Liver Size (liver + size)

Distribution by Scientific Domains


Selected Abstracts


Energy reserves during food deprivation and compensatory growth in juvenile roach: the importance of season and temperature

JOURNAL OF FISH BIOLOGY, Issue 1 2005
P. L. M. Van Dijk
The effect of 21 days of starvation, followed by a period of compensatory growth during refeeding, was studied in juvenile roach Rutilus rutilus during winter and summer, at 4, 20 and 27° C acclimation temperature and at a constant photoperiod (12L : 12D). Although light conditions were the same during summer and winter experiments and fish were acclimated to the same temperatures, there were significant differences in a range of variables between summer and winter. Generally winter fish were better prepared to face starvation than summer fish, especially when acclimated at a realistic cold season water temperature of 4° C. In winter, the cold acclimated fish had a two to three-fold larger relative liver size with an approximately double fractional lipid content, in comparison to summer animals at the same temperature. Their white muscle protein and glycogen concentration, but not their lipid content, were significantly higher. Season, independent of photoperiod or reproductive cycle, was therefore an important factor that determined the physiological status of the animal, and should generally be taken into account when fish are acclimated to different temperature regimes. There were no significant differences between seasons with respect to growth. Juvenile roach showed compensatory growth at all three acclimation temperatures with maximal rates of compensatory growth at 27° C. The replenishment of body energy stores, which were utilized during the starvation period, was responsible for the observed mass gain at 4° C. The contribution of the different energy resources (protein, glycogen and lipid) was dependent on acclimation temperature. In 20 and 27° C acclimated roach, the energetic needs during food deprivation were met by metabolizing white muscle energy stores. While the concentration of white muscle glycogen had decreased after the fasting period, the concentrations of white muscle lipid and protein remained more or less constant. The mobilization of protein and fat was revealed by the reduced size of the muscle after fasting, which was reflected in a decrease in condition factor. At 20° C, liver lipids and glycogen were mobilized, which caused a decrease both in the relative liver size and in the concentration of these substrates. Liver size was also decreased after fasting in the 4° C acclimated fish, but the substrate concentrations remained stable. This experimental group additionally utilized white muscle glycogen during food deprivation. Almost all measured variables were back at the control level within 7 days of refeeding. [source]


Stimulation of reproductive growth in rainbow trout (Oncorhynchus mykiss) following exposure to treated sewage effluent

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2006
Birgit Hoger
Abstract Rainbow trout (Oncorhynchus mykiss) were exposed to 1.5 and 15% v/v secondary treated sewage effluent for 32 weeks in flow-through mesocosms. The exposure encompassed the full period of reproductive development for rainbow trout. Trout did not show any evidence of a dose-dependent change in growth. Fish exposed to 15% effluent were the only group to show mortality (5%) over the duration of the experiment. Trout at the highest effluent concentration had significantly higher liver size than reference water fish. Both male and female trout in the 15% exposure group also exhibited significantly higher gonad weight than the reference group. In female trout, this gonad size increase could be explained by higher egg numbers. Female and male trout both displayed a significant increase in plasma 17,-estradiol levels after exposure to 15% effluent, while neither sex had dose-dependent differences in plasma testosterone. Male trout displayed elevated vitellogenin levels and reduced plasma 11-ketotestosterone concentration after exposure to 15% effluent. Chemical examination of steroidal compounds, including both estrogens and androgens, in the wastewater revealed that only estrone was detectable at a mean concentration of 4.5 ng/L. It is assumed that the effects observed in trout exposed to 15% effluent were consistent with stimulation of reproductive development due to very low levels of estrogens. Overall, long-term exposure to treated sewage effluent containing low levels of estrogen did not have significant negative implications for reproductive development in rainbow trout. [source]


Timing of exposure to a pulp and paper effluent influences the manifestation of reproductive effects in rainbow trout

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2002
Michael R. Van den Heuvel
Abstract Rainbow trout were exposed to a secondary treated, thermomechanical/bleached kraft pulp and paper effluent in 12,000-L, flow-through exposure tanks at an environmental research facility located at a pulp and paper mill in Kawerau, New Zealand. Trout (age, 2+ years) were obtained from a local hatchery and exposed either to upstream river water or a nominal concentration of 12% (v/v) effluent diluted in upstream river water. Three treatment groups were used: Effluent exposure that started approximately three months before gonadal growth (eight-month total exposure), effluent exposure that started approximately halfway through gonadal development (two-month total exposure), and trout exposed to reference water alone for the total duration of the experiment. Trout were sacrificed just before spawning; exposure, growth, and reproductive endpoints were assessed during and at the termination of the experiment. Reduction in growth was observed in both sexes in the eight-month treatment group relative to the river water reference treatment group. No differences were observed in condition factor or liver size in either treatment. Females in the eightmonth exposure group also had significantly lower ovary weight. The two-month exposure group showed no differences from the reference group in growth or somatic indices. Estradiol and testosterone were reduced in blood samples taken from the eight-month exposure group by four months into the experiment as compared to the reference treatment. Steroid and vitellogenin levels in individual female trout from this treatment were significantly correlated with gonadosomatic indices (GSI) measured at the termination of the experiment. The GSI was not correlated strongly or consistently with pregnenolone, nor were any treatment-related pregnenolone differences observed, indicating that the steroid hormone reductions likely were not related to cholesterol side-chain cleavage. Male trout showed significant induction of vitellogenin and lower 11-ketotestosterone during the experiment (only the eight-month group was examined), but this did not result in any significant differences in testes development. Thus, this study has shown an impact of pulp mill effluent exposure on the reproductive physiology of female trout that appeared to be hormonally mediated. Furthermore, the effect could only be manifest when the exposure was initiated before the start of gonad development. [source]


Themes of liver transplantation,

HEPATOLOGY, Issue 6 2010
Thomas E. Starzl
Liver transplantation was the product of five interlocking themes. These began in 1958-1959 with canine studies of then theoretical hepatotrophic molecules in portal venous blood (Theme I) and with the contemporaneous parallel development of liver and multivisceral transplant models (Theme II). Further Theme I investigations showed that insulin was the principal, although not the only, portal hepatotrophic factor. In addition to resolving long-standing controversies about the pathophysiology of portacaval shunt, the hepatotrophic studies blazed new trails in the regulation of liver size, function, and regeneration. They also targeted inborn metabolic errors (e.g., familial hyperlipoproteinemia) whose palliation by portal diversion presaged definitive correction with liver replacement. Clinical use of the Theme II transplant models depended on multiple drug immunosuppression (Theme III, Immunology), guided by an empirical algorithm of pattern recognition and therapeutic response. Successful liver replacement was first accomplished in 1967 with azathioprine, prednisone, and antilymphoid globulin. With this regimen, the world's longest surviving liver recipient is now 40 years postoperative. Incremental improvements in survival outcome occurred (Theme IV) when azathioprine was replaced by cyclosporine (1979), which was replaced in turn by tacrolimus (1989). However, the biologic meaning of alloengraftment remained enigmatic until multilineage donor leukocyte microchimerism was discovered in 1992 in long-surviving organ recipients. Seminal mechanisms were then identified (clonal exhaustion-deletion and immune ignorance) that linked organ engraftment and the acquired tolerance of bone marrow transplantation and eventually clarified the relationship of transplantation immunology to the immunology of infections, neoplasms, and autoimmune disorders. With this insight, better strategies of immunosuppression have evolved. As liver and other kinds of organ transplantation became accepted as healthcare standards, the ethical, legal, equity, and the other humanism issues of Theme V have been resolved less conclusively than the medical-scientific problems of Themes I-IV. HEPATOLOGY 2010 [source]


Energy reserves during food deprivation and compensatory growth in juvenile roach: the importance of season and temperature

JOURNAL OF FISH BIOLOGY, Issue 1 2005
P. L. M. Van Dijk
The effect of 21 days of starvation, followed by a period of compensatory growth during refeeding, was studied in juvenile roach Rutilus rutilus during winter and summer, at 4, 20 and 27° C acclimation temperature and at a constant photoperiod (12L : 12D). Although light conditions were the same during summer and winter experiments and fish were acclimated to the same temperatures, there were significant differences in a range of variables between summer and winter. Generally winter fish were better prepared to face starvation than summer fish, especially when acclimated at a realistic cold season water temperature of 4° C. In winter, the cold acclimated fish had a two to three-fold larger relative liver size with an approximately double fractional lipid content, in comparison to summer animals at the same temperature. Their white muscle protein and glycogen concentration, but not their lipid content, were significantly higher. Season, independent of photoperiod or reproductive cycle, was therefore an important factor that determined the physiological status of the animal, and should generally be taken into account when fish are acclimated to different temperature regimes. There were no significant differences between seasons with respect to growth. Juvenile roach showed compensatory growth at all three acclimation temperatures with maximal rates of compensatory growth at 27° C. The replenishment of body energy stores, which were utilized during the starvation period, was responsible for the observed mass gain at 4° C. The contribution of the different energy resources (protein, glycogen and lipid) was dependent on acclimation temperature. In 20 and 27° C acclimated roach, the energetic needs during food deprivation were met by metabolizing white muscle energy stores. While the concentration of white muscle glycogen had decreased after the fasting period, the concentrations of white muscle lipid and protein remained more or less constant. The mobilization of protein and fat was revealed by the reduced size of the muscle after fasting, which was reflected in a decrease in condition factor. At 20° C, liver lipids and glycogen were mobilized, which caused a decrease both in the relative liver size and in the concentration of these substrates. Liver size was also decreased after fasting in the 4° C acclimated fish, but the substrate concentrations remained stable. This experimental group additionally utilized white muscle glycogen during food deprivation. Almost all measured variables were back at the control level within 7 days of refeeding. [source]


Hepatic Volume Measurements in Dogs with Extrahepatic Congenital Portosystemic Shunts before and after Surgical Attenuation

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
A. Kummeling
Background: In dogs with congenital portosystemic shunts (CPSS), the ability of the hypoplastic liver to grow is considered important for recovery after surgical shunt attenuation. Objectives: This study investigated hepatic growth after extrahepatic shunt attenuation in dogs using magnetic resonance imaging (MRI) and computed tomography (CT). Animals: Ten client-owned dogs with single extrahepatic CPSS. Methods: Abdominal MRI, CT, or both were performed before and 8 days, 1, and 2 months after shunt attenuation. Liver volumes were calculated from the areas of the MRI or CT images. Results: Before surgery, median liver volume was 18.2 cm3/kg body weight. Liver volume increased significantly after surgery. Growth was highest between days 0 and 8 and decreased afterward. Median liver volume was 28.8 cm3/kg at 2 months after attenuation. No significant differences in growth were found between dogs with complete or partial shunt closure or between dogs with complete or incomplete metabolic recovery. Volumes measured from consecutively performed MRI and CT images correlated well (r= 0.980), but volumes from MRI images were significantly larger than volumes from CT images (6.8%; P= .008). Conclusion and Clinical Importance: After shunt attenuation, rapid normalization of liver size was observed. Hepatic growth was not decreased in dogs after partial closure of CPSS or in dogs with subclinical, persistent shunting 2 months after surgery. CT is the preferred imaging method for volumetric estimation because of speed. [source]


Liver regeneration after adult living donor and deceased donor split-liver transplants

LIVER TRANSPLANTATION, Issue 3 2004
Abhinav Humar
As the number of living donor (LD) and deceased donor (DD) split-liver transplants (SLTs) have increased over the last 5 years, so too has the interest in liver regeneration after such partial-liver transplants. We looked at liver regeneration, as measured by computed tomography (CT) volumetrics, to see if there were significant differences among LDs, right-lobe LD recipients, and SLT recipients. We measured liver volume at 3 months postoperatively by using CT, and we compared the result to the patient's ideal liver volume (ILV), which was calculated using a standard equation. The study group consisted of 70 adult patients who either had donated their right lobe for LD transplants (n = 24) or had undergone a partial-liver transplant (right-lobe LD transplants, n = 24; right-lobe SLTs, n = 11; left-lobe SLTs, n = 11). DD (vs. LDs) were younger (P < 0.01), were heavier (P = 0.06), and had longer ischemic times (P < 0.01). At 3 months postoperatively, LDs had attained 78.6% of their ILV, less than the percentage for right-lobe LD recipients (103.9%; P = 0.0002), right-lobe SLT recipients (113.6%; P = 0.01), and left-lobe SLT recipients (119.7%; P = 0.0006). When liver size at the third postoperative month was compared with the liver size immediately postoperatively, LDs had a 1.85-fold increase. This was smaller than the increase seen in right-lobe LD recipients (2.08-fold), right-lobe SLT recipients (2.17-fold), and left-lobe SLT recipients (2.52-fold). In conclusion, liver regeneration, as measured by CT volume, seems to be greatest in SLT recipients. LD recipients seem to have greater liver growth than their donors. The reason for this remains unclear. (Liver Transpl 2004;10:374,378.) [source]


Outcome of the use of pediatric donor livers in adult recipients

LIVER TRANSPLANTATION, Issue 1 2001
Motohiko Yasutomi
The prolonged waiting time caused by the lack of donor livers leads to an increasing number of terminally ill patients waiting for lifesaving liver transplantation. To rescue these patients, transplant programs are accepting donor organs from the expanded donor pool, using donors of increasingly older age, as well as from the pediatric age group, often despite significant mismatch in liver size. We investigated the outcome of 102 consecutive liver transplantations using pediatric donor livers in adult recipients. One-year graft survival using donors aged 12 years or younger (group 1, n = 14) and donors aged 12 to 18 years (group 2, n = 88) was compared. In addition, risk factors for graft loss and vascular complications were analyzed. The 1-year graft survival rate in adult transplant recipients in group 1 was 64.3% compared with 87.5% in those in group 2 (P = .015). The main cause of graft loss was arterial complications, occurring in 5 of 16 transplant recipients (31.3%). Major risk factors for graft loss and vascular complications were related to the size of the donor: age, height and weight, body surface area of donor and recipient, and warm ischemic time. We conclude that the outcome of small pediatric donor livers in adult recipients is poor, mainly because of the increased incidence of arterial complications. When a pediatric donor is used in an adult recipient, ischemic time should be kept to a minimum and anticoagulative therapy should be administered in the immediate postoperative period to avoid arterial complications. However, because small pediatric donors are the only source of lifesaving organs for the infant recipient, the use of small pediatric donor livers in adults should be avoided. [source]


Highly symptomatic adult polycystic liver disease: options and results of surgical management

ANZ JOURNAL OF SURGERY, Issue 8 2004
Yu Meng Tan
Background: The majority of patients afflicted with adult polycystic liver disease (APLD) are asymptomatic. For those who are symptomatic, there are a variety of treatment procedures that have been proposed but these lack verification through long-term studies with respect to safety and long-term effectiveness. Choice of surgical procedure is related to the severity of APLD and morphology of the cysts within the liver. The aim of the present study was to analyse the immediate and long-term results of fenestration and combined resection,fenestration at Singapore General Hospital. Methods: A retrospective analysis of clinical, operative, imaging and follow-up data was carried out for 12 patients (10 women and two men) with symptomatic APLD who underwent surgery from January 1992 to December 2000. The primary outcome measures assessed were postoperative alleviation of symptoms, performance status, complications, mortality and long-term recurrence of symptoms. Results: Nine patients underwent 12 fenestration procedures and three patients had combined resection,fenestration. Fenestration was carried out for eight of nine patients with a dominant cyst morphology and combination resection,fenestration was carried out for those three patients with diffuse cyst morphology. There was no operative mortality and all patients were discharged from hospital free of their preoperative symptoms. Overall morbidity rate was 58%. The mean follow up for the present cohort was 29.3 months. Only two patients had recurrence of symptoms. One patient with dominant cyst morphology who underwent laparoscopic fenestration had recurrence at 26 and 43 months but this was successfully treated finally with open fenestration. The other patient had diffuse cyst morphology and was treated with fenestration for recurrent cyst infection that recurred 1 month postoperatively. This required subsequent intravenous antibiotics and percutaneous drainage for resolution of symptoms. Conclusion: Treatment for symptomatic APLD should be based on the morphology of the liver cysts. Fenestration is a safe and acceptable procedure for patients with a dominant cyst pattern where liver size can be reduced after the cysts collapse. A combination of resection,fenestration is suitable for those with a diffuse cyst pattern where grossly affected segments are resected in combination with fenestration to allow for reduction in liver size. [source]


Effect of feed composition and feeding frequency on growth, feed utilization and nutrient retention in juvenile Atlantic cod, Gadus morhua L.

AQUACULTURE NUTRITION, Issue 6 2004
G. Rosenlund
Abstract Juvenile Atlantic cod (Gadus morhua) were fed extruded feeds formulated to contain 360,660 g kg,1 protein, 80,280 g kg,1 lipid and 80,180 g kg,1 starch at feeding frequencies of either once per day or every second day to satiation. The trial was conducted at 8 °C and lasted for 28 weeks during which fish were weighed five times at regular intervals. Sampling for proximate analysis was performed at the start, after 12 weeks and at the end of the trial. Fish grew from an average weight of 192 g to between 750 and 866 g, with growth being negatively affected by low dietary protein concentration. High dietary starch concentrations had some negative effects on growth, whereas changes in dietary fat concentration had no significant effect on growth. Liver indices (at the end of the experiment) varied between 80 and 170 g kg,1, and there was a negative correlation between the ratio of protein to fat and liver index. Feed conversion ratio (FCR) ranged between 0.74 and 0.88, and feed utilization improved with increasing concentrations of dietary protein and fat. Increasing dietary starch concentrations resulted in poorer feed utilization. To achieve good growth and protein retention, and avoid excessive liver size in juvenile cod, feeds should contain 500,600 g kg,1 crude protein, 130,200 g kg,1 lipid and <150 g kg,1 starch. [source]


Hypervitaminosis A in first-feeding fry of the Atlantic salmon (Salmo salar L.)

AQUACULTURE NUTRITION, Issue 1 2002
R. ØRNSRUD
Atlantic salmon fry were reared on a fishmeal based diet with increasing levels of vitamin A (VA) (6, 122 and 938 mg retinol kg,1 dry feed) from startfeeding and for 14 weeks. Signs of VA stress, such as reduced fat stores, liver size and growth, were found for groups receiving 122 and 938 mg retinol kg,1. Signs of vitamin A toxicity, such as increased mortality, abnormal vertebral growth, and reduced growth, were found for groups receiving 938 mg retinol kg,1. These results suggest that excess VA in the early life stages of Atlantic salmon is deleterious for normal development. [source]