Transactions of the American Microscopical Society最新文献_第5页

Further ultrastructural observations on the epidermis of phoronids: Phoronis australis and Phoronis hippocrepia 滇滇滇滇滇和滇滇滇滇滇表皮超微结构的进一步观察

Transactions of the American Microscopical Society Pub Date : 1993-10-01 DOI: 10.2307/3226563

A. Aguirre, I. Fernández, F. Pardos, C. Roldán, J. Benito

{"title":"Further ultrastructural observations on the epidermis of phoronids: Phoronis australis and Phoronis hippocrepia","authors":"A. Aguirre, I. Fernández, F. Pardos, C. Roldán, J. Benito","doi":"10.2307/3226563","DOIUrl":"https://doi.org/10.2307/3226563","url":null,"abstract":"The epidermis of two species of phoronids, Phoronis australis and Phoronis hippocrepia, was studied using transmission electron microscopy and histochemical techniques. Results were compared with information available for Phoronis psammophila. The epidermis of each of the three species is similar with respect to certain cell types, namely supporting cells, fine-granule-containing cells, and four types of gland cells. These species differ, however, in abundance and distribution of each cell type. Differences may be related to different degrees of lubrication produced in various kinds of habitats (epifaunal, rocky, and sandy habitats). On the other hand, these differences may be related to burrowing activities in the three kinds of substrates. We conclude that possible correlations among structural patterns of the epidermis and various habitats primarily involve the relative abundance and distribution of gland-cell types along the trunk and ampulla. Phoronids are marine tube-dwelling invertebrates. The two species used for the present work, Phoronis australis Haswell, 1883, and Phoronis hippocrepia Wright, 1856, and a third species, Phoronis psammophila Cori, 1889, to which they are compared, build tubes in different substrates. P. psammophila lives in the intertidal and shallow subtidal zones (0-18 m depth) in sandy or muddy sediments, and its tube is covered by aggregated sediment particles (Emig, 1971; Fernandez et al., 1991); P. hippocrepia is found from the intertidal zone to 55 m depth, burrowing in rocks or empty shells or incrusting hard substrates; its tube is sinuous, without aggregated particles, except on the portion of the tube outside of the substrate (Emig, 1971; Emig & Bailey-Brock, 1987). P. australis occurs between the low-tide mark to 36 m depth and builds its tube in the tube wall of cerianthids, which may be considered a hard substrate (Emig, 1971; Emig et al., 1972). A detailed description of the epidermal cell types and their distributions along the trunk of P. psammophila was provided by Fernandez et al. (1991), who confirmed the statements of Pourreau (1979) relative to the role played by epidermal gland cells in tube construction. We have studied the ultrastructure of the epidermis of the trunk and ampulla of P. australis and P. hippocrepia in order to compare these species with P. psammophila and to describe possible relationships between the structure of the epidermis and habitat. I We thank Dr. C. C. Emig (Station Marine d'Endoume, Marseille) for the facilities needed to collect specimens of Phoronis hippocrepia and Drs. G. San Martin and E. Garcia Raso for kindly providing the specimens of Phoronis australis used in this study. This work was supported by a research grant (PB 860010) of the Comisi6n Interministerial de Ciencia y Tecnologia (CICYT). TRANS. AM. MICROSC. SOC., 112(4): 280-291. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 207.46.13.57 on Thu, 08 Sep 2016 ","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"14 1","pages":"280-291"},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81102284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

The biology of flatworms (Platyhelminthes): parenchyma cells and extracellular matrices 扁形虫的生物学:薄壁细胞和细胞外基质

Transactions of the American Microscopical Society Pub Date : 1993-10-01 DOI: 10.2307/3226561

David Bruce Conn

引用次数: 56

Effects of thrombopoietin on platelet counts, %35S incorporation into platelets, and splenic megakaryocyte size and number in sublethally irradiated mice 血小板生成素对亚致死照射小鼠血小板计数、%35S入血小板及脾巨核细胞大小和数量的影响

Transactions of the American Microscopical Society Pub Date : 1993-10-01 DOI: 10.2307/3226565

R. Culberson, T. Schultz, T. McDonald

引用次数: 0

An agglutination procedure for determining the presence of antibodies to species of Naegleria 测定耐格氏菌种类抗体存在的一种凝集程序

Transactions of the American Microscopical Society Pub Date : 1993-10-01 DOI: 10.2307/3226567

T. M. Kollars, W. Wilhelm

引用次数: 1

Resolution of the Taxonomic Status of the Freshwater Sponges Eunapius mackayi, E. igloviformis, and Spongilla johanseni (Porifera: Spongillidae) 淡水海绵马卡伊海鞘、浅形海鞘和johanseni (porfiera:海绵科)分类地位的确定

Transactions of the American Microscopical Society Pub Date : 1993-10-01 DOI: 10.2307/3226562

H. Reiswig, A. Ricciardi

引用次数: 6

Effects of Sediments on Estimates of Bacterial Density 沉积物对细菌密度估计的影响

Transactions of the American Microscopical Society Pub Date : 1993-10-01 DOI: 10.2307/3226566

R. L. Kepner, J. Pratt

{"title":"Effects of Sediments on Estimates of Bacterial Density","authors":"R. L. Kepner, J. Pratt","doi":"10.2307/3226566","DOIUrl":"https://doi.org/10.2307/3226566","url":null,"abstract":"We compared direct epifluorescent microscopic bacterial counts using either acridine orange [AO; 3,6-bis(dimethylamino)acridinium chloride] or DAPI (4',6-diamidino2-phenylindole) in the presence and absence of fine sediments. Differences in a time-series of population estimates obtained using either AO or DAPI direct-count methods were greater in sediment-amended cultures. In the presence of sediments, DAPI yielded significantly lower estimates of bacterial densities than AO. A sediment-addition experiment indicated that DAPI counts may be more sensitive to sediment presence than AO counts, although interaction between treatments (stain, sediment) clouds statistical interpretation. Variation between replicate cultures was greater than between subsamples of preserved combined samples. Mean differences attributable to choice of stain may be as great as differences attributable to potential masking effects of sediments. Despite culture variability, DAPI and AO methods yielded count estimates agreeing within an order of magnitude. Greater correspondence between counts was observed for turbid natural water samples spanning a more limited range of bacterial concentrations. Identifying and interpreting the biotic and abiotic factors responsible for the regulation of bacterial numbers is a major goal of microbial ecology. Bacteria have been enumerated in several ways, with many of the same techniques being applied in a variety of systems. If reported usage is indicative, methods of direct microscopic visualization are increasingly favored over standard platecount techniques which, by necessity, exert a selective effect leading to underestimates of total bacterial numbers. A serious and recognized drawback of plate counts is that no single medium will culture all bacteria (Buck, 1979), yet the presence of large numbers of bacteria (regardless of culturability) may be of great significance. Recently, epifluorescent direct-count techniques have become the methods of choice for enumeration of total bacteria (Fry, 1988). However, clear differences in numbers of bacteria observed depend upon both staining technique and physico-chemical characteristics of the sample. Two fluorochrome stains are most often used in direct-count methods. DAPI (4',6-diamidino-2-phenylindole) is a DNA-specific stain that fluoresces blue or bluish-white when bound to DNA and excited with light at a wavelength of 365 nm. When unbound or bound to non-DNA material, it may fluoresce over a range of yellow colors. As with the other most commonly used strain, AO [3,6-bis(dimethylamino)acridinium chloride or acridine orange], bacteria are identified based not only upon color but also upon size and shape. AO binds to both DNA and RNA, and the excitation maximum for AO is approximately 470 nm. Both DAPI and AO stain bacteria and other fine particulate organic matter (FPOM) differentially. Two experiments were performed to assess differences in bacterial directcount methods. In particular, we ","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"6 1","pages":"316-330"},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80020658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Ultrastructural changes in the body wall of Neoechinorhynchus cylindratus (Acanthocephala) associated with reproductive activity 棘头目新棘喙虫体壁超微结构变化与生殖活动的关系

Transactions of the American Microscopical Society Pub Date : 1993-07-01 DOI: 10.2307/3226679

O. Amin, F. H. Whittaker, K. Klueber, J. Hoffpauir

引用次数: 4

Blood Chemical Changes in Cotton Rats, Sigmodon hispidus, Infected with Parastrongylus costaricensis (Nematoda: Angiostrongyloidea) 感染costaric副圆线虫(线虫:管圆线虫科)的棉大鼠血液化学变化

Transactions of the American Microscopical Society Pub Date : 1993-07-01 DOI: 10.2307/3226680

J. Ubelaker, L. Wilkerson, J. Leveson, A. Marengo-Rowe

{"title":"Blood Chemical Changes in Cotton Rats, Sigmodon hispidus, Infected with Parastrongylus costaricensis (Nematoda: Angiostrongyloidea)","authors":"J. Ubelaker, L. Wilkerson, J. Leveson, A. Marengo-Rowe","doi":"10.2307/3226680","DOIUrl":"https://doi.org/10.2307/3226680","url":null,"abstract":"Abstract. Serum analytes of adult laboratory-raised cotton rats, Sigmodon hispidus, infected with Parastrongylus costaricensis were compared with those of ageand sexmatched control animals. Parasitism produced significant longand short-term changes in some analytes. Long-term changes included reductions in levels of sodium, chloride, creatinine, triglycerides, and calcium as well as elevation of lactate dehydrogenase (LDH) levels that occurred during the first 32 days of the infection. Short-term changes were correlated to specific developmental stages of the life cycle of the parasite. Thus, immediately after infection (when the third-stage larvae occur in mesenteric lymph nodes and vessels), an increase occurred in the levels of bilirubin, globulins, and proteins. As young juvenile worms matured in the mesenteric vasculature, globulin levels had a tendency to rise, and the elevation became significant at day 16. Egg laying was accompanied by decreases in levels of alkaline phosphatase (AP) and alanine aminotransferase (ALT). Hatching of eggs and passage of first-stage larvae through gut tissues had the most profound effect. At day 24, a dynamic decrease occurred in LDH, ALT, and aspartate aminotransferase (AST) while a downward drift in AP occurred. An electrolyte disturbance occurred in which potassium (K+ ) levels decreased (day 24) and then rebounded (day 28) while sodium (Na+) levels normalized and then declined. Changes were not observed in levels of creatinine phosphokinase (CPK), uric acid, carbon dioxide (CO2), glucose, protein, and cholesterol.","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"13 1","pages":"217-229"},"PeriodicalIF":0.0,"publicationDate":"1993-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83591033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Ultrastructural observations on spermatogenesis in Phascolion cryptum (Sipuncula) 隐囊Phascolion cryptum (Sipuncula)精子发生的超微结构观察

Transactions of the American Microscopical Society Pub Date : 1993-07-01 DOI: 10.2307/3226678

A. Reunov, M. E. Rice

引用次数: 16

Changes in freshwater meiofauna communities along the groundwater-hyporheic water ecotone 地下水-潜水交错带淡水小型动物群落的变化

Transactions of the American Microscopical Society Pub Date : 1993-07-01 DOI: 10.2307/3226677

D. Williams

引用次数: 12