. Some ant species disappeared in parks infested with L. humile; for example, Pheidole noda, Pheidole indica and Lasius japonicus. L. humile seemed to be superior to these ant species in certain traits and habits, such as mobility, recruitment ability, aggressiveness and omnivory. In contrast, Paratrechina sakurae and Camponotus vitiosus were less affected by L. humile infestation. The mechanisms allowing such coexistence seemed to be small body size (P. sakurae) and arboreal nesting habits (C. vitiosus).
Seasonal changes in wing dimorphism of the lygaeid bug Dimorphopterus japonicus (Heteroptera: Lygaeidae) in relation to environmental factors
Authors: SASAKI Rikiya , NAKASUJI Fusao , FUJISAKI Kenji
Published: June 2003

The lygaeid bug Dimorphopterus japonicus Hidaka, which mainly feeds on a eulalia, Miscanthus sinensis, shows marked wing dimorphism of brachyptery and macroptery. Its production of macropters is stimulated in rearing conditions such as high temperature, long photoperiod and crowding during the nymphal stage. In this study, we investigated the seasonal prevalence in occurrence and the seasonal change in incidence of macroptery in D. japonicus for field populations in Okayama, western Japan. The results demonstrated that nymphal density was a key factor in determining the proportion of macropters, indicating an escape strategy from crowded populations. The field surveys also revealed that this bug has a univoltine life cycle in Okayama. There was a seasonal change in the incidence of macroptery in the new generation. The combined effects of temperature and photoperiod on wing‐form determination explained this seasonality trait.
Local divergence in developmental traits within a trivoltine area of Hyphantria cunea Drury (Lepidoptera: Arctiidae)
Authors: GOMI Tadashi , INUDO Mitsunori , YAMADA Daiki
Published: June 2003

To detect divergence of the introduced fall webworm, Hyphantria cunea, within its trivoltine area in Japan, developmental traits were determined in the Kobe (34°41′N) and Kumamoto (32°48′N) populations. The lower threshold temperature for development was not different between these two populations. The thermal constant for larval development was considerably smaller in the Kobe population than in the Kumamoto population. Two types of larva occurred in these populations, one with six instars and the other with seven. In the six‐instar type, the developmental period was not different between the populations in males, but the pupal weight was greater and the forewing was longer in both sexes in the Kumamoto population than in the Kobe population. In the Kumamoto population, the seven‐instar type had a longer developmental period, heavier pupa and longer forewing than the six‐instar type. The proportion of the seven‐ to the six‐instar type was greater in the Kumamoto population than in the Kobe population, resulting in the longer developmental time and greater body size of the former.
Ogasawaracris gloriosus, a new genus and species of possibly extinct grasshopper (Orthoptera: Acrididae) from the Ogasawara Islands
Authors: ITO Gen
Published: June 2003

A new grasshopper genus and species of the subfamily Eyprepocnemidinae, Ogasawaracris gloriosus, is described from the Ogasawara Islands, oceanic islands south of Japan. This species has unique characteristics, such as an extraordinarily large body, rugose and very coarse punctation on the lateral surface of the pronotum, and very strong pronotal lateral carinae. Specimens of this new species have rarely been collected and they are known only from the Ogasawara Islands. The species may already be extinct.