Indocyanine green clearance and ammonia tolerance were measured in anesthetized dogs with 60% hepatectomy, 40% hepatectomy, portacaval shunt, and hepatic artery ligation. With a dose of 0.5 mg of indocyanine green/kg of body weight, plasma clearance of the dye was significantly (P less than 0.001) delayed only in dogs with 60% hepatectomy. Ammonia tolerance was abnormal in dogs in this group, because after they were given a gastric challenge load of an ammonium salt, they had a 5-fold increase in plasma ammonia concentration, compared with a 2.5-fold increase in the control group. Before challenge loading, base-line plasma ammonia concentration was significantly (P less than 0.05) increased within 5 minutes after surgical preparation of the portacaval shunt. After challenge loading the stomach with an ammonium salt, dogs with portacaval shunt had increased plasma ammonia concentration, but the amount was not significantly different from postchallenge-loading values in control dogs. Dogs with 40% hepatectomy and with hepatic artery ligation could not be differentiated from control dogs by indocyanine green clearance or by ammonia tolerance testing. Abnormal tolerance to a challenge gastric load of an ammonium salt or delayed clearance of indocyanine green may indicate marked loss of functional hepatic mass, but normal tolerance or normal dye clearance may not exclude liver disease or dysfunction. Seemingly, base-line plasma ammonia concentration was a sensitive indicator of abnormal portal circulation.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
Ice cores from Penny Ice Cap, Baffin Island, Canada, provide continuous Holocene records of oxygen isotopic composition (delta18O, proxy for temperature) and atmospheric impurities. A time scale was established with the use of altered seasonal variations, some volcanic horizons, and the age for the end of the Wisconsin ice age determined from the GRIP and GISP2 ice cores. There is pre-Holocene ice near the bed. The change in delta18O since the last glacial maximum (LGM) is at least 12.5 per mil, compared with an expected value of 7 per mil, suggesting that LGM ice originated at the much higher elevations of the then existing Foxe Dome and Foxe Ridge of the Laurentide Ice Sheet. The LGM delta18O values suggest thick ice frozen to the bed of Hudson Bay. 相似文献
The effect of antimicrobial supplementation of pigs on the capacity of their sera to influence proliferation and protein turnover in cultured muscle cells was evaluated. Mitogenic activity of sera increased when pigs were fed ASP250 (P less than .005) or carbadox (P less than .001), whereas the mitogenic activity of serum from pigs receiving the basal diet remained unchanged (P = .5). Additionally, sera from ASP250-fed pigs significantly decreased (P less than .001) total cellular protein degradation compared with sera obtained from the same pigs prior to supplementation. Neither ASP250 nor carbadox stimulated proliferation of myogenic cells when added to the culture media. Inclusion of ASP250 in swine diets altered the composition of their sera in a way that stimulated muscle cell proliferation and reduced the rate of protein degradation in cultured myogenic cells. Likewise, the inclusion of carbadox in swine diets increased the ability of their sera to stimulate cultured muscle cell proliferation. 相似文献
Differences in macroscopic measurements of the gastrointestinal tract have been hypothesized to correlate with the browser–grazer continuum in the natural diet of ruminants. However, to what extent these characteristics represent species‐specific traits, or respond to the actually ingested diet, remains to be investigated. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups and fed, for 3 months, either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only. After culling, macroscopic measurements were compared between groups. The macroscopic anatomy of the addax showed many characteristics considered typical for grazing or ‘cattle‐type’ ruminants. While both diet groups had mesenteric, pericardial and perirenal adipose tissue, these depots were subjectively more pronounced in concentrate‐fed animals. Hay‐fed animals had significantly heavier filled forestomach compartments, with corresponding significantly longer linear measurements. Masseter muscles and the surface of first‐order omasal leaves were significantly more prominent in hay‐fed animals, reflecting possible adaptations to overcome resistance of grass forage and to reabsorb fluid from increased rumination, but differences were not as distinct as reported between ‘cattle‐type’ and ‘moose‐type’ ruminants. Some measurements such as reticular crests and empty foregut mass remained stable between groups, indicating possibly genetically pre‐defined characteristics less prone to change in adult life. The results emphasize the adaptability of ruminant digestive tract anatomy in adult animals even after a short period of time, but also suggest limits to this adaptability that reveals a species‐specific anatomy regardless of the diet actually consumed. 相似文献
Over a six-month period, 6% of 313 cats evaluated hematologically had either leukoerythroblastosis or normoblastemia. Diseases associated with these hematological conditions included haemobartonellosis, hepatic lipidosis, trauma, viral and bacterial infections, myeloproliferative disorders, and hemangiosarcoma. The finding of leukoerythroblastosis or normoblastemia may aid in diagnosing cats presenting with nonspecific signs. 相似文献
Previous studies in our laboratory suggested that there was positive selection of B cells during early development in the appendix of normal and V(H) mutant (ali/ali) rabbits. Preferential expansion and survival of B lymphocytes was affected by the Ig V(H) frameworks 1 and 3 sequences expressed on the cell surface. We demonstrated a specific interaction between rabbit CD5 and the V region of rabbit heavy chains and suggested that CD5 is a potential selecting ligand for B-cell surface immunoglobulin framework region sequences. To further investigate the role of CD5 in rabbit B-cell selection and survival we prepared recombinant constructs and obtained stable expression of the three scavenger receptor cysteine-rich (SRCR) extracellular domains of rabbit CD5. Here we describe the production and purification of this expressed recombinant CD5 protein, polyclonal antibody obtained by immunization of a goat and initial production and characterization of specific mAbs against peptides selected from each sequenced SRCR domain. 相似文献
Percutaneous gastrostomy tubes were placed non-endoscopically in 31 cats and 10 dogs using either a rigid insertion tube (n=13) or an Eld gastrostomy tube applicator (n=28). Tubes were placed successfully in 38 of the 41 animals and the consequent feeding was of therapeutic benefit to 31 of the animals. Six of 41 died or were euthanased for reasons unrelated to gastrostomy. In four cases (10 per cent), gastrostomy failed with respect to correct tube placement or tube feeding. Overall complications occurred in 18 of 41 animals. Severe procedural complications occurred in two cats; a cardiorespiratory arrest during pharyngeal manipulation and erroneous tube placement through the distal oesophagus. Moderate late complications included peristomal food leakage (n=2), peristomal abscess (n=2) and pyloric outflow obstruction by a migrated tube (n=1). Complications associated with the feeding procedure, nausea and vomiting (n=3), led to aspiration pneumonia in one case. 相似文献
Recovery from disturbances is a prominent measure of forest ecosystem resilience, with swift recovery indicating resilient systems. The forest ecosystems of Central Europe have recently been affected by unprecedented levels of natural disturbance, yet our understanding of their ability to recover from disturbances is still limited.
Objectives
We here integrated satellite and airborne Lidar data to (i) quantify multi-decadal post-disturbance recovery of two indicators of forest structure, and (ii) compare the recovery trajectories of forest structure among managed and un-managed forests.
Methods
We developed satellite-based models predicting Lidar-derived estimates of tree cover and stand height at 30 m grain across a 3100 km2 landscape in the Bohemian Forest Ecosystem (Central Europe). We summarized the percentage of disturbed area that recovered to >?40% tree cover and >?5 m stand height and quantified the variability in both indicators over a 30-year period. The analyses were stratified by three management regimes (managed, protected, strictly protected) and two forest types (beech-dominated, spruce-dominated).
Results
We found that on average 84% of the disturbed area met our recovery threshold 30 years post-disturbance. The rate of recovery was slower in un-managed compared to managed forests. Variability in tree cover was more persistent over time in un-managed forests, while managed forests strongly converged after a few decades post-disturbance.
Conclusion
We conclude that current management facilitates the recovery of forest structure in Central European forest ecosystems. However, our results underline that forests recovered well from disturbances also in the absence of human intervention. Our analysis highlights the high resilience of Central European forest ecosystems to recent disturbances.
Poinsettia cultivars Supjibi and Freedom were grown in eight hydroponic solutions to develop a baseline solution for further nutritional studies. Four solutions contained nitrogen (N) from Ca(NO3)2‐4H2O and KNO3 (denoted as ‐NH4) and four contained Ca(NO3)2‐4H2O, KNO3, nitric acid, and NH4NO3 as the N sources (denoted as +NH4). The four ‐NH4 and +NH4 solutions were further divided by an IX or 2X rate of micronutrients [boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn)] (denoted as IX or 2X). A factorial of these four solutions at 2 concentrations (100 mg L1 of N and potassium (K) and 15 mg L1 phosphorus (P), or 300 mg L1 of N and K and 46 mg L‐1 P) was studied. Greater leaf and stem dry weight for both ‘Supjibi’ and ‘Freedom’ was observed in plants grown with the +NH4 solutions, with a larger increase occurring with’ Supjibi’. Leaf NH4‐N content for both cultivars was higher for both the 100 and 300 mg L‐1 N and K fertilization rates when NH4‐N was included. The leaf K content was highest for the plants grown with the +NH/2X solution for ‘Supjibi’, for both fertilization rates, and leaf K content increased as the K application rate increased. Results indicate that for nutritional studies with poinsettias, hydroponic solutions should include between 12.5% to 33% of the N in the NH4 form, a calcium magnesium (Ca:Mg) ratio of 2:1, and a micronutrient concentration of (mg I/1) 0.5, 0.02, 6.6, 0.5, 0.1, and 0.05, respectively, for B, Cu, Fe, Mn, Mo, and Zn, for adequate plant growth. 相似文献
Summary The conuco in Cuba is a large garden or a small field where agriculture is practiced in a traditional way. The history of the conuco is discussed. Composition and structure of actual conucos are described on the basis of four cases studied in Eastern Cuba. Their cultivated plants came from nearly all regions of diversity of the world. The crops from the Central American and Mexican region are most important. The great diversity of different crops as well as the marked variation within most of the cultivated plants stress the importance of the conuco as a reservoir for plant genetic resources.
Der Conuco — ein bedeutendes Reservoir für pflanzliche genetische Ressourcen in Kuba
Zusammenfassung Der kubanische Conuco ist ein größerer Garten oder ein kleineres Feld mit traditioneller landwirtschaftlicher Produktion. Die Geschichte des Conuco wird diskutiert. Zusammensetzung und Struktur aktueller Conucos werden auf der Grundlage von vier ostkubanischen ausgewählten Fallbeispielen beschrieben. Ihre Kulturpflanzen stammen beinahe aus allen Mannigfaltigkeitszentren der Welt. Besonders bedeutsam sind die Kulturpflanzen der mittelamerikanischen und mexikanischen Region. Die große Mannigfaltigkeit unterschiedlicher Fruchtarten und die ausgeprägte infraspezifische Variabilität bei den meisten Kulturpflanzen unterstreichen die Bedeutung des Conuco als Reservoir für pflanzliche genetische Ressourcen.