Amoebic gill disease increases energy requirements and decreases hypoxia tolerance in Atlantic salmon (Salmo salar) smolts.

Globally, Atlantic salmon (Salmo salar Linnaeus) aquaculture is now routinely affected by amoebic gill disease (AGD; Neoparamoeba perurans). The disease proliferates throughout the summer and is implicated in decreasing tolerance of salmon to environmental perturbations, yet little empirical evidence exists to support these observations. Using salmon acclimated to 15 or 19 °C, our aim was to determine the effects of clinically light-moderate (industry-relevant) AGD on metabolism (MO2rest and MO2max), aerobic scope (MO2max - MO2rest), excess post-exercise oxygen consumption (EPOC), and hypoxia tolerance. An increase in MO2rest (~8% and ~ 13% increase within the 15 and 19 °C acclimation groups, respectively) with increasing disease signs demonstrated an increase in baseline energy requirements as the disease progressed. Conversely, MO2max remained stable at both temperatures (~364 mg O2 kg-1 h-1), resulting in a decline in aerobic scope by 13 and 19% in the 15 and 19 °C groups, respectively. There was evidence of a decrease in hypoxia tolerance as the dissolved oxygen concentrations at loss of equilibrium increased by ~8% with more severe lesion coverage of the gills. These results suggest an increase in basal energy requirements and reduction in hypoxia tolerance as AGD proliferates, lending support to the idea that AGD reduces environmental tolerance. However, the lack of an effect of acclimation temperature indicates that the temperature-disease interaction may be more complicated than currently thought.

Comparison of bacterial diversity and distribution on the gills of Atlantic salmon (Salmo salar L.): an evaluation of sampling techniques.

AIMS: Assess bacterial diversity and richness in mucus samples from the gills of Atlantic salmon in comparison to preserved or fixed gill filament tissues. Ascertain whether bacterial diversity and richness are homogeneous upon different arches of the gill basket. METHODS AND RESULTS: Bacterial communities contained within gill mucus were profiled using 16S rRNA gene sequencing. No significant difference in taxa richness, alpha (P > 0·05) or beta diversity indices (P > 0·05) were found between the bacterial communities of RNAlater preserved gill tissues and swab-bound mucus. A trend of lower richness and diversity indices were observed in bacterial communities from posterior hemibranchs. CONCLUSIONS: Non-lethal swab sampling of gill mucus provides a robust representation of bacterial communities externally upon the gills. Bacterial communities from the fourth arch appeared to be the least representative overall. SIGNIFICANCE AND IMPACT OF THE STUDY: The external mucosal barriers of teleost fish (e.g. gill surface) play a vital role as a primary defence line against infection. While research effort on the role of microbial communities on health and immunity of aquaculture species continues, the collection and sampling processes to obtain these data require evaluation so methodologies are consistently applied across future studies that aim to evaluate the composition of branchial microbiomes.

Concurrence of lower jaw skeletal anomalies in triploid Atlantic salmon (Salmo salar L.) and the effect on growth in freshwater.

Triploid Atlantic salmon populations are associated with higher prevalence of lower jaw skeletal anomalies affecting fish performance, welfare and value deleteriously. Anomalous lower jaw can be curved downward (LJD), shortened (SJ) or misaligned (MA). Two separate groups of triploid Atlantic salmon (~12 g) with either normal lower jaw (NOR) or SJ were visually assessed four times over three months for presence and concurrence of jaw anomalies (with severity classified) and opercular shortening to understand the relatedness of these anomalous developmental processes. The prevalence of jaw anomalies increased in both groups over time (NOR group - SJ, LJD and MA combined 0-24.5%; SJ group - LJD and MA combined 17-31%). SJ and LJD occurred both independently and concurrently whereas MA exclusively concurred with them. All three anomalies could be concurrent. Severity of both LJD and SJ increased in the SJ group only. Opercular shortening recovery was observed in both groups but at a slower rate in the SJ group. The SJ group specific growth rate (SGR) was significantly (P < 0.05) lower than the NOR group. This study demonstrated the concurrence of SJ, LJD and MA and showed possible deleterious consequences deriving from the conditions.

Skeletal anomaly assessment in diploid and triploid juvenile Atlantic salmon (Salmo salar L.) and the effect of temperature in freshwater.

Triploid Atlantic salmon tend to develop a higher prevalence of skeletal anomalies. This tendency may be exacerbated by an inadequate rearing temperature. Early juvenile all-female diploid and triploid Atlantic salmon were screened for skeletal anomalies in consecutive experiments to include two size ranges: the first tested the effect of ploidy (0.2-8 g) and the second the effect of ploidy, temperature (14 °C and 18 °C) and their interaction (8-60 g). The first experiment showed that ploidy had no effect on skeletal anomaly prevalence. A high prevalence of opercular shortening was observed (average prevalence in both ploidies 85.8%) and short lower jaws were common (highest prevalence observed 11.3%). In the second experiment, ploidy, but not temperature, affected the prevalence of short lower jaw (diploids > triploids) and lower jaw deformity (triploids > diploids, highest prevalence observed 11.1% triploids and 2.7% diploids) with a trend indicating a possible developmental link between the two jaw anomalies in triploids. A radiological assessment (n = 240 individuals) showed that at both temperatures triploids had a significantly (P < 0.05) lower number of vertebrae and higher prevalence of deformed individuals. These findings (second experiment) suggest ploidy was more influential than temperature in this study.

Changes in the interbranchial lymphoid tissue of Atlantic salmon (Salmo salar) affected by amoebic gill disease.

The interbranchial lymphoid tissue (ILT) was recently described in the gills of salmonids. This study examined changes in the ILT during a parasitic infection in marine environment, using amoebic gill disease (AGD) as a model. Atlantic salmon (Salmo salar) experimentally infected with Neoparamoeba perurans were sampled at 0, 3, 7, 14 and 28 days post challenge. Transversal sections of three areas of the gills (dorsal, medial and ventral) were histologically assessed for morphological and cellular changes. AGD induced morphological changes and a cellular response in the ILT of affected fish. These changes included a significant increase in the ILT surface area in fish 28 days after AGD challenge, compared to control fish at the same time point. The length of the ILT increased significantly 28 days post exposure in the dorsal area of the gill arch in the fish affected by AGD. The lymphocyte density of the ILT increased after AGD challenge, peaking at 7 days post exposure; however, by 28 days post exposure, a reduction of lymphocyte density to values close to pre-infection levels was observed. PCNA immunostaining revealed that epithelial hyperplasia was the most likely factor contributing to the ILT enlargement in the affected fish.

Preliminary success using hydrogen peroxide to treat Atlantic salmon, Salmo salar L., affected with experimentally induced amoebic gill disease (AGD).

Currently, the only effective and commercially used treatment for amoebic gill disease (AGD) in farmed Tasmanian Atlantic salmon is freshwater bathing. Hydrogen peroxide (H2O2), commonly used throughout the aquaculture industry for a range of topical skin and gill infections, was trialled in vitro and in vivo to ascertain its potential as an alternative treatment against AGD. Under in vitro conditions, trophozoites of Neoparamoeba perurans were exposed to three concentrations of H2O2 in sea water (500, 1000 and 1500 mg L⁻¹) over four durations (10, 20, 30 and 60 min) each at two temperatures (12 and 18 °C). Trophozoite viability was assessed immediately post-exposure and after 24 h. A concentration/duration combination of 1000 mg L⁻¹ for >10 min demonstrated potent amoebicidal activity. Subsequently, Atlantic salmon mildly affected with experimentally induced AGD were treated with H2O2 at 12 and 18 °C for 15 min at 1250 mg L⁻¹ and their re-infection rate was compared to freshwater-treated fish over 21 days. Significant differences in the percentage of filaments affected with hyperplastic lesions (in association with amoebae) and plasma osmolality were noted between treatment groups immediately post-bath. However, the results were largely equivocal in terms of disease resolution over a 3-week period following treatment. These data suggest that H2O2 treatment in sea water successfully ameliorated a clinically light case of AGD under laboratory conditions.

Experimental evidence of early-time saturation of the ion-Weibel instability in counterstreaming plasmas of CH, Al, and Cu.

The collisionless ion-Weibel instability is a leading candidate mechanism for the formation of collisionless shocks in many astrophysical systems, where the typical distance between particle collisions is much larger than the system size. Multiple laboratory experiments aimed at studying this process utilize laser-driven (I≳10^{15} W/cm^{2}), counterstreaming plasma flows (V≲2000 km/s) to create conditions unstable to Weibel-filamentation and growth. This technique intrinsically produces temporally varying plasma conditions at the midplane of the interaction where Weibel-driven B fields are generated and studied. Experiments discussed herein demonstrate robust formation of Weibel-driven B fields under multiple plasma conditions using CH, Al, and Cu plasmas. Linear theory based on benchmarked radiation-hydrodynamic FLASH calculations is compared with Fourier analyses of proton images taken ∼5-6 linear growth times into the evolution. The new analyses presented here indicate that the low-density, high-velocity plasma-conditions present during the first linear-growth time (∼300-500 ps) sets the spectral characteristics of Weibel filaments during the entire evolution. It is shown that the dominant wavelength (∼300µm) at saturation persists well into the nonlinear phase, consistent with theory under these experimental conditions. However, estimates of B-field strength, while difficult to determine accurately due to the path-integrated nature of proton imaging, are shown to be in the ∼10-30 T range, an order of magnitude above the expected saturation limit in homogenous plamas but consistent with enhanced B fields in the midplane due to temporally varying plasma conditions in experiments.

Neoparamoeba perurans n. sp., an agent of amoebic gill disease of Atlantic salmon (Salmo salar).

Amoebic gill disease (AGD) is a potentially fatal disease of some marine fish. Two amphizoic amoebae Neoparamoeba pemaquidensis and Neoparamoeba branchiphila have been cultured from AGD-affected fish, yet it is not known if one or both are aetiological agents. Here, we PCR amplified the 18S rRNA gene of non-cultured, gill-derived (NCGD) amoebae from AGD-affected Atlantic salmon (Salmo salar) using N. pemaquidensis and N. branchiphila-specific oligonucleotides. Variability in PCR amplification led to comparisons of 18S rRNA and 28S rRNA gene sequences from NCGD and clonal cultured, gill-derived (CCGD) N. pemaquidensis and N. branchiphila. Phylogenetic analyses inferred from either 18S or 28S rRNA gene sequences unambiguously segregated a lineage consisting of NCGD amoebae from other members of the genus Neoparamoeba. Species-specific oligonucleotide probes that hybridise 18S rRNA were designed, validated and used to probe gill tissue from AGD-affected Atlantic salmon. The NCGD amoebae-specific probe bound AGD-associated amoebae while neither N. pemaquidensis nor N. branchiphila were associated with AGD-lesions. Together, these data indicate that NCGD amoebae are a new species, designated Neoparamoeba perurans n.sp. and this is the predominant aetiological agent of AGD of Atlantic salmon cultured in Tasmania, Australia.

Does opening the peritoneum at the time of renal transplanation prevent lymphocele formation?

BACKGROUND: The occurrence of lymphocele formation following renal transplantation is variable, and the optimal approach to treatment remains undefined. Opening the peritoneum at the time of transplantation is one method of decreasing the incidence of lymphocele formation. The purpose of this study was to determine whether creating a peritoneal window at the time of transplantation decreases the incidence of lymphocele formation. METHODS: We performed a retrospective review of renal transplants conducted at our institution between 2002 and 2004. Records were reviewed to obtain details regarding opening of the peritoneum at the time of transplant and occurrence of lymphocele. Every patient underwent routine ultrasound imaging in the peri-operative period. Graft dysfunction secondary to the lymphocele was the primary indication for intervention. Data were analyzed by chi-square. RESULTS: During the initial transplant the peritoneum was opened in 35% of patients. The overall incidence of fluid collections, identified by ultrasound, was 24%. Opening the peritoneum did not decrease the incidence of lymphocele. However, more patients with a closed peritoneum required an intervention for a symptomatic lymphocele. In the 11 patients with an open peritoneum and a fluid collection, only one required an intervention. In patients whose peritoneum was left intact, 24% of fluid collections required intervention. Graft survival was equivalent. CONCLUSION: Creating a peritoneal window at the time of transplantation did not decrease the overall incidence of postoperative fluid collections. However, forming a peritoneal window at the time of transplantation did decrease the incidence of symptomatic lymphocele.

Syngeneic pancreatic islet transplantation reverses endothelial dysfunction in experimental diabetes.

Diabetes is known to cause impaired endothelium-dependent relaxation of blood vessels. The purpose of this study was to determine whether this endothelial dysfunction is a permanent defect or is reversible after acute arginine supplementation in vitro or by surgical intervention in vivo using syngeneic pancreatic islet transplantation. Lewis rats were injected with streptozotocin to induce diabetes and were studied either 8 or 12 weeks later. Another group received syngeneic islets via intraportal injection at 8 weeks of diabetes and were allowed to become euglycemic for 4 weeks before study. Thoracic aortic rings were tethered in isolated muscle baths, contracted with a submaximal concentration of norepinephrine, and challenged with either the endothelium-dependent vasodilator acetylcholine or the endothelium-independent vasodilator nitroglycerin. Relaxation to acetylcholine (but not nitroglycerin) was reduced in both 8- and 12-week diabetic rings compared with age-matched control rings. Preincubation of diabetic rings in vitro with L-arginine (but not D-arginine) restored relaxation to acetylcholine to normal to rings from 8-week but not 12-week diabetic animals. Plasma basic amino acids (arginine, lysine, and histidine) were reduced by diabetes, whereas other neutral or acidic amino acids were unchanged (phenylalanine, proline, and glutamate), reduced (serine, cysteine, threonine, tyrosine, tryptophan, and aspartate), or elevated (isoleucine, leucine, and valine). Islet transplantation restored to normal the changes in plasma amino acids. Elevation in blood glucose and total glycosylated hemoglobin in diabetic animals was normalized after islet transplantation. Furthermore, islet transplantation completely restored the defective endothelium-dependent relaxation to acetylcholine in diabetic rings.(ABSTRACT TRUNCATED AT 250 WORDS)

Peroxidative stress in diabetic blood vessels. Reversal by pancreatic islet transplantation.

Diabetic complications are believed to arise, in part, through an increase in oxidative stress. We characterized antioxidant status in vascular tissue in untreated diabetic rats and in diabetic rats rendered euglycemic by pancreatic islet transplantation. Three key endogenous antioxidant enzymes (e.g., superoxide dismutase, catalase, and glutathione peroxidase) were measured. Sprague-Dawley rats with streptozotocin-induced diabetes were killed after 8 weeks of untreated hyperglycemia and compared with age-matched controls. Eight weeks of untreated diabetes resulted in a significant increase of tissue catalase in aorta, iliac artery, and femoral artery as compared with controls. No significant changes in either superoxide dismutase or glutathione peroxidase were observed in aorta, iliac artery, or femoral artery of diabetic animals. This increase in catalase in diabetic vascular tissue suggests increased oxidative stress due to chronic exposure to H2O2 in vivo. To assess the impact of islet transplantation on oxidative stress in vascular tissue, inbred Lewis strain rats were rendered diabetic with streptozotocin. After 8 weeks of untreated diabetes, rats received an intraportal islet isograft and were monitored for 4 subsequent weeks of euglycemia. Islet transplantation improved weight gain and normalized blood glucose and total glycosylated hemoglobin. While catalase was significantly increased in aorta and iliac artery at 8 and 12 weeks of diabetes, vascular catalase was restored to normal by islet transplantation. These data suggest that islet transplantation is an effective treatment strategy to minimize increased oxidative stress in diabetic vasculature.

Cultured gill-derived Neoparamoeba pemaquidensis fails to elicit amoebic gill disease (AGD) in Atlantic salmon Salmo salar.

Amoebic gill disease (AGD) affects the culture of Atlantic salmon Salmo salar in the southeast of Tasmania. The disease is characterised by the presence of epizoic Neoparamoeba spp. in association with hyperplastic gill tissue. Gill-associated amoebae trophozoites were positively selected by plastic adherence for culture in seawater, where they proliferated using heat-killed E. coli as a nutrient source. One isolate of gill-harvested amoebae designated NP251002 was morphologically consistent to N. pemaquidensis under light, fluorescence and transmission electron microscopy. Rabbit anti-N. pemaquidensis antiserum bound to NP251002, and N. pemaquidensis small subunit (SSU) ribosomal DNA (18S rDNA) was detected in NP251002 genomic DNA preparations using PCR. A high degree of similarity in the alignment of the NP251002 18S rDNA PCR amplicon sequence with reference isolates of N. pemaquidensis suggested conspecificity. While short-term culture (72 h) of gill-harvested amoebae does not affect the capacity of amoebae to induce AGD, Atlantic salmon challenged with NP251002 after the trophozoites had been 34 and 98 d in culture exhibited neither gross nor histological evidence of AGD. It is not known if NP251002 were avirulent at the time of isolation, had down-regulated putative virulence factors or virulence was inhibited by the culture conditions. Therefore, the time in culture could be a limiting factor in maintaining virulence using the culture technique described here.

Impact of restriction of placental and fetal growth on expression of 11beta-hydroxysteroid dehydrogenase type 1 and type 2 messenger ribonucleic acid in the liver, kidney, and adrenal of the sheep fetus.

We have investigated the effects of fetal growth restriction, induced by restriction of placental growth and function (PR), on 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD-1) and 11betaHSD-2 messenger RNA (mRNA) expression in fetal tissues in the sheep, using Northern blot analysis. Fetal liver, kidney, and adrenals were collected from normally grown fetuses at 90 days (n = 6), 125 days (n = 6), and 141-145 days (n = 7) and from PR fetuses at 141-145 days (n = 6). Expression of 11betaHSD-1 mRNA in the fetal liver increased significantly between 125 days (7.4+/-0.8) and 141-145 days gestation (27+/-5.3). There was also an approximately 2-fold increase in the ratio of 11betaHSD-1 mRNA/18S rRNA expression in the PR group (53.8+/-7.9) compared with that in control animals at 141-145 days gestation. There was a significant decrease in 11betaHSD-2 mRNA in fetal adrenals between 125 days (41.6+/-2.4) and 141-145 days (26.7+/-1.1) gestation, but there was no effect of PR on the expression of adrenal 11betaHSD-2 mRNA. 11betaHSD-2 mRNA expression in the fetal kidney increased between 90 days (16.8+/-1.7) and 141-145 days gestation (31.7+/-4.3), but there was no effect of PR on the levels of 11betaHSD-2 mRNA in the fetal kidney. In summary, 11betaHSD-2 mRNA is differentially regulated in the fetal adrenal and kidney in the sheep fetus during late gestation. There is also a specific increase in the expression of 11betaHSD-1 mRNA in the liver of growth-restricted fetuses in late gestation. This suggests that there is increased hepatic exposure to cortisol in the growth-restricted fetus, which may be important in the reprogramming of hepatic physiology that occurs after growth restriction in utero.

Electron spin resonance analysis of heme-nitrosyl and reduced iron-sulfur centered complexes in allogeneic, heterotopic cardiac transplants: effects of treatment with pyrrolidine dithiocarbamate.

Inhibition of inducible nitric oxide synthase (iNOS) prolongs allograft survival suggesting a role for nitric oxide (.NO) in allograft rejection. Induction of iNOS is regulated by the oxidant-sensitive, nuclear factor kappa B (NF-kappaB) in many cell types. In the present study using electron spin resonance (ESR) spectroscopy, we evaluated whether pyrrolidine dithiocarbamate (PDTC), a metal chelator and antioxidant, might limit .NO production during the development of rejection in cardiac allografts. We performed either isogeneic (Lewis to Lewis) or allogeneic (Wistar-Furth to Lewis) heterotopic abdominal cardiac transplantation. Allograft recipients received daily injections of PDTC or aminoguanidine (a known inhibitor of iNOS). At postoperative days 4 or 6, grafted and native hearts of transplant recipients were flushed with cardioplegic solution to remove blood contamination. ESR data of allografts revealed a triplet nitrogen signal (aN=17.5 G) and centered at g=2.012 and an additional broad signal at g=2.08. This signal was not seen in either isografts or native hearts of either isograft or allograft recipients. Based upon these parameters, these signals are attributed to nitrosomyoglobin. This signal was inhibited by treatment with aminoguanidine or PDTC. Under these conditions, PDTC also prolonged graft survival from 6.6+/-0.2 to 11.7+/-0.3 days. Thus, it is conceivable that nitrosylmyoglobin formation precedes rejection in cardiac allografts and inhibition of nitrosomyoglobin with agents such as PDTC contribute to improved graft survival.

Antioxidant treatment inhibits activation of myocardial nuclear factor kappa B and inhibits nitrosylation of myocardial heme protein in cardiac transplant rejection.

Nitric oxide production via inducible nitric oxide synthase (iNOS) is believed to play a role in cardiac allograft rejection. Previously, we showed that antioxidants can significantly prolong cardiac graft survival, but the nature of this protection is unknown. In the present study, we examined the protective effect of another antioxidant, dimethylthiourea (DMTU), in a model of cardiac allograft rejection. Specifically, we hypothesized that DMTU would prolong graft survival and decrease activation of nuclear factor-kappa B (NF-kappa B), an important redox-sensitive transcription factor necessary for iNOS gene expression. NF-kappa B was activated by twofold as early as postoperative day 2 in allografts. NF-kappa B activation in allografts progressed to a peak of ninefold by postoperative day and remained increased until postoperative day 6. No activation of NF-kappa B was observed in isografts for comparable time periods. Treatment with DMTU resulted in a significant prolongation of graft survival. This beneficial effect was associated with diminished activation of myocardial NF-kappa B. Treatment with DMTU also resulted in decreased formation of iron-nitrosylprotein complexes as evidenced by electron paramagnetic resonance spectroscopy. These studies provide evidence that reactive oxygen plays a significant role in signal transduction for activation via the transcription factor, NF-kappa B, thereby modulating distal actions and consequences of iNOS-derived nitric oxide.

Enisoprost in renal transplantation. The Enisoprost Renal Transplant Study Group.

Prostaglandins of the E-series (PGE) mediate a wide variety of physiologic processes and have been shown to have regulatory roles in cell immunity. Previous animal and human trials have shown lower incidence of acute rejection when prostaglandins are administered in conjunction with standard immunosuppressives. This study evaluated the effects of the PGE analogue, enisoprost (EP), in a multicenter (39 centers) prospective, randomized, double-blind trial in 374 patients undergoing renal transplantation. Groups were placebo, enisoprost 50 micrograms p.o. q.i.d. (EP-50 micrograms), and enisoprost 100 micrograms p.o. q.i.d. (EP-100 micrograms). Patients received cyclosporine, azathioprine, corticosteroids, and Minnesota antilymphocyte globulin or OKT3 according to each center's protocol. Prophylactic antibody therapy (MALG or OKT3) was not randomized. Two hundred fifty-five patients completed the 8-week study period. Of the 119 patients who were withdrawn, 73 did so because of an adverse event. Rejection episodes occurred in 98 of 374 patients (26%). There was no statistically significant difference in the incidence of rejection between placebo- and EP-treated patients (P = 0.782). There was no significant difference in episodes of cyclosporine nephrotoxicity between placebo- and EP-treatment groups (P = 0.883). There was also no difference between incidence of acute tubular necrosis, duration of initial hospitalization, or need for rehospitalization between placebo- and EP-treated groups. Administration of EP was associated with frequent adverse events including elevation of body temperature, dyspepsia, and diarrhea. Antibody-treated patients had a higher percentage of black recipients, higher mean body weight, greater cold ischemic times, fewer living-related donors, and higher panel reactivity. Patients not receiving antibody prophylaxis were better matched immunologically than those receiving either MALG or OKT3. Despite these immunologic differences, there was no significant difference in the incidence of rejection in patients who did or did not receive antibody prophylaxis. Cyclosporine toxicity was more common in MALG-treated patients (P = 0.02). Renal function was worse in antibody-treated patients. There was no detectable effect of enisoprost on the incidence of acute rejection, renal function, or hospitalization in a multicenter prospective, randomized, double-blind trial in 374 patients undergoing renal transplantation.

Delayed cardiac allograft rejection due to combined cyclosporine and antioxidant therapy.

The effectors of cell death in allograft rejection are poorly understood. Oxygen derived free radicals (ODFR) may participate in graft destruction. We examined the impact of the antioxidants ascorbic acid (AA) and alpha-tocopherol (AT) with low dose CsA on rat cardiac allograft survival. Lewis rats that had undergone heterotopic abdominal cardiac transplantation with Wistar-Furth allografts (day 0) were divided into 6 groups. Group 1 was the control group; groups 2 and 3 received AA (1200 mg/kg), and groups 4 and 5 received AT (800 IU/kg) by gavage daily until rejection. Groups 3, 5, and 6 were given CsA (2.5 mg/kg i.m.) days 1-15. Allograft rejection times (in days) were 7.7 +/- 1, 10.3 +/- 1.5 (P < 0.01 vs. group 1), 37.1 +/- 6.4 (P < 0.01 vs. group 1, P = 0.0004 vs. group 6), 9.0 +/- 1.4, 26.5 +/- 3.6 (P < 0.01 vs. group 1, P < 0.03 vs. group 6), and 20 +/- 4.9 (P < 0.01 vs. group 1) for groups 1, 2, 3, 4, 5, and 6. To assess the impact of AA on ODFR production, chemiluminescence was performed on zymosan-activated Lewis whole blood from control rats and rats administered AA. AA significantly decreased peak chemiluminescence (P < 0.05) as compared with nontreated rats indicating effective ODFR scavenging. To determine whether AA and AT inhibit lymphocyte stimulation, mixed lymphocyte response testing was performed with irradiated Wistar-Furth lymphocytes as stimulator cells for Lew responder cells from rats treated as groups 3, 5, and 6. CsA significantly suppressed (P < .05) proliferation as compared with untreated controls. Neither AA nor AT enhance CsA's immunosuppressive effect by mixed lymphocyte response testing. In summary, prolongation of allograft survival with antioxidants AA and AT does not result from abrogation of lymphocyte responsiveness or alteration in CsA bioavailability. Rather, these data suggest that ODFR are involved in allograft destruction and support a role for effective antioxidant therapy in the treatment of allograft rejection.

Factors influencing weight gain after renal transplantation.

Weight gain following renal transplantation occurs frequently but has not been investigated quantitatively. A retrospective chart review of 115 adult renal transplant recipients was used to describe patterns of weight gain during the first 5 years after transplantation. Only 23 subjects (21%) were overweight before their transplant. Sixty-six subjects (57%) experienced a weight gain of greater than or equal to 10%, and 49 subjects (43%) were overweight according to Metropolitan relative weight criteria at 1 year after transplantation. There was an inverse correlation between advancing age and weight gain, with the youngest patients (18-29 years) having a 13.3% weight gain and the oldest patients (age greater than 50 years) having the lowest gain of 8.3% at 1 year (P = 0.047). Black recipients experienced a greater weight gain than whites during the first posttransplant year (14.6% vs. 9.0%; P = 0.043), and maintained or increased this difference over the 5-year period. Men and women experienced comparable weight gain during the first year (9.5% vs. 12.1%), but women continued to gain weight throughout the 5-year study (21.0% total weight gain). The men remained stable after the first year (10.8% total weight gain). Recipients who experienced at least a 10% weight gain also increased their serum cholesterol (mean 261 vs. 219) and triglyceride (mean 277 vs. 159) levels significantly, whereas those without weight gain did not. Weight gain did not correlate with cumulative steroid dose, donor source (living-related versus cadaver), rejection history, pre-existing obesity, the number of months on dialysis before transplantation, or posttransplant renal function. Posttransplant weight gain is related mainly to demographic factors, not to treatment factors associated with the transplant. The average weight gain during the first year after renal transplantation is approximately 10%. This increased weight, coupled with changes in lipid metabolism, may be significant in terms of altering risk from cardiovascular morbidity.

A prospective randomized comparison of quadruple versus triple therapy for first cadaver transplants with immediate function.

In January 1988, we initiated a prospective, randomized comparison of prophylactic antilymphoblast globulin (ALG; quadruple therapy) versus no prophylactic ALG (triple therapy) in the setting of immediate graft function (defined by a brisk diuresis and a 20% decline in serum creatinine within 24 hr). Recipients were stratified according to presence of diabetes and age greater or less than 50 years. Recipients on quadruple therapy (n = 61) received 7 days of prophylactic Minnesota ALG (5 mg/kg on day 1, 10 mg/kg on day 2, 20 mg/kg on days 3-7). CsA, 10 mg/kg/day, began on day 6. AZA began at 2.5 mg/kg/day and was adjusted according to white blood cell count. Recipients on triple therapy (n = 60) began immediate CsA, 10 mg/kg/day orally and AZA, 5 mg/kg/day, tapering to 2.5 mg/kg/day by day 8. Both groups received identical prednisone tapers beginning at 1 mg/kg/day, decreasing to 0.5 mg/kg/day by 2 weeks and to 0.15 mg/kg/day by 6 months. Demographic characteristics between groups were not different with respect to diabetes, age, sex, race, per cent panel-reactive antibodies (PRA), or HLA matching. Follow-up ranged from 2 to 4.5 years. Patient survival was 93% for the quadruple therapy group and 90% for triple therapy. Actuarial graft survival was 79% in the quadruple group and 72% in the triple group (P = 0.18). Graft loss due to rejection occurred in 6/61 receiving ALG versus 7/60 in the immediate CsA group. Three of 4 high PRA recipients in the immediate CsA group lost their grafts within 30 days compared with none in the ALG group. The mean time to graft loss was significantly longer for the quadruple therapy group (17 +/- 8 months) compared with the triple therapy group (4 +/- 5 months), P = 0.006. The total number of rejection episodes was similar for both groups (29/61 vs. 31/60), as was the number who were rejection free (51% vs. 47%). The use of OKT3 was also similar between groups (28% vs. 30%). The quadruple therapy group had a higher incidence of CMV infection: 20% vs. 7% (P < 0.05), but no grafts or patients were lost as a result. Serum Cr was not different at 1 and 12 months (1.5 and 1.6 vs. 1.6 and 1.7, respectively), nor were Cr clearances (63 and 68 vs. 60 and 63). Conclusion. Early initiation of oral CsA in the setting of immediate graft function is not associated with significant nephrotoxicity.(ABSTRACT TRUNCATED AT 400 WORDS)

Severe bleeding diathesis associated with invasive aspergillosis in transplant patients.

A severe bleeding disorder developed in eight renal transplant patients with invasive aspergillosis. The hemorrhagic diathesis was characterized by wound oozing, severe upper and lower gastrointestinal tract hemorrhage, and mucosal bleeding at other sites. This unusual coagulopathy was characterized by a prolonged thrombin time, which was corrected with protamine sulfate, and an abnormal Reptilase time. The bleeding disorder antedated the diagnosis of invasive aspergillosis in all cases. The probability that the coagulopathy was due to proteolytic enzymes elaborated by Aspergillus sp. is discussed.