Taxonomy and biology of two new species of gall midge (Diptera: Cecidomyiidae) infesting Sarcocornia quinqueflora (Chenopodiaceae) in Australian salt marshes

Two new species of gall midge associated with two distinct galls on the succulent creeping shrub Sarcocornia quinqueflora are described from salt marshes in south-eastern Australia. The infestations caused by the new species hinder the growth of S. quinqueflora, the seeds of which are the major food of the critically endangered orange-bellied parrot Neophema chrysogaster. Asphondylia floriformis sp. n. Veenstra-Quah & Kolesik transforms leaf segments into flower-like galls, whereas Asphondylia sarcocorniae sp. n. Veenstra-Quah & Kolesik produces simple swellings on branches. Both galls have fungal mycelium growing in the apoplast of the gall tissue and lining the inner surface of the larval chamber where it is presumably grazed by the larva. Descriptions of the larvae, pupae, males, females and the geographical distribution of the two gall midges in south-eastern Australia are given.

Heterozygous tx mice have an increased sensitivity to copper loading: implications for Wilson's Disease carriers

Wilson's disease carriers constitute 1% of the human population. It is unknown whether Wilsons disease carriers are at increased susceptibility to copper overload when exposed to chronically high levels of ingested copper. This study investigated the effect of chronic excess copper in drinking water on the heterozygous form of the Wilson’s disease mouse model – the toxic milk (tx) mouse. Mice were provided with drinking water containing 300 mg/l copper for 4–7, 8–11, 12–15 or 16–20 months. At the completion of the study liver, spleen, kidney and brain tissue were analyzed by atomic absorption spectroscopy to determine copper concentration. Plasma ceruloplasmin oxidase activity and liver histology were also assessed. Chronic copper loading resulted in significantly increased liver copper in both tx heterozygous and tx homozygous mice, while wild type mice were resistant to the effects of copper loading. Copper loading effects were greatest in tx homozygous mice, with increased extrahepatic copper deposition in spleen and kidney – an effect absent in heterozygote and wild type mice. Although liver histology in homozygous mice was markedly abnormal, no histological differences were noted between heterozygous and wild type mice with copper loading. Tx heterozygous mice have a reduced ability to excrete excess copper, indicating that half of the normal liver Atp7b copper transporter activity is insufficient to deal with large copper intakes. Our results suggest that Wilsons disease carriers in the human population may be at increased risk of copper loading if chronically exposed to elevated copper in food or drinking water.

Modulation of tumor necrosis factor receptors 1 and 2 in chronic hepatitis B and C: The differences and implications in pathogenesis

Tumor necrosis factor (TNF) plays a role in the pathogenesis of chronic hepatitis B (CHB) and chronic hepatitis C (CHC). The difference in the cytokine responses between hepatitis B virus (HBV) and hepatitis C virus (HCV) infections may have implications in the pathogenesis of these diseases. We performed a comparative study to examine the possible differences in the TNF-TNF receptor (TNFR) response between CHB and CHC. We studied the cytokine levels of 38 patients with CHB, 40 patients with CHC and 9 patients with dual hepatitis B and C, and compared them with the baseline levels of 12 healthy controls. The plasma levels of TNF-, interferon-, interleukin (IL)-2, IL-4, IL-10 and soluble TNFR-1 and 2 (sTNFR-1 and 2) were quantified by enzyme-linked immunosorbent assays. The expression of TNFR-1 and 2 in liver tissues was examined in 30 cases of CHB and 15 cases of CHC by semiquantitative reverse transcription polymerase chain reaction. The results showed that sTNFR-1 levels correlated with liver inflammation in all patients, whereas this correlation was not found with sTNFR-2 or other cytokines. Liver inflammation indicators were higher in HCV RNA+ than in HCV RNA– CHC. Most significantly, sTNFR-1 levels correlated with liver inflammation in CHB, but not in CHC. However, the expression of TNFR-1 and 2 in liver was similar between CHB and CHC. These findings suggest that the TNFR signal transduction pathway is modulated differently in HBV and HCV infection.

Electrospun nanofibre membranes as wound dressing materials

An effective wound dressing is not only able to protect the wound area from its surroundings to avoid infection and dehydration, but also to speed up the healing process by providing an optimum microenvironment for healing, removing any excess wound exudates, and allowing continuous tissue reconstruction. In this study, two biodegradable polymers, polycaprolactone (PCL) and polyvinyl alcohol (PVA), were used to electrospin nanofibre membranes. The wound dressing performances of these two membranes were compared with the wound dressing performances of protein coated membranes and conventional non-woven cotton wound dressings. In addition, fibre morphology, porous structural property, mechanical properties of the nanofibre membranes, and their drainage capacity and wound skin histology were examined.

Osmoregulatory balance in Murray cod, Maccullochella peelii peelii (Mitchell), affected with chronic ulcerative dermatopathy

This study examined the osmoregulatory capability of Murray cod, Maccullochella peelii peelii, affected by chronic ulcerative dermatopathy (CUD) in intensive aquaculture. This condition appears to arise only in facilities utilizing groundwater, with the causative agent suggested to be a water-borne factor. Healthy Murray cod (~ 700 g) were transferred to a CUD-affected farm to monitor the progression of the syndrome and began to show signs of CUD after approximately five months. In order to evaluate possible effects of CUD on osmoregulation; plasma electrolyte concentrations, osmolality, and Na⁺,K⁺-ATPase activities were measured, and gill histology and immunohistochemistry were analyzed. Plasma electrolyte concentrations and osmolality of CUD-affected Murray cod were consistent with reference values determined for non CUD-affected fish. A greater number of gill mucous cells were observed in Murray cod cultured at the CUD-affected farm compared to non CUD-affected fish. We also found an un-identified cell type that was present solely in the gills of CUD-affected Murray cod. Gill Na⁺,K⁺-ATPase activity was significantly higher in severely CUD-affected Murray cod compared to individuals transferred to the CUD-affected farm. While there appeared to be some minor changes in the gills of CUD-affected fish, this study demonstrated that Murray cod were able to effectively osmoregulate, although, perhaps at an energetic cost.

Potential endocrine disruption of ovary synthesis in the Christmas Island red crab Gecarcoidea natalis by the insecticide pyriproxyfen

The effect of the insecticide, pyriproxyfen on early ovary synthesis was examined in the Gecarcinid land crab, Gecarcoidea natalis. Crabs were fed a mixture of either leaf litter and bait containing 0.5% (wt/wt) pyriproxyfen (experimental groups), or a mixture of leaf litter and a control bait containing no pyriproxyfen (control groups), at simulated baiting doses of 2 kg ha− 1 and 4 kg ha− 1, during the period in which G. natalis synthesises its ovaries. A third group of crabs were fed ad libitum either the bait containing 0.5% Pypriproxyfen or the control bait. Pyriproxyfen affected early ovary development in G. natalis. The ovaries from crabs in the experimental groups at all baiting levels had a higher total nitrogen content and dry mass than the ovaries from crabs in the control groups. Pyriproxyfen affected the histology of the ovaries. Ovaries from animals in the experimental groups were more mature, containing more previtellogenic and early vitellogenic oocytes, of a larger diameter, than the ovaries from crabs in the control groups. Significant amounts of pyriproxyfen accumulated within the midgut gland and ovary, the hypothesised target tissues, while minor amounts of pyriproxyfen was accumulated in the muscle, a hypothesised non target tissue. Pyriproxyfen may have stimulated early ovary development and induced synthesis of yolk protein by mimicking methyl farnesoate and thus causing endocrine disruption. Given this, pyriproxyfen should not be used to control invasive insects in environments where gecarcinid and other land crab species are present.

Histological assessment of intermediate - and long-term creatine monohydrate supplementation in mice and rats

Creatine monohydrate (CrM) supplementation appears to be relatively safe based on data from short-term and intermediate-term human studies and results from several therapeutic trials. The purpose of the current study was to characterize pathological changes after intermediate-term and long-term CrM supplementation in mice [healthy control and SOD1 (G93A) transgenic] and rats (prednisolone and nonprednisolone treated). Histological assessment (18-20 organs/tissues) was performed on G93A mice after 159 days, and in Sprague-Dawley rats after 365 days, of CrM supplementation (2% wt/wt) compared with control feed. Liver histology was also evaluated in CD-1 mice after 300 days of low-dose CrM supplementation (0.025 and 0.05 g · kg^-1 · day^-1) and in Sprague-Dawley rats after 52 days of CrM supplementation (2% wt/wt) with and without prednisolone. Areas of hepatitis were observed in the livers of the CrM-supplemented G93A mice (P < 0.05), with no significant inflammatory lesions in any of the other 18-20 tissues/organs that were evaluated. The CD-1 mice also showed significant hepatic inflammatory lesions (P < 0.05), yet there was no negative effect of CrM on liver histology in the Sprague-Dawley rats after intermediate-term or long-term supplementation nor was inflammation seen in any other tissues/organs (P = not significant). Dietary CrM supplementation can induce inflammatory changes in the liver of mice, but not rats. The observed inflammatory changes in the murine liver must be considered in the evaluation of hepatic metabolism in CrM-supplemented mice. Species differences must be considered in the evaluation of toxicological and physiological studies.

The effect of vitamin : a deficiency on glucose uptake in the rat

This thesis describes an investigation of the effects of vitamin A deficiency on gut function, The central hypothesis to be tested was that acute vitamin A deficiency affects glucose uptake from the small intestine- The hypothesis was tested using a system involving perfusion of isolated segments of the small intestine in the anaesthetized rat. The system was used to study effects on glucose uptake under steady-state conditions. In the initial part of the study, experiments were diverted towards setting up the system for measuring steady-state uptake, and determining the relative contributions of active uptake and diffusion. Phenol red was found to be a reliable non-absorbable marker for determining net water movement. Phlorizin, generally at 1 mmol/L, was used as a competitive (reversible) inhibitor of active uptake. It is difficult however to confirm complete inhibition of active uptake by phlorizin because of the limited solubility of the inhibitor. The kinetics of glucose uptake f ram intra-luminal maltose were found to be, in general, not significantly different from those applying to the uptake of glucose from an equivalent glucose solution. Maltase activity in the perfused gut segment was found to be sufficient to hydrolyse most of the maltose (80 per cent or more) in the solution being perfused, a much greater proportion than was absorbed. Glucose absorptive capacity, measured on an intestinal dry weight basis, was greatest in the duodenum and progressively less in the jejunum and ileum. The rate of water uptake f ran the gut was increased by the presence of glucose in the lumen, and was linked to glucose uptake as shown by the inhibition of water uptake by phlorizin. Uptake of glucose by solvent drag was demonstrated by showing an increased rate of glucose uptake when the rate of water uptake was increased by perfusing a solution of reduced osmotic pressure. In the experiment a low intra-luminal glucose concentration was used to preclude net uptake by diffusion and active uptake was blocked with phlorizin. This process was further investigated using streptozotocin-diabetic rats in which the diabetes establishes a hyperosomotic blood with hyperglycaemia. Uptake by solvent drag was more obvious in diabetic animals. A back-diffusion (exsorption) of glucose from the tissues to the lumen was also shown; the rate being proportional to plasma glucose concentration. Vitamin A deficiency was established in weanling rats after 6-7 weeks feeding on a diet based on wheat starch, coconut oil, and casein washed with hot ethanol, together with vitamins and minerals. The vitamin A deficiency led to classic eye signs and was reversed by the addition to the diet of retinoic acid (5 g/g diet). Vitamin A deficiency decreased intestinal mucus production (dry weight) but had no detectable effect on the histology of the villous epithelium as shown under the light microscope. Using perfusion experiments it was shown that vitamin A deficiency had no significant effect on the rate of active uptake of glucose, but that deficiency increased the rate of passive uptake.

Nutritional related aspects of the artificial propagation and larval rearing of Macquarie perch, Macquaria Australasica (Cuvier, 1830)

Studies the underlying role of nutrition in the lack of response of captive fish to hypophysation. Aspects studied include morphological characteristics, histology of ovaries, proximate analysis, fatty and amino acid profiles of oocytes, muscle, liver and diets of wild and tank-reared fish, egg and larval quality, amino acid composition of eggs and larvae at different developmental stages, larval feeding and hormone treatments.

Natural history of hepatitis B in perinatally infected carriers

Objectives: To establish natural seroconversion rates and incidence of hepatic pathology in perinatally infected hepatitis B carriers.

Methods: Seventy three perinatally infected hepatitis B carriers identified through maternal screening were evaluated. Fifty three were born to parents from the Indian subcontinent, nine were Oriental, six were Afro-Caribbean, and five were white. Median follow up was 10.24 (range 2.02–20.16) years.

Results: Only three of the children followed up had cleared hepatitis B surface antigen during this period, and 30% of the children had seroconverted to anti-HBe. Seroconversions to anti-HBe were observed in Asian (18/50) and white (4/5) children, but not in Oriental or Afro-Caribbean children. More girls (40%) than boys (23%) had seroconverted, but the difference was not significant. All children were asymptomatic with normal physical examination, growth, and development. Almost half (48%) of the hepatitis B e antigen (HBeAg) positive children had normal hepatic transaminases and liver function. Thirty five liver biopsies were performed in children with active virus replication (HBeAg or hepatitis B virus DNA positive) who were being considered for antiviral treatment as part of a clinical trial and were scored using the Ishak method. Two thirds (62%) of the children had mild hepatitis, 60% had mild fibrosis, and 18% had moderate to severe fibrosis. There was a weak correlation between histological evidence of hepatitis and hepatic transaminase activity, implying that biochemical monitoring of hepatic disease activity may be ineffective.

Conclusions: These asymptomatic hepatitis B virus carrier children remain infectious in the medium to long term with notable liver pathology. They should receive antiviral treatment to reduce infectivity and to prevent further progression of liver disease. Hepatic transaminases alone are not a reliable marker of liver pathology, and liver histology is essential before consideration for antiviral treatment.

Goblet cell carcinoid tumors (adenocarcinoid) of the appendix

Purpose: Goblet cell appendiceal carcinoids represent rare tumors that exhibit histologic features of both adenocarcinomas and neuroendocrine tumors. We present the long-term results of a series of 15 patients, focusing on clinical manifestations, diagnosis, and management.

Methods: Eight male and seven female patients (median age, 52.8 years) were included. Final diagnosis was confirmed by histology. Patients were evaluated clinically, biochemically, and radiologically every four months. Median follow-up was 30 months.

Results: The majority of patients (7/15) presented with symptoms compatible with acute appendicitis. Right hemicolectomy was performed in all except one, who subsequently developed metastases. Three patients had metastases at previous diagnosis. Plasma chromogranin-A was slightly elevated in two of them, while urinary 5-hydroxy-indol-acetic acid was normal. 111Indium-labeled octreotide scintigraphy was positive only in two of the four patients with metastases. Ki67 index was greater than 20 percent in all of them, while in only one with local tumor. Combination chemotherapy with either cisplatin plus etoposide or with 5-fluorouracil, cisplatin, and streptozotocin was administered to all patients with metastases resulting in temporary stabilization of disease. Twelve patients are alive, while three died of their disease 9, 13, and 14 months after diagnosis.

Conclusions: The diagnostic value of chromogranin-A, urinary 5-hydroxy-indol-acetic acid, and 111Indium-labeled octreotide scintigraphy seems to be limited in these tumors. Ki67 index appears to predict tumor behavior. Right hemicolectomy may reduce the risk of developing metastases. Chemotherapy may have efficacy in metastatic disease, however, more data are required to determine this and the optimal regimen.

Histological alterations in the Antarctic cod, Trematomus bernacchii from Davis Station, East Antarctica

During the summer season 2009/10, a comprehensive environmental impact assessment of the sewage discharge was conducted at Davis Station in the Vestfold Hills region of East Antarctica. As part of this project, a survey of the histology of liver, gill, gonad and muscle tissues in the Antarctic rock cod Trematomus bernacchii from nearshore sites in the receiving environment close to Davis Station in was completed. Fish from 4 sites were examined; 1 site adjacent to the Davis Station sewage outfall (within 500 m of the point of discharge), 2 sites approximately 2 km from the outfall (Anchorage Island and Antennae farm), and 1 site approximately 10 km away from the outfall and adjacent to an Adelie penguin population (Kazak Island). All fish sampled from the sewage outfall site exhibited significant histological alterations in all major tissues. Fish from the other 3 sites showed some alterations in either gill and/or liver tissues. Pathological abnormalities present in all fish collected near the sewage outfall included: extensive multifocal cysts of unknown etiology with necrotic liquification; multifocal granuloma with associated inflammation; coagulative necrosis in the liver; and lamellar hyperplasia with associated proliferation and lamella fusion of the gills. Results of this work form part of a weight of evidence approach alongside ecological monitoring, chemical analysis, ecotoxicological testing and dispersal modelling of the discharge plume which is being used to inform and direct upgrades to the Australian Antarctic Divisions operations and current sewage discharge practises at Davis Station.

Histological health indices : linking complex pollutant exposure with tissue alteration in sand flathead Platycephalus bassensis

Port Phillip Bay, Victoria, is a pollutant-impacted environment that is extensively fished both professionally and recreationally. Consumption of contaminated fish represents a potential threat to human health, and fish exposed to environmental contaminants may themselves be affected in a similar fashion. This study describes a fish health index based on histological alterations identified in multiple organs of the sand flathead Platycephalus bassensis. Alterations were evident in tissues from all individuals assessed, with common pathologies observed in the gills, skin, kidney, liver and spleen. Alterations commonly present included necrosis, melanomacrophage centres, inflammation and multiple alterations of the gill epithelium (e.g. hyperplasia and hypertrophy). Fish health, calculated using severity of histological alterations, differed significantly across Port Phillip Bay, with heavily industrialized regions of Altona and St. Helens showing greatest alteration prevalence across multiple organs. This study indicates that the health of P.bassensis from Altona, St. Helens, and Mornington to a lesser extent, are currently compromised, potentially due to complex pollutant exposures which require further investigation

Hydrogen sulfide attenuates carbon tetrachloride-induced hepatotoxicity, liver cirrhosis and portal hypertension in rats

BACKGROUND : Hydrogen sulfide (H(2)S) displays vasodilative, anti-oxidative, anti-inflammatory and cytoprotective activities. Impaired production of H(2)S contributes to the increased intrahepatic resistance in cirrhotic livers. The study aimed to investigate the roles of H(2)S in carbon tetrachloride (CCl(4))-induced hepatotoxicity, cirrhosis and portal hypertension.

METHODS AND FINDINGS : Sodium hydrosulfide (NaHS), a donor of H(2)S, and DL-propargylglycine (PAG), an irreversible inhibitor of cystathionine γ-lyase (CSE), were applied to the rats to investigate the effects of H(2)S on CCl(4)-induced acute hepatotoxicity, cirrhosis and portal hypertension by measuring serum levels of H(2)S, hepatic H(2)S producing activity and CSE expression, liver function, activity of cytochrome P450 (CYP) 2E1, oxidative and inflammatory parameters, liver fibrosis and portal pressure. CCl(4) significantly reduced serum levels of H(2)S, hepatic H(2)S production and CSE expression. NaHS attenuated CCl(4)-induced acute hepatotoxicity by supplementing exogenous H(2)S, which displayed anti-oxidative activities and inhibited the CYP2E1 activity. NaHS protected liver function, attenuated liver fibrosis, inhibited inflammation, and reduced the portal pressure, evidenced by the alterations of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), albumin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and soluble intercellular adhesion molecule (ICAM)-1, liver histology, hepatic hydroxyproline content and α-smooth muscle actin (SMA) expression. PAG showed opposing effects to NaHS on most of the above parameters.

CONCLUSIONS :  Exogenous H2S attenuates CCl4-induced hepatotoxicity, liver cirrhosis and portal hypertension by its multiple functions including anti-oxidation, anti-inflammation, cytoprotection and anti-fibrosis, indicating that targeting H2S may present a promising approach, particularly for its prophylactic effects, against liver cirrhosis and portal hypertension.