Plasma Cell Myeloma in the Horse

Plasma cell myelomas in horses have been reported infrequently. Data from 10 cases, 9 from the literature and 1 new case, are used to characterize the disease in the horse. Hot-blooded horses (7/10), specifically Quarter Horses (4/10), were most often affected. Median age at diagnosis was 11 years (range, 3 mo-22 yr) and both male (5) and female horses (5) were represented equally. Clinical findings included weight loss (6/8), anorexia (4/8), fever (4/8), limb edema (4/8), pneumonia (3/8), rear leg paresis/ataxia (3/8), epistaxis (3/8), palpable lymphadenopathy (2/8), and bone pain (2/8). Anemia (8/8) was present routinely, and in three horses, RBCs were macrocytic. Leukopenia (2/8), thrombocy-topenia (2/8), and circulating plasma cells (3/8) were variable findings. Except for abnormal protein concentrations and hyponatremia (3), abnormal results from serum biochemical analysis including hypo-cholesterolemia (1), hypercalcemia (1), and azotemia (1) were reported infrequently. Hyperproteinemia (8/9), hypoalbuminemia (7/9), and hyperglobulinemia (8/9) were characteristic but not invariable findings. Monoclonal proteins (7/7) were detected in the α₂, β, or γ region by serum electrophoresis. The paraprotein's heavy chain, determined in four horses, was a subclass of IgG. Three horses had decreased concentrations of normal immunoglobulins. Variable proteinuria (trace to 4+) was detected by routine urinalysis in four of six horses. Bence Jones proteinuria was detected in one of five horses (heat precipitation) and monoclonal proteins were detected in two of three electrophoresed urine samples. Three of the horses had lytic bone lesions detected radiographically. Bone marrow aspirates were diagnostic in two of five horses. Atypical plasma cells or increased numbers of plasma cells or both were present in histologic sections of bone marrow in six of eight horses. Common extraosseous sites of plasma cell infiltration included lymph nodes (8/8), kidney (5/8), spleen (5/8), liver (3/8), lung (3/8), brain (2/8), and orbit (2/8). Two horses had intracellular and extracellular crystalline deposits.     

The Effect of Size and Diet on Gonad Production by the Chilean Sea Urchin Loxechinus albus

Conadal production was studied in Loxechinus albus (Molina, 1782) maintained in cages suspended from a long-line in the Estero Castro, Chiloé for 3 mo during the austral summer. The sea urchins were fed either an artificial diet or a natural diet consisting of the macroalgae Macrocystis pyrifera and Ulva sp. Both diets were tested for four size ranges: 40–45, 50–55, 60–65 and 70–75 mm diameter. For all four size ranges, highest gonad production was with the artificial diet. Gonad production was greatest in the 40–45 mm individuals with an increase of about 1,400% and 750% in the wet weight of gonads in individuals fed the artificial and natural diet, respectively. With the three other size ranges, the increase was nearly 100% with the artificial diet and nearly 0% with the natural diet The gonad index showed similar patterns, being highest in the smallest individuals. Small individuals fed the artificial diet would provide the most cost effective aquaculture as production is best. It is not necessary to grow L. albus to the minimal legal size for fisheries (70-mm diameter) for cost effective gonad production.     

Cloning and characterization of a bovine genomic fragment homologous to epidermal growth factor genes

Epidermal growth factor (EGF) is a potent mitogen for a variety of cell types. The 53-amino acid mature EGF protein is encoded by sequences in exons 20 and 21 of a gene spanning over 110 kb. In this study, we report the cloning and characterization of 7.5 kb of bovine genomic sequence homologous to exon 19 through 21 from EGF genes from other mammalian species. The cloned gene fragment had an unusual sequence composition in the form of an in-frame TGA codon in the coding sequence. The sequence was expressed at low levels in kidney tissue and the corresponding cDNA contained the TGA codon. The level of similarity between the bovine exonic sequence and the human, porcine, murine, feline, and canine corresponding sequences varied from 64% to 73%; however, when only sequences encoding the mature EGF protein were compared, the level of similarity between the bovine sequence and the sequence from these species was 59% to 66%. The sequence similarity of the deduced mature protein was lower (34% to 39%) than the sequence similarity of the deduced propeptide. Although the cloned sequences could originate from a bovine EGF pseudogene, the possibility exists that they originate from the functional EGF gene. An as yet unidentified mechanism to by-pass the stop codon would allow the synthesis of a functional EGF protein. Alternatively, the cloned sequence could originate from an EGF-like gene.     

革新水产营养和饲养策略优化有机水产养殖业效益

通过饲喂使用一种独特的可持续生产的,有机认证的蛋白原料的无鱼粉日粮,海虾在一个生长季节可以增重高达23克。这一生产系统包括低饲养密度,自然手段调控微生物食物链,改善环境和动物福利。生产成本显著降低,生产的有机产品的价值提高。     

一种生物病虫害控制模型的进化算法处理

为控制蘑菇种植过程中尖眼蕈蚊数量,利用线虫和尖眼蕈蚊数量变化的动态关系模型,应用分布估计算法对控制干涉次数和控制数量进行优化处理,将其与遗传算法结果进行比较.结果表明:该算法在控制次数略有增加情况下,可以取得较小目标函数值,并且算法稳定收敛,该结果可以作为一种理想的控制优化方案.分布估计算法可以用来处理此类动态关系模型的优化问题.     

Sectional notes

American Journal of Potato Research -     

Information needs and priorities for assessing the sensitivity of marine birds to oil spills

Our experience in developing models to predict the potential impacts of oil spills on colonially breeding marine birds has revealed some major gaps in the information available on these systems. We consider the availability of data for a variety of parameters of seabird biology that are required in modelling efforts, and assign provisional priorities to our information needs. In order to develop means of predicting the impacts of oil spills on seabirds, we suggest that colony- or site-specific information on the timing of reproduction and colony occupancy, chick growth rates and body weights, several metabolic parameters, flight speed, and food load size is of relatively low overall priority. Intermediate priority is assigned to the collection of specific data on the dynamics of oil spills, the age and breeding structure of the populations, reproductive success, foraging activity budgets and flight paths, flight costs, and the response of growing chicks to food deprivation. We suggest that studies of seabird biology should give highest priority to obtaining information on population sizes, the probability of adult death upon encountering a spill, age-specific fecundity and survivorship, the time required in foraging trips, the lag time in the response of birds to an oil spill, foraging rate as a function of resource density, and changes in the availability of resources to the birds as a consequence of oil spills.