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PubMed2006

Photosynthesis and sink activity of wasp-induced galls in Acacia pycnantha.

Although insect galls are widely known to influence source-sink relationships in plants, the relationship between photosynthesis and gall activity has not been extensively studied. In this study we used 14CO2, photosynthesis, and respiration measurements to examine the capacity of bud galls induced by the wasp Trichilogaster signiventris (Pteromalidae) as carbon sinks in Acacia pycnantha. Galls of this species develop either in vegetative or reproductive buds, depending on the availability of tissues at different times of the year, and effectively eliminate seed production by the plant. Photosynthetic rates in phyllodes subtending clusters of galls were greater than rates in control phyllodes, a result we attributed to photosynthesis compensating for increased carbon demand by the galls. Contrary to previous studies, we found that photosynthesis within galls contributed substantially to the carbon budgets of the galls, particularly in large, mature galls, which exhibited lower specific respiration rates allowing for a net carbon gain in the light. To determine the sink capacity and competitive potential of galls, we measured the proportion of specific radioactivity in galls originating from either vegetative or reproductive buds and found no difference between them. The proportion of the total amount of phyllode-derived 14C accumulated in both clustered and solitary galls was less than that in fruits. Galls and fruits were predominantly reliant on subtending rather than on distant phyllodes for photosynthate. Solitary galls that developed in vegetative buds constituted considerably stronger sinks than galls in clusters on inflorescences where there was competition between galls or fruits for resources from the subtending phyllode. Wasps developing in solitary vegetative galls were correspondingly significantly larger than those from clustered galls. We conclude that, in the absence of inflorescence buds during summer and fall, the ability of the wasps to cause gall formation in vegetative tissues tempers intraspecific competition and substantially increases the availability of plant resources for the development of wasps in such galls.

Acacia↗
PubMed1980

HIDA scanning in gall-bladder disease.

HIDA labelled with 99Tcm is a new hepatobiliary imaging radiopharmaceutical which is selectively taken up by the liver and excreted into the biliary tree; it has been shown to demonstrate the gall bladder in normal subjects. Using a gamma-camera computer system, dynamic liver scans were performed during the first hour on 97 patients who, on the basis of standard investigations and on the findings at surgery, were divided into six groups as follows. 1. Normal. 2. Hepatocellular disease. 3. Biliary obstruction. 4. Chronic gall-bladder disease. 5. Acute gall-bladder disease. 6. Acute abdomen (not due to gall-bladder disease). Pictures were taken and activity-time curves of "regions of interest" were generated from the computer data. From these the presence or absence of a gall-bladder image was easily determined. The gall bladder was visualized in all normals but in none of the patients with acute gall-bladder disease. In the group with an acute abdomen suggestive of acute gall-bladder disease, but subsequently shown to be otherwise, the gall bladder was visualized in all cases. The gall bladder was not visualized in 42% of hepatocellular disease patients, nor in any of those with biliary obstruction, due to poor uptake or poor secretion of the HIDA. In cases of chronic gall-bladder disease, visualization of the gall bladder corresponded with gall-bladder opacification on the oral cholecystogram; in these cases the HIDA scan offers no advantage over the oral cholecystogram. These results suggest that in cases of "acute abdomen" an absent gall bladder image with a normal hepatogram will strongly support the diagnosis of acute gall-bladder disease, and that visualization of the gall bladder excludes such a diagnosis, making the HIDA scan a useful first-line investigation in these patients.

Abdomen, Acute↗
PubMed1996

Longterm effects of endoscopic sphincterotomy on gall bladder motility.

BACKGROUND: Some of patients with an intact gall bladder develop acute cholecystitis or have gall bladder stone formation after endoscopic sphincterotomy. Endoscopic sphincterotomy may affect gall bladder motility. AIMS: To prospectively evaluate longterm effect of endoscopic sphincterotomy on gall bladder motility. PATIENTS: Thirty two patients with an intact gall bladder (15 with and 17 without gall bladder stones) who underwent endoscopic sphincterotomy for choledocholithiasis. METHODS: Gall bladder function was examined before and at from seven days to five years after sphincterotomy. Gall bladder volume, at fasting and after caerulein administration, was determined by ultrasonography. RESULTS: After endoscopic sphincterotomy, the enlarged orifice remained patent during a five year follow up period. One patient with gall bladder stones subsequently developed acute cholecystitis, the remaining being asymptomatic. In the patients before sphincterotomy, particularly in those with gall bladder stones, the gall bladder showed larger fasting volume and lower caerulein stimulated maximum contraction than normal controls. Throughout five years after sphincterotomy, fasting volume of the gall bladder decreased and its maximum contraction increased, regardless of gall bladder stones; significantly different from the values before sphincterotomy (p < 0.05). CONCLUSIONS: Endoscopic sphincterotomy decreases fasting volume of the gall bladder and increases its contraction ability for a long period. These changes may rather decrease the risk of future acute cholecystitis or gall stone formation.

Adult↗
PubMed2003

Expression and regulation of scavenger receptor class B type I (SR-BI) in gall bladder epithelium.

BACKGROUND AND AIMS: Biliary lipid absorption by the gall bladder mucosa and the cholesterol content of the gall bladder wall appear to play a role in cholesterol gall stone formation. As the scavenger receptor class B type I (SR- BI) regulates cellular cholesterol uptake, we studied its expression in human and murine gall bladders, its regulation by increased biliary lipid content, and its role in gall stone formation. METHODS AND RESULTS: Using immunohistochemistry, SR-BI was found in the apical domain of human gall bladder epithelial cells. Immunoblotting of isolated membranes from gall bladder epithelial cells showed a specific signal for the 82 kDa SR-BI protein. In C57BL/6 mice, SR-BI was also found in the gall bladder epithelium. Using western blot analysis, an inverse relationship was observed between biliary cholesterol concentration and SR-BI expression in murine gall bladder mucosa. By comparing lithogenic diet fed wild-type and SR-BI deficient mice, gall bladder wall cholesterol content and gall stone formation were not found to be dependent on SR-BI expression. CONCLUSIONS: (i) SR-BI is expressed in both human and murine gall bladder epithelium; (ii) biliary cholesterol hypersecretion is associated with decreased gall bladder SR-BI expression in mice; and (iii) murine SR-BI is not essential in controlling gall bladder wall cholesterol content and gall stone formation during diet induced cholelithiasis.

Animals↗
PubMed2004

The evolution of host plant manipulation by insects: molecular and ecological evidence from gall-forming aphids on Pistacia.

One of the most striking characteristics of gall-forming insects is the variability in gall position, morphology, and complexity. Our knowledge of the driving forces behind the evolutionary divergence of gall types is limited. Natural enemies, competition, and behavioral constraints might be involved. We present a cladogram, based on sequences of COI and COII (1952bp), of mitochondrial DNA for the evolution of 14 species of gall-forming aphids (Fordinae). These insects induce five gall types with remarkable morphological variation on Pistacia spp. hosts. The parsimony cladogram divides the Fordinae into three lineages, Fordini and Baizongiini, and a third (new) sister group including the previously Fordini member, Smynthurodes betae (West). We then use ecological data to trace and explain the evolution of gall morphology. The aphids seem to have evolved gradually towards better ability to manipulate their host plant, induce stronger sinks, and gain higher reproductive success. We suggest that the ancestral gall type was a simple, open, "pea"-sized gall located on the leaflet midvein. Some Fordini and S. betae evolved a two-gall life cycle, inducing a new gall type on the leaflet margin. The Baizongiini improved the manipulation of their host by inducing larger galls near the midvein, with stronger sinks supporting thousands of aphids. Similar gall types are induced at similar sites on different Pistacia hosts suggesting control of the aphids on gall morphology and frequent host shifts. Thus, even extreme specialization (specific gall and host) is flexible.

Animals↗
PubMed2003

Enhanced invertase activities in the galls of Hormaphis hamamelidis.

Invertases are sucrose hydrolyzing enzymes often associated with plant tissues acting as physiological sinks, and plant galls are physiological sinks. We investigated several types of invertase and their potential benefits in galls of the aphid Hormaphis hamamelidis. Invertase activities in galls differed from those in leaves throughout the growing season. Vacuolar invertase activities (per g FW) were always greater in galls than leaves. In contrast, cell wall invertase activities per g FW started low in galls, but increased with time and were greater than those in leaves after 1 month. Gall growth was most closely related to vacuolar invertase activity, whereas leaf growth was correlated with both vacuolar and cell wall invertase activities. In separate correlational studies of aphid fecundity and invertase activities, cell wall invertase activity per gall accounted for 15-21% of the variation in offspring per gall. Gall dry weight explained more of the variation in offspring per gall (34.2%) than did gall volume (17.8%), a likely indication of the importance of sink strength over the life of the gall. Increased invertase activity probably underlies the enhanced sink strength commonly observed in galls. Hormaphis hamamelidis fundatrices appear to maximize reproductive output by eliciting multiple beneficial responses from their hosts. Initial gall growth correlated positively with high vacuolar invertase activity, while later in the season aphid fecundity correlated positively with cell wall invertase activity.

Animals↗
PubMed1998

Effect of endoscopic sphincterotomy on gall bladder bile lithogenicity and motility.

BACKGROUND: Endoscopic sphincterotomy has been shown to inhibit stone formation in the gall bladder of experimental animals. AIMS: To investigate the alterations in bile composition and gall bladder motility after endoscopic sphincterotomy. PATIENTS: A study was performed of gall bladder bile composition and gall bladder motility in patients with gallstone disease ((n = 20; age 40-60 years, median age 55 years: seven men), with gall bladder calculi (n = 12) and with diseased gall bladder (chronic inflammation) without gall bladder calculi (n = 8)), who had received endoscopic sphincterotomy for common bile duct stones. Age and sex matched disease controls comprised 20 patients with gallstone disease but without stones and an intact sphincter of Oddi (with gall bladder calculi (n = 10) and diseased gall bladder without gall bladder calculi (n = 10)). METHODS: Gall bladder motility was assessed by ultrasound. Duodenal bile collected by nasoduodenal tube after stimulation of gall bladder by intravenous ceruletid infusion was analysed for cholesterol, phospholipid, and bile acid concentrations, cholesterol saturation index, and nucleation time. RESULTS: There was a significant reduction in mean (SEM) fasting volume (12.5 (1.7) ml v 26.4 (2.5) ml; p < 0.001) and mean (SEM) residual volume (4.34 (0.9) ml v 14.7 (0.98) ml; p < 0.001), and increase in mean (SEM) ejection fraction (65.7 (4.2)% v 43.6 (5.52)%; p < 0.001) and mean (SEM) rate constant of gall bladder emptying (-0.031/min v -0.020/min; p < 0.01) in patients who had been subjected to endoscopic sphincterotomy. Median nucleation time was significantly longer (17 days v 6 days; p < 0.006) in treated patients. There was a reduction in total mean (SEM) lipid concentrations (6.73 (0.32) g/dl v 7.72 (0.84) g/dl; p < 0.05), cholesterol (5.6 (1.5) mmol/l v 10.3 (2.23) mmol/l; p < 0.001) and CSI (0.72 (0.15) v 1.32 (0.31); p < 0.001). There was no significant change in mean (SEM) phospholipid (25.6 (3.5) mmol/l v 23.4 (6.28) mmol/l) and bile acid (93.7 (7.31) mmol/l v 105.07 (16.6) mmol/l) concentrations. CONCLUSIONS: After endoscopic sphincterotomy there was enhanced contractility of the gall bladder, accompanied by a prolongation of nucleation time and reduction in cholesterol saturation index.

Adult↗
PubMed2000

Patterns of gall-forming in Ossaea confertiflora (Melastomataceae) by Lopesia brasiliensis (Diptera: Cecidomyiidae) in an area of Atlantic Rainforest in southeastern Brazil.

Patterns of galling by the gall midge Lopesia brasiliensis (Diptera: Cecidomyiidae) were studied in Ossaea confertiflora (Melastomataceae) in an Atlantic forest site at Ilha Grande, RJ. Out of the 81 plants surveyed, 55 (67.9%) bore galls. The number of galls per galled individual ranged from 1 to 261 and 94.4% of the galls were in leaves. The number of galls per galled leaf varied from 1 to 25. Total gall number was positively correlated with plant height. Larger and more ramified plants tended to have a smaller percentage of their leaves with galls and a lower density of galls per leaf than smaller plants. Plants that were close to other individuals of the same species tended to have more galls per leaf than relatively isolated plants. The observed patterns may be linked to strategies of optimization in the use of resources (i.e. oviposition sites) and predation avoidance by the gall midges.

Animals↗
PubMed2000

Gallstones and gall bladder carcinoma.

BACKGROUND: The present study reviewed the occurrence of gall bladder carcinoma in patients who underwent a cholecystectomy for gallstone disease. METHODS: A retrospective study of demographical and clinical information for patients who underwent a cholecystectomy and operative cholangiogram for gallstones predominantly in three major hospitals located in the northern area of Melbourne was carried out. RESULTS: Gall bladder carcinomas were observed in 14 patients (3.2%; 95% confidence interval (CI): 1.8-5.3%) consisting of 11 women and three men of median age 78.5 years (interquartile range: 77-81) from a series of 439 patients with a male-to-female ratio of 1-2. The results of the present study show that primary carcinoma of the gall bladder in this descriptive retrospective cohort was always associated with single or multiple cholesterol gallstones that were impacting on the gall bladder wall. Cholesterol 'solitaire' gallstones were ovoid in shape with diameters > 3 cm along their longest axis, whereas multiple cholesterol gallstones varied in size and number from two or three large stones (1-2 cm), to numerous smaller stones (variable size to 0.5 cm). No patient with gall bladder carcinoma had either brown or black pigment gallstones. CONCLUSION: It is postulated that gall bladder carcinoma may be intimately associated with large or numerous cholesterol gallstones that in the first instance may interfere with the mechanical functioning of the gall bladder. The size as well as the number of gallstones present in the gall bladder may contribute significantly to the promotion of a gallstone filling defect of the gall bladder that may cause chronic mechanical damage to the gall bladder mucosa. The present report supports the hypothesis that gall bladder carcinoma is an age-dependent malignancy, present mostly in women, that may be intimately associated with long-standing benign gallstone disease of the gall bladder.

Adult↗
PubMed2001

Evolution of the gall wasp-host plant association.

Gall wasps, or cynipids, form the second largest radiation of galling insects with more than 1300 described species. According to current views, the first cynipids were phytophagous and developed in herb stems of the Asteraceae without modifying plant growth or development. The first galls were supposedly multichambered stem swellings, and subsequent trends involved increase in gall complexity and reduction in the number of larval chambers. Gall wasps also have many of the features believed to be characteristic for phytophagous insects radiating in parallel with their host plants. We tested these hypotheses by mapping characters onto a recent estimate of higher cynipid relationships from a morphology-based analysis of exemplar taxa, controlling for phylogenetic uncertainty using bootstrapping. Characters were also mapped onto a metatree including all gall wasps, assembled from phylogenetic analyses as well as recent classifications. The results contradict many of the current hypotheses. The first cynipids with extant descendants were not Asteraceae stem feeders but induced distinct single-chambered galls in reproductive organs of herbaceous Papaveraceae, or possibly Lamiaceae. There has been a general trend toward more complex galls but the herb-stem feeders evolved from ancestors inducing distinct galls and their larval chambers are best understood as cryptic galls. Woody hosts have been colonized only three times, making the apparently irreversible transition from herbs to woody hosts one of the most conservative features of the gall wasp-host plant association. The evolution of host plant preferences is characterized by colonization of preexisting host-plant lineages rather than by parallel cladogenesis. Cynipids are mono- or oligophagous and host-plant choice is strongly phylogenetically conserved. Yet, the few major host shifts have involved remarkably distantly related plants. Many shifts have been onto plant species already exploited by other gall wasps, suggesting that interspecific parasitism among cynipids facilitates colonization of novel host plants.

Animals↗
PubMed1992

Inhibition of human gall bladder mucus synthesis in patients undergoing cholecystectomy.

Hypersection of gall bladder mucus is associated with gall stone formation in animal models. Aspirin inhibits both mucus synthesis and secretion, prevents gall stone formation in animals and reduces gall stone recurrence in man after dissolution therapy. Mucus biosynthesis in human gall bladder mucosal explants is inhibited by aspirin in vitro. We have studied the effects of aspirin in vivo. Fifty five patients with functioning gall bladder and stones have been randomised, 27 to group 1 (aspirin EC 300 mg once daily for seven days before cholecystectomy) and 28 to group 2 (controls). Gall bladder bile composition was analysed and mucus synthesis rates measured using 3H-glucosamine incorporation into mucosal explants cultured for 24 hours. Patient age, sex, and gall bladder histology were similar in both groups. There were no differences in stone composition, gall bladder bile calcium concentration, cholesterol saturation and cholesterol nucleation time. The mean 3H-glucosamine incorporation in aspirin treated patients was 1347 fmol/g wet weight as compared with 2008 fmol/g wet weight in controls (95% confidence interval 222-1100, p<0.005, unpaired t test). This reduction in biosynthesis was associated with gall bladder bile mucus concentrations of 7.6 mg/ml in patients and 7.1 mg/ml in controls (ns). Treatment with aspirin led to a significant reduction in mucus biosynthesis by the gall bladder mucosa. This action is consistent with a role for aspirin in the prevention of gall stones.

Adult↗