Two new frog species from the Litoria rubella species group from eastern Australia

The bleating tree frog (Litoria dentata) is one of the more prominent pelodryadid frogs of eastern Australia by virtue of its extremely loud, piercing, male advertisement call. A member of the Litoria rubella species group, L. dentata has a broad latitudinal distribution and is widespread from coastal and subcoastal lowlands through to montane areas. A recent mitochondrial DNA analysis showed a deep phylogeographic break between populations of L. dentata on the mid-north coast of New South Wales. Here we extended the mitochondrial survey with more geographically comprehensive sampling and tested the systematic implications of our findings with nuclear genome wide single-nucleotide polymorphism, morphological and male advertisement call datasets. While similar in appearance and in male advertisement call, our integrative analysis demonstrates the presence of three species which replace each other in a north-south series. We redescribe Litoria dentata, which is restricted to coastal north-eastern New South Wales, and formally describe Litoria balatus sp. nov., from south-eastern Queensland, and Litoria quiritatus sp. nov., from the mid-coast of New South Wales to north-eastern Victoria.

Co-morbidity in a cystic fibrosis population attending a regional clinic

Pulmonary disease remains the major cause of morbidity in patients with cystic fibrosis (CF). However, of 115 patients attending a regional CF clinic we noted 16 cases (14%) with co-morbid conditions. Of this group, 4 of 115 patients (3.5%) had renal problems including both structural and functional defects and 4 (3.5%) had neurological disorders, 3 of which were types of epilepsy. Notably, 3 of 115 patients (2.6%) had different forms of neoplasia, all of which required significant surgical and/or chemotherapeutic intervention. There is now increasing evidence of the association between digestive tract malignancy and CF, which further complicates management of these already complex cases.

Efficacy of SYBR 14/propidium iodide viability stain for the amphibian chytrid fungus Batrachochytrium dendrobatidis

The amphibian chytrid fungus Batrachochytrium dendrobatidis is a recently described pathogen that has been implicated as a causal agent in the global decline in amphibians. Research into its biology and epidemiology has frequently involved in vitro experimentation. However, this research is currently limited by the inability to differentiate between viable and inviable zoospores. Stains are frequently used to determine cell viability, and this study tested a 2-colour fluorescence assay for the detection and quantification of viable B. dendrobatidis zoospores. The results show that the nucleic acid stains SYBR 14 and propidium iodide are effective in distinguishing live from dead zoospores, and a protocol has been optimized for their use. This viability assay provides an efficient and reliable tool that will have applications in B. dendrobatidis challenge and amphibian exposure experiments.

502. COLD SHOCK DURING RAPID COOLING OF SPERM FROM A TROPICAL ANURAN, THE CANE TOAD, BUFO MARINUS

Amphibian sperm are not considered to be susceptible to cold shock injury during cooling and cryopreservation. In this study we investigated the susceptibility of the tropical bufonid, the Cane Toad (Bufo marinus) to sperm cold shock. Sperm from testes macerated in 2x Simplified Amphibian Ringer (inactivated state) were diluted 1:6 in various cryodiluents containing 10% sucrose and 10–20% glycerol or DMSO, or were used directly as undiluted controls. Samples were cooled at three cooling rates (1oC min–1, 5oC min–1 or placed directly on ice – rapid cooling) to 0oC and then either warmed to room temperature and their motility and viability assessed after activation by dilution, or cryopreserved. Cryopreserved samples were stored in liquid nitrogen for two days and thawed at room temperature before assessment of motility and sperm viability. Cooling rapidly to 0oC by directly placing samples on ice or cooling at 5oC min–1 before warming to room temperature resulted in a significant decline in motility (all means less than 40% of control motility after 30 min at room temperature) in comparison to samples cooled slowly at 1oC min–1 (all means greater than 80% motility; p < 0.05 to 0.01). Samples cryopreserved after cold shock (rapid cooling to 2oC by immediate exposure of straws to 2oC ambient temperature) versus samples cooled slowly (1oC min–1) to 2oC prior to cryopreservation had significantly lower mean post-thaw motilities (p<0.05; in the range of 40–60% motile versus 80–95% for non-cold shocked). These data together indicate that the sperm of B. marinus undergo cold shock injury prior to freezing, and that post-thaw recovery after cryopreservation of cold-shocked sperm is substantially reduced.

402. Cryopreservation of oocytes and follicular cells of the cane toad Bufo Marinus

Amphibians are currently the most threatened of all vertebrate groups with more than 30% of all known species in decline, facing extinction or recently extinct. Cryobanking of amphibian germ cells and reproductive tissues could be used to manage threatened species and provide insurance against extinction. However, cryopreservation of fully developed amphibian oocytes and whole embryos has not been achieved due to technical problems freezing such large cellular structures. As an alternative approach, we investigated the feasibility of developing protocols for the slow-cool freezing, storage and retrieval of developmentally competent amphibian ovarian follicles containing Stage I and II oocytes which are much smaller in size than later developmental stages. Ovarian follicles from euthanased Cane Toads were incubated in cryodiluents containing either glycerol or DMSO to assess cryoprotectant toxicity and response to slow cooling freezing protocols. The fluorescent live cell stain SYBR 14 and its counter stain propidium iodide was used to score the proportion of viable follicle cells before and after cryopreservation. Cryoprotectant type, concentration and exposure time all had significant effects (P < 0.05) on the viability of follicle cells, with significant interactions between these variables. Overall, glycerol was less toxic to follicle cells than DMSO. At higher concentrations, glycerol exerted high osmotic stress on oocytes, and there was evidence that DMSO triggered apoptosis in oocytes. The most effective cryopreservation protocol for stage I and II oocyte follicles resulted in a post-thaw recovery of a mean 70% of viable follicular cells. This protocol involved cryopreservation in 15% v/v glycerol, inclusion of seeding and temperature holding periods during cryopreservation, coupled with rapid thawing in a 30°C water bath. The successful cryopreservation of intact follicles in this study indicates the potential to recover functional ovarian tissues post cryopreservation for continuation of amphibian oogenesis in vitro or in vivo.

Effect of sperm concentration, medium osmolality and oocyte storage on artificial fertilisation success in a myobatrachid frog (Limnodynastes tasmaniensis)

The present study optimised artificial fertilisation and oocyte storage conditions in Limnodynastes tasmaniensis (Myobatrachidae). Data on general reproductive biology, the effect of sperm motility and concentration, medium osmolality and oocyte storage on artificial fertilisation success are presented. Egg number was most strongly correlated with bodyweight (r = 0.819). Sperm yield was correlated with testes weight (r = 0.827), which was strongly correlated with snout-vent length (r = 0.772). Optimal artificial fertilisation occurred in 0-7 mOsm kg(-1) amphibian Ringer, similar to ranid, bufonid and hylid species. High fertilisation rates were achieved using spermatozoa with little forwards progressive motility at comparatively low concentrations (3 x10(4) sperm cells mL(-1)) and with no relationship between percentage sperm motility and fertilisation success (correlation of fertilisation rate with sperm motility after activation: r = -0.145). Oocytes stored in 5 mOsm kg(-1) solutions showed no significant decline in fertilisability after 2 h, showing that swelling of the jelly surrounding the eggs does not prevent sperm from fusing with the oocyte in this species. Fertilisability of oocytes was extended to > 4 h in medium to high osmolality solutions (124-271 mOsm kg(-1)). These data allow for the future use of L. tasmaniensis in developing assisted reproductive technology protocols for foam-nesting myobatrachid species, many of which are now threatened with extinction in the wild.

Optimisation of handling, activation and assessment procedures for Bufo marinus spermatozoa

In the present study, we investigated handling, activation and assessment procedures for cane toad (Bufo marinus) spermatozoa. Optimisation of these techniques will facilitate the maintenance of sperm viability during cryopreservation and during in vitro fertilisation (IVF) techniques in reproduction technologies for endangered species. Spermatozoa were taken from testicular macerates and assessed using plasma membrane integrity assays (live/dead stains) and quantitative scores of motility parameters. In the assessment of sperm viability using live/dead stains, there were small but significant differences in the percentage of sperm from cryopreserved samples staining positive with propidium iodide, Hoechst H33258 and Trypan blue; these differences were not large and all stains performed acceptably. Spermatozoa were activated by dilution of testicular macerates in water at one of two dilution ratios (1 : 6 or 1 : 20) with or without 0.1–5.0 mm theophylline. Sperm plasma membrane integrity (unstained spermatozoa) was unaffected by either dilution ratio (osmolarity) or theophylline concentration. However, sperm motility was significantly affected by osmolarity and theophylline concentration. The stimulation of sperm motility increased with higher theophylline concentrations and these strongly interacted with lower osmolarities through a higher dilution ratio of sperm macerates with water. Spermatozoa were exposed to increasing centrifugation forces to determine tolerance to physical stresses encountered during washing procedures. Forces between 50 and 800g were associated with a significant reduction in motility (mean 56 ± 3% decreasing to 27 ± 3%), but did not affect staining. In conclusion, centrifugation should be minimised in anuran sperm washing procedures; osmotic shock associated with higher dilution ratios reduces the capacity of anuran sperm to achieve high percentages of motile sperm, leading to a likely trade-off between dilution required for activation and sperm motility to optimise IVF fertilisation rates; and optimal conditions for sperm motility after activation occur at lower dilutions of suspensions with 5.0 mm theophylline. The present study has improved protocols for the handling of anuran sperm during pre- and post-cryopreservation procedures.

Effect of sperm concentration, medium osmolality and oocyte storage on artificial fertilisation success in a myobatrachid frog (Limnodynastes tasmaniensis)

The present study optimised artificial fertilisation and oocyte storage conditions in Limnodynastes tasmaniensis (Myobatrachidae). Data on general reproductive biology, the effect of sperm motility and concentration, medium osmolality and oocyte storage on artificial fertilisation success are presented. Egg number was most strongly correlated with bodyweight (r = 0.819). Sperm yield was correlated with testes weight (r = 0.827), which was strongly correlated with snout–vent length (r = 0.772). Optimal artificial fertilisation occurred in 0–7 mOsm kg–1 amphibian Ringer, similar to ranid, bufonid and hylid species. High fertilisation rates were achieved using spermatozoa with little forwards progressive motility at comparatively low concentrations (3 × 104 sperm cells mL–1) and with no relationship between percentage sperm motility and fertilisation success (correlation of fertilisation rate with sperm motility after activation: r = –0.145). Oocytes stored in 5 mOsm kg–1 solutions showed no significant decline in fertilisability after 2 h, showing that swelling of the jelly surrounding the eggs does not prevent sperm from fusing with the oocyte in this species. Fertilisability of oocytes was extended to > 4 h in medium to high osmolality solutions (124–271 mOsm kg–1). These data allow for the future use of L. tasmaniensis in developing assisted reproductive technology protocols for foam-nesting myobatrachid species, many of which are now threatened with extinction in the wild.

Allozyme, chromosomal and morphological variability in the Litoria lesueuri species group (Anura : Hylidae), including a description of a new species

Allozyme variation at 36 loci was screened in 179 individuals of the Litoria lesueuri species group from 33 locations from across the species' range in eastern Australia. We identified three genetic groups, with discrete and disjunct distributions, that we consider to be separate species. The northernmost group, L.�jungguy, sp. nov., had a distinctive standard and C-band karyotype, while the karyotypes of the two southern groups, L. lesueuri (Duméril & Bibron, 1841) and L. wilcoxii Gunther, 1864, differed only in minor details of their C-band patterns. Stepwise discriminant function analysis of morphometric variation among 13 meristic variables was able to discriminate L. lesueuri and L. wilcoxii in 100% of cases but discrimination between L. wilcoxii and L. jungguy was less successful, with 75% and 56% of each group respectively being correctly classified. Locations with inter-group hybrids were identified in the Australian Capital Territory, mid-east Queensland and two localities in far north Queensland. However, each of the groups has a large geographic range within which there was relative allozyme and karyotype uniformity. On the basis of the genetic data, each group is herein elevated to species status. Existing types were assigned to their respective genetic groups on the basis of a discriminant function analysis. Formal taxonomic accounts are provided. The closely related L. booroolongensis (Moore, 1961), sole member of the L.�booroolongensis species group, differed allozymically from all three species of the L. lesueuri species group but only from the northern species in its karyotype. Small genetic distances between L.�booroolongensis and members of the L. lesueuri species group indicate a close relationship for the two species groups.

Evidence for continuous iteroparity in a temperate-zone frog, the red-crowned toadlet, Pseudophryne australis (Anura : Myobatrachidae)

The breeding behaviour of the red-crowned toadlet, Pseudophryne australis, was observed both in the field and in captivity. Female and male red-crowned toadlets were active in the field throughout the year. New egg masses were observed all year except mid-winter. Females returned in a gravid condition repeatedly to the breeding site over years and presumably deposited eggs, and a captive female has laid 34 clutches over 7.25 years. P. australis has evolved continuous iteroparity in a region where most frogs breed once a year, seasonally, in reliable long-lasting ponds or permanent creeks. We suggest that the comparatively extreme iteroparity observed is a result of the limitations imposed on the species in the choice of oviposition time, due to unpredictable rainfall, and of the limited availability and suitability of nesting sites. Further, iteroparity may have evolved because there is high variance in reproductive success, or particularly high recruitment losses incurred as a result of the desiccation of embryos or larvae in the ephemeral breeding sites. The adaptive response is to lay small clutches often and to gamble that follow up rains will occur on some occasions to enable recruitment. The alternative, to lay a large clutch of eggs at one time and have the ephemeral pond dry because there was no follow-up rain, would lead to total reproductive loss.

Karyotypes of South-West Pacific Ranid Frogs (Anura:Ranidae)

Karyotypes of 12 species from five genera of Australian, New Guinean and Solomon Islands ranid frogs are reported and for convenience are compared and contrasted with the 2n = 26, fundamental number (FN) = 52 karyotype of Rana, the typical karyotype of the subfamily Raninae. This karyotype was found in the four species of Rana examined. One species, Ceratobatrachus guentheri, had an increased diploid number of 30, a lower FN of 38, and altered relative lengths and centromere positions of pairs 1-5, and several of the smaller pairs. These changes could have resulted from centric fissions and pericentric rearrangements which produced an increase in the number of telocentric chromosomes. Eight species, Batrachylodes vertebralis, Discodeles bufoniformis, D. guppyi, Platymantis boulengeri, P. myersi, P. neckeri, P. solomonis and P. weberi, had reduced diploid numbers and FN. The means by which reduction in diploid number and FN has occurred in these species is unknown, but may involve centric fissions to produce telocentrics, followed by translocation onto other chromosomes, or a process involving pericentric rearrangements to produce telocentric chromosomes followed by fusion of these products. With the exception of Rana, the level of chromosomal rearrangements in the south-west Pacific ranid frogs that occur on archipelagos is high compared with that observed in the continental lineages of this subfamily.

An Electrophoretic Investigation of Relationships of Diploid and Tetraploid Species of Australian Desert Frogs Neobatrachus (Anura: Myobatrachidae)

Allozyme electrophoresis of 27 loci was used to characterise genetic variation among 29 populations of six diploid species of the myobatrachid frog genus Neobatrachus. All six species are well differentiated genetically with the percentage of fixed differences between species ranging from 11 to 59%. The genetic data are in agreement with the currently accepted species boundaries. The four tetraploid species were examined for 25 of the 27 loci assayed in the diploid species. In contrast to the diploid species, the tetraploid species shared electromorphs with each other at all the loci examined. The tetraploid species were examined for the presence of electromorphs specific to individual diploid species. The majority of these electromorphs were observed in the tetraploid species. For cases in which the range of a tetraploid species contacts that of a diploid species and the diploid population can be characterised by unique electromorphs, then evidence of current gene flow was found in the direction of the tetraploid populations. The data are compatible with single or multiple discrete or hybrid origins of the tetraploids overlain by gene flow among the tetraploids and between the tetraploids and some and perhaps all of the diploids by means of geographically limited but ongoing episodes of introgressive hybridisation.

Management and response to treatment of Helicobacter pylori gastritis

Gastritis associated with Helicobacter pylori was present in gastric biopsies from 24/95 (25%) children and adolescents undergoing endoscopy for recurrent abdominal pain and upper gastrointestinal symptoms. H pylori associated gastritis occurred mainly in older children (8-16 years) and was significantly associated with low socioeconomic class and a family history of peptic ulcer disease. Antral nodularity was a common endoscopic finding in H pylori positive children. Eighteen children, all over 5 years of age, were treated with tripotassium dicitratobismuthate (De-Nol) for two months and ampicillin for two weeks. In 12 children follow up gastric biopsies were obtained six weeks after completion of treatment. In 9/12 (75%) children H pylori was eradicated, and gastritis improved.

Immune responses to Helicobacter pylori in children with recurrent abdominal pain

The systemic immune response to Helicobacter pylori was examined in 69 children with recurrent abdominal pain and upper gastrointestinal symptoms. Twenty one (30%) children were histologically positive for H pylori. Eighteen of the 21 positive subjects and two H pylori negative subjects (one with normal mucosa, one with lymphocytic gastritis) were positive for H pylori IgG antibodies by enzyme linked immunosorbent assay (ELISA) (86% sensitivity, 98% specificity). In children with H pylori associated gastritis, there was a significant positive correlation (p less than 0.05) between IgG antibody titres and patient age. Intra-assay comparison of sera from histologically negative adults with those of histologically negative children showed that the cut off for positivity in the ELISA for adults was greater than that for children. Immunoblotting showed IgG positivity in 20 of the 21 patients with H pylori infection (95% sensitivity). Both ELISA and immunoblotting for IgA and IgM H pylori antibodies had poor discriminatory value for determining infection. Serological detection of H pylori IgG antibodies seems to be valuable in the assessment of children presenting with recurrent abdominal pain and other gastrointestinal symptoms, but assays must first be validated in paediatric populations.

Heteromorphic sex chromosomes in the Australian frog Crinia bilingua (Anura: Myobatrachidae)

The karyotype of Crinia bilingua was examined and analysed with standard staining, C-banding, and silver-staining. Heteromorphic sex chromosomes of the ZW ♂/ZZ ♀ type were observed. The larger W chromosome is submetacentric and the smaller Z chromosome is acrocentric. The centromere and proximal region of the short arm of the W chromosome consist of constitutive heterochromatin (C-band region), and beyond this is a small euchromatic terminal region. The centromere of the Z chromosome did not C-band. The long arms of the Z and W chromosomes are euchromatic and equal in length. The nucleolar organiser region occurs terminally on the long arm of both the Z and W chromosomes, and there is no cytological evidence for inactivity of the nucleolar organiser region on the W chromosome. These features indicate an early stage in the evolution of heteromorphic sex chromosomes.Key words: heteromorphic sex chromosomes, frog, Crinia bilingua.

Motor disorders of the oesophagus in gastro-oesophageal reflux

Mechanisms of gastro-oesophageal reflux were studied by oesophageal manometry and pH monitoring in 33 children: nine controls, 15 with gastro-oesophageal reflux alone, and nine with reflux oesophagitis. A total of 122 episodes of reflux were analysed in detail: 82 (67%) were synchronous with swallowing and 40 (33%) asynchronous. Infants with trivial symptoms had gastro-oesophageal reflux synchronous with swallowing, whereas those with serious symptoms had slower acid clearance and asynchronous reflux. There were significant differences in lower oesophageal sphincter pressure and amplitude of oesophageal contractions between controls and patients with both gastro-oesophageal reflux and reflux oesophagitis. In reflux oesophagitis there was a decrease in lower oesophageal sphincter pressure and the contractions had a bizarre waveform suggesting a neuropathic process.

Campylobacter pylori gastritis

Campylobacter pylori colonisation of the stomach is strongly associated with type B non-autoimmune gastritis in adults. In a retrospective study of 38 gastric biopsy specimens taken during upper gastrointestinal endoscopy in children attending this hospital we found C pylori in nine (24%). Ten biopsy specimens showed histological evidence of gastritis and C pylori was found in eight.

Budd-Chiari syndrome treated by Senning operation

Budd-Chiari syndrome was diagnosed in a 13 year old boy who presented with ascites. Angiographic studies showed occlusion at the ostia of the hepatic veins. This was treated surgically by the Senning operation of transcaval dorsocranial resection of the liver and hepatocaval anastomosis. The patient's ascites cleared and he remains well 10 months after surgery.

Brain stem glioma presenting as gastro-oesophageal reflux

Brain stem gliomas may present as gastro-oesophageal reflux. In such cases gastro-oesophageal reflux presents atypically late, and computed tomography may not detect the presence of the tumour until late in the course of the disease.

Modification of oral methotrexate absorption in children with leukemia

The effect of administering oral methotrexate in different formulations to children with acute lymphoblastic leukemia was evaluated. Methotrexate tablets alone achieved higher mean plasma levels and larger area under the absorption curve than either methotrexate liquid alone or methotrexate tablets taken concurrently with metoclopramide.

Polyploidy in the australian leptodactylid frog genus Neobatrachus

Karyotypic analysis of six species of the Australian leptodactylid frog genus Neobatrachus showed that N. pictus, N. centralis, N. pelobatoides and N. wilsmorei are diploid (2n = 24) while N. sudelli and N. sutor are tetraploid (4n = 48). Polyploidy has not been reported previously among Australian anurans. Idiograms of the six species indicate that they are similar to the other Australian leptodactylids so far discribed. DNA values of the tetraploids are approximately double the values for diploids. Tetraploid nuclear and cell sizes are greater compared with diploids but total body size shows no increase. At diakinesis in primary spermatocytes of tetraploids, mainly tetravalents together with a few bivalents are present. Silver straining of metaphase spreads clearly demonstrates the location of NORs at the secondary constrictions and their frequent association in the tetraploid N. sutor. Nucleolar number in interphase nuclei provides a reliable guide for distinguishing tetraploid from diploid frogs in the absence of chromosome analysis and can be determined for both living and preserved specimens. The possible origins and relationships of the tetraploid species are discussed.