An improved method for studying the condition of fish, with an example using Pacific sardine Sardinops sagax (Jenyns)

The statistical treatment of condition used in many previous studies has been to determine a predicted weight for a fish, and to calculate a ratio of actual to predicted weight. The ratios obtained, known as condition factor K , are then further analysed using analysis of variance or other techniques to relate changes in K to other independent variables. It is suggested that condition can be studied better by using a single model to analyse the response of fish weight to a number of factors simultaneously. This approach affords benefit from the simplicity of using an integrated analysis and avoids problems with skewed distributions of ratios. An example using data on the Pacific sardine, Sardinops sagax (Jenyns), is given. Changes in condition of this fish due to monthly, yearly and temperature effects are calculated.     

SUMMER FEEDING HABITS OF DALL'S PORPOISE, PHOCOENOIDES DALLI, IN THE SOUTHERN SEA OF OKHOTSK

Stomach contents were analyzed from 85 Dall's porpoises, Phocoenoides dalli , taken in the southern Sea of Okhotsk during the summer of 1988. Thirteen species of fish and five species of cephalopods were identified. Fishes comprising 9 families were predominant and made up 79.9% of the total number of prey, with an overall occurrence in the stomachs of 100%. Three families of cephalopods made up 20.1% of the total number of prey ingested, with an overall occurrence of 74%. The Japanese pilchard, Sardinops sagax melanostictus , was the primary prey and represented 72.0% of the total prey in 97.3% of the stomachs examined. The gonatid squid, Berryteuthis magister , ranked second and made up 16.9% of the total prey in 61.6% of the stomachs. Walleye pollock, Theragra chalcogramma , was the third most abundant prey item consumed and represented 6.0% of the total, with an occurrence of 53.4%. Composition of the sample by the calculated total mass and caloric intake supports the numeric findings on the relative importance of the three major prey species to the DaIl's porpoise diet. The Japanese pilchard was clearly dominant using these indices and constituted 65.4% of the total mass and 80.7% of the caloric intake. Berryteuthis magister made up 26.8% of the mass and 15.5% of the caloric intake. Walleye pollock contributed the least to the diet with 7.9% of the total mass and 3.8% of the caloric intake. Volumetric data indicate that porpoises are feeding heavily on Japanese pilchard throughout the daylight hours. Berryteuthis magister was probably fed upon in the late night or early morning hours. Occurrence of both Dall's porpoise and Japanese pilchard in the coastal waters of the southern Sea of Okhotsk is seasonal. The summer movements of Dall's porpoise into this region may be related to the seasonal migration and abundance of the Japanese pilchard.     

Thermal behavior of the Pacific sardine (Sardinops sagax) acclimated to different thermal cycles

The study of thermal behavior of fishes provides useful data to enable predictions of the effect of climatic change on populations so as to ensure good management of fisheries. The Pacific sardine has a complex population dynamics; three subpopulation have been proposed (cold, temperate and warm).We exposed Sardinops sagax caeruleus (temperate sub-population) to two different thermal cycles, which were chosen to be consistent with the temperatures reported in two distant places Cedros Island (CIc: 18–23 °C) and San Pedro (SPc: 13–18 °C).The thermal behavior of the SPc and CIc sardines was affected by acclimation treatment: the interval of thermal preference was 17.1–19.9 and 16.0–18.8 °C, while the lethal temperatures interval (LT50) was 7.7–25.6 and 6.9–24.3 °C, and the critical limits CTMax and CTMin were 7.1–32.2 and 5.5–30.4 °C, respectively.The results of thermal behavior showed that sardines of the temperate subpopulation are more tolerant to cold; this might suggest that they would be more able to survive in California and Oregon than in Baja California Sur and the Gulf of California.     

Can plants use entomopathogens as bodyguards?

For 20 years, ecologists have been gathering evidence in support of the hypothesis that plants can use insect natural enemies such as predators and parasitoids as bodyguards to protect themselves from herbivory, but entomopathogens have escaped this consideration. We extend the bodyguard hypothesis to ask whether plants can use entomopathogens as bodyguards. We first discuss the evolutionary context of such tritrophic interactions and then categorize possible mechanisms as: (1) maintaining a population of bodyguards on the plant surface, (2) increasing contact rates between insect host and pathogen and (3) increasing the susceptibility of the host. We explore these mechanisms further, examining published studies for evidence for the hypothesis. We then discuss potential costs to the plant of promoting pathogens as bodyguards which may include a reduction in the efficiency of other "bodyguard" species, the incidental promotion of plant pathogens and the risk of entomopathogens developing phytopathogenicity. Aside from our intention to stimulate the testing of the bodyguard hypothesis with entompathogens and to provide a conceptual framework for this, we hope to bring evolutionary ecology and insect pathology closer together.     

Neuropathology of mitochondrial diseases

The term “mitochondrial diseases” (MD) refers to a group of disorders related to respiratory chain dysfunction. Clinical features are usually extremely heterogeneous because MD may involve several tissues with different degrees of severity. Muscle and brain are mostly affected, probably because of their high dependence on oxidative metabolism. Muscle can be the only affected tissue or involved as a part of a multi-system disease; ragged red fibers, accumulation of structurally altered mitochondria and cytochrome-c-oxidase (COX) negative fibers are the main pathological features. In mitochondrial encephalopathies, central nervous system (CNS) structures are affected according to different patterns of distribution and severity. Characteristic lesions are neuronal loss, vasculo-necrotic changes, gliosis, demyelination and spongy degeneration. In accordance with either grey matter or white matter involvement two main groups of diseases may be distinguished. Neuronal loss and vasculo-necrotic multifocal lesions are the common features of grey matter involvement; demyelination and spongy degeneration occur when white matter is affected, often associated with less severe lesions of the grey structures. Grey matter lesions are prevalent in MERRF, MELAS, Alpers and Leigh syndromes. White matter involvement is always seen in Kearns-Sayre syndrome and was recently described in mtDNA depletion syndrome linked to dGK mutations and in the rare conditions associated with complex I and II deficiency. In this review we describe the main histopathological features of muscle and CNS lesions in mitochondrial diseases.     

Biocontrol bacteria selected by a direct plant protection strategy against avocado white root rot show antagonism as a prevalent trait

Aim: This study was undertaken to study bacterial strains obtained directly for their efficient direct control of the avocado white root rot, thus avoiding prescreening by any other possible mechanism of biocontrol which could bias the selection. Methods and Results: A collection of 330 bacterial isolates was obtained from the roots and soil of healthy avocado trees. One hundred and forty‐three representative bacterial isolates were tested in an avocado/Rosellinia test system, resulting in 22 presumptive protective strains, all of them identified mainly as Pseudomonas and Bacillus species. These 22 candidate strains were screened in a more accurate biocontrol trial, confirming protection of some strains (4 out of the 22). Analyses of the potential bacterial traits involved in the biocontrol activity suggest that different traits could act jointly in the final biocontrol response, but any of these traits were neither sufficient nor generalized for all the active bacteria. All the protective strains selected were antagonistic against some fungal root pathogens. Conclusions: Diverse bacteria with biocontrol activity could be obtained by a direct plant protection strategy of selection. All the biocontrol strains finally selected in this work were antagonistic, showing that antagonism is a prevalent trait in the biocontrol bacteria selected by a direct plant protection strategy. Significance and Impact of the Study: This is the first report on the isolation of biocontrol bacterial strains using direct plant protection strategy in the system avocado/Rosellinia. Characterization of selected biocontrol bacterial strains obtained by a direct plant protection strategy showed that antagonism is a prevalent trait in the selected strains in this experimental system. This suggests that antagonism could be used as useful strategy to select biocontrol strains.     

Natural pathology of the Baboon (Papio spp.)

Background Baboons are useful animal models for biomedical research, but the natural pathology of the baboon is not as well defined as other non‐human primates. Methods A computer search for all morphologic diagnoses from baboon necropsies at the Southwest National Primate Research Center was performed and included all the natural deaths and animals euthanized for natural causes. Results A total of 10,883 macroscopic or microscopic morphologic diagnoses in 4297 baboons were documented and are presented by total incidence, relative incidence by sex and age‐group, and mean age of occurrence. The most common diagnoses in descending order of occurrence were hemorrhage, stillborn, amyloidosis, colitis, spondylosis, and pneumonia. The systems with the most diagnoses were the digestive, urogenital, musculoskeletal, and respiratory. Conclusion This extensive evaluation of the natural pathology of the baboon should be an invaluable biomedical research resource.     

养殖乌鳢类立克次体感染的超微病理学研究

应用电子显微镜技术,观察了养殖乌鳢RLO感染主要内脏器官超微结构病理变化,并初步探讨了发病机制。观察发现：RLO寄生细胞明显肿大,胞质电子密度低,细胞器肿大、溶解,RLO可随肿胀、破裂的细胞进人组织间隙;在一些寄生细胞内尚发现变性的RLO。内脏组织细胞普遍肿大,细胞器分散、稀少,线粒体除明显肿胀、嵴断裂消失外,尚发现坏死性变化即出现致密核心或无定形的电子密度物质;粗面内质网扩张、破裂和脱颗粒;部分细胞内溶酶体增多,胞质内发现明显的髓鞘样结构;核肿大或核固缩、溶解,并可见核内出现髓鞘样结构和核包含物。     

Validation of Normal Human Bronchial Epithelial Cells as a Model for Influenza A Infections in Human Distal Trachea

Primary normal human bronchial/tracheal epithelial (NHBE) cells, derived from the distal-most aspect of the trachea at the bifurcation, have been used for a number of studies in respiratory disease research. Differences between the source tissue and the differentiated primary cells may impact infection studies based on this model. Therefore, we examined how well-differentiated NHBE cells compared with their source tissue, the human distal trachea, as well as the ramifications of these differences on influenza A viral pathogenesis research using this model. We employed a histological analysis including morphological measurements, electron microscopy, multi-label immunofluorescence confocal microscopy, lectin histochemistry, and microarray expression analysis to compare differentiated NHBEs to human distal tracheal epithelium. Pseudostratified epithelial height, cell type variety and distribution varied significantly. Electron microscopy confirmed differences in cellular attachment and paracellular junctions. Influenza receptor lectin histochemistry revealed that α2,3 sialic acids were rarely present on the apical aspect of the differentiated NHBE cells, but were present in low numbers in the distal trachea. We bound fluorochrome bioconjugated virus to respiratory tissue and NHBE cells and infected NHBE cells with human influenza A viruses. Both indicated that the pattern of infection progression in these cells correlated with autopsy studies of fatal cases from the 2009 pandemic.     

LIGHT信号通路在鼠衣原体生殖道感染中的作用

【目的】初步探讨与单纯疱疹病毒糖蛋白D竞争结合疱疹病毒侵入介体的淋巴毒素类似物(lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells,LIGHT)在抗衣原体感染免疫及介导衣原体生殖道病理损伤过程的作用。【方法】用1×104IFUs的Mo Pn经生殖道感染野生型(wild type,wt)、LIGHT KO小鼠,每组一半小鼠于感染后49d,再次感染相同剂量的Mo Pn。每隔3-4 d取生殖道分泌物,测定其中衣原体包涵体的数量。初次感染后80d,处死小鼠,眼眶取血,分离血清,用间接免疫荧光法测定其中抗体类型及效价;同时分离生殖道,肉眼观察其输卵管、子宫角水肿程度,然后甲醛固定、切片,H&E染色后,显微镜下观察各组织炎性浸润程度和管腔水肿程度。分离小鼠脾细胞,体外用衣原体EB刺激,测定上清中IL-4、IL-5、IL-17和IFN-γ等细胞因子水平。【结果】LIGHT KO小鼠阴道带菌时间与wt组相当,大部分小鼠均在原发感染后28d左右完全清除感染,且均产生对再次感染的免疫力。LIGHT KO和wt小鼠子宫角和输卵管均出现一定程度的病变,但差异无统计学意义。两组小鼠在原发和继发感染Mo Pn后,均产生高效价的特异性抗Mo Pn Ig G抗体,总抗体及各Ig G抗体亚类效价差异均无统计学意义(P>0.05),且Ig G2a/Ig G1比值均大于1。和wt小鼠一样,LIGHT KO小鼠脾淋巴细胞经衣原体再次刺激后均可产生较高水平的IFN-γ和IL-17,且未能检测到IL-4和IL-5。【结论】小鼠抗Mo Pn生殖道感染及Mo Pn引起的生殖道病理损伤不依赖于LIGHT信号通路。     

Microvillus inclusion disease: a genetic defect affecting apical membrane protein traffic in intestinal epithelium

The striking similarities between microvillus inclusions (MIs) in enterocytes in microvillus inclusion disease (MID) and vacuolar apical compartment in tissue culture epithelial cells, led us to analyze endoscopic biopsies of duodenal mucosa of a patient after the samples were used for diagnostic procedures. Samples from another patient with an unrelated disease were used as controls. The MID enterocytes showed a decrease in the thickness of the apical F-actin layer, and normal microtubules. The immunofluorescence analysis of the distribution of five apical membrane markers (sucrase isomaltase, alkaline phosphatase, NHE-3 Na⁺/H⁺ exchanger, cGMP-dependent protein kinase, and cystic fibrosis trans-membrane conductance regulator), showed low levels of these proteins in their standard localization at the apical membrane as compared with normal duodenal epithelium processed in parallel. Instead, four of these markers were found in a diffuse distribution in the apical cytoplasm, below the terminal web (as indicated by co-localization with F-actin and cytokeratin 19), and in MIs as well. The basolateral protein Na⁺-K⁺ATPase, in contrast, was normally localized. These results support the hypothesis that MID may represent the first genetic defect affecting apical membrane traffic, possibly in a late step of apical exocytosis.