Search PubMed⌕ Search

Biomedical subjects

S L Gardner

Publications and source records attributed to S L Gardner.

At least 37 records · Page 2Linked to original sources

A new species of Vexillata (Nemata: Ornithostrongylidae) from the coarse-haired pocket mouse Chaetodipus hispidus in New Mexico.

Individuals of a new species of trichostrongyloid nematode of the genus Vexillata were collected from the intestines of the coarse-haired pocket mouse Chaetodipus hispidus from eastern New Mexico. This new species possesses general features of the genus Vexillata but may be recognized as distinct from all other species by unique features of the dorsal ray of the caudal bursa and the synlophe.

Animals↗

A new species of Heterorhabditis from the Hawaiian Islands.

A new species of nematode of the genus Heterorhabditis (Nemata: Heterorhabditidae) was found during a survey of the soil entomopathogenic nematode fauna of the Hawaiian Islands. Heterorhabditis hawaiiensis sp. n. can be separated from all other species of Heterorhabditis by the length of the infective juvenile and the morphological characters of the spicules, gubernaculum, and bursa. Random amplified polymorphic DNA (RAPD) fragment analysis showed that this species also has a distinct genetic pattern in RAPD bands relative to the other 6 species or isolates of Heterorhabditis that were compared.

Animals↗

A new species of Linstowia (Cestoda: Anoplocephalidae) from marsupials in Bolivia.

A new species of cestode of the genus Linstowia (Cestoda: Anoplocephalidae) is described from marsupials of the genera Thylamys and Monodelphis. The new species (Linstowia schmidti) differs from Linstowia iheringi Zschokke, 1904, in having a much smaller strobila and reduced number of proglottids, and in the distribution of the eggs in gravid proglottids. In Bolivia, cestodes of the genus Linstowia appear to have a restricted geographic distribution, occurring in marsupials only in southeastern Bolivia near the western margin of the Chaco. This host-parasite association may represent an ecological-historical relict.

Animals↗

Parasites as probes for biodiversity.

Cestodes of the genus Linstowia, parasitic in marsupials, show patterns of coevolution and ancient historical-ecological connections. Correlated with the breakup of the austral landmasses (Gondwanaland) of the Neotropical and Australian regions from the Antarctic continent, the age of this host-parasite community is estimated to be between 60 and 70 million years old. Based on the data from the survey of parasites of mammals from throughout Bolivia and from the phylogenetic analysis of the cestodes, we urge the planners of biodiversity preserves in the neotropics to consider the Yungas of Bolivia as a region that supports an ancient ecological community worthy of consideration as a biopreserve.

Animals↗

Fixing coccidian oocysts is not an adequate solution to the problem of preserving protozoan type material.

Fresh (36 days old) sporulated oocysts of Eimeria nieschulzi were divided into 7 groups. Control oocysts were maintained at 23 C in 2% aqueous (w/v) K2Cr2O7. The 6 experimental groups were mixed with either Bouin's solution, 10% aqueous (v/v) buffered formalin, Karnovsky's solution, glutaraldehyde, paraformaldehyde, or 70% aqueous (v/v) ethanol (EtOH). After 115 days, oocysts from all 7 groups were examined under oil immersion to determine the effect of fixation on their structural integrity. The parameters examined were lengths and widths of oocysts and sporocysts, percent sporulation (%S), and percent crenation (%C) of oocysts and sporocysts. The highest destruction (%S and %C) occurred in oocysts exposed to glutaraldehyde and Karnovsky's fixatives where 100% of both oocysts and sporocysts crenated and only 8% and 48%, respectively, remained sporulated. Of the oocysts in paraformaldehyde, 93% remained sporulated, but 95%of these oocysts and 100% of the sporocyst crenated. In Bouin's solution, 75% of the oocysts were intact structurally, but of these, only 60% were still sporulated with 70% of their sporocysts crenated. Oocysts preserved in 70% EtOH were 80% intact and 70% remained sporulated, but nearly 60% of their sporocysts collapsed even though the oocyst walls were intact. Oocysts preserved in 10% buffered formalin maintained structural integrity but had lower numbers of sporulated oocysts (84%) and greater numbers of crenated oocysts (18%) than control oocysts maintained in the dichromate solution (95% and 0%, respectively).

Acetates↗

Polymorphism of eimerian oocysts can be a problem in naturally infected hosts: an example from subterranean rodents in Bolivia.

Since 1986, 364 tuco-tucos (Ctenomys spp.) representing 7 species were collected from 16 major collecting areas representing at least 4 distinct ecological habitats in Bolivia, South America. All were examined for coccidia, and 125 (34%) had oocysts in their feces including 84 of 236 (36%) Ctenomys boliviensis from tropical palm/savanna habitats; 1 of 3 (33%) Ctenomys conoveri from a chaco thorn forest; 3 of 7 (33%) Ctenomys frater from medium altitude grass habitats; and 6 of 8 (75%) Ctenomys lewisi and 31 of 35 (88%) Ctenomys opimus from high altitude/puna habitats. None of 3 Ctenomys leucodon (high altitude/puna) or 72 Ctenomys steinbachi (tropical palm/savanna) were passing oocysts when examined. The 5 infected host species all had oocysts of Eimeria opimi Lambert, Gardner, and Duszynski, 1988, in their feces. These oocysts and their sporocysts varied greatly in size, both within and between host species, but qualitative characters (e.g., residua and wall texture) remained constant. Our conclusion, that all oocysts seen were E. opimi, was supported by multigroup discriminant analysis of 256 individual oocysts, 30-67 selected randomly from each Ctenomys sp. Minimum polygons enclosing the centroid (= multivariate mean) and the spread of individuals for each species group (OTU) showed significant overlap in discriminant space, and Geisser classification showed a 55% miss rate of individuals being classified into the wrong OTUs. Thus, oocyst and sporocyst lengths and widths cannot be used to separate morphotypes of E. opimi from different Ctenomys spp. from different geographic regions of Bolivia.

Animals↗

Effect of a hydraulic jet prophylaxis system on composites.

Because air-powered devices that remove surface stain from teeth are commercially available, recent literature concerning the effect of the hydraulic jet prophylaxis system on oral tissues and restorative materials was reviewed. A study designed to compare the volume loss by different types of composites abraded by this system revealed a relatively high rate of abrasion for the small-particle composite compared with composites containing larger filler particles.

Acrylic Resins↗

Modulation by sodium butyrate of the differentiated status of a clonal pancreatic B-cell line (RIN).

RINmRH cells are a cloned cell line derived from a transplantable rat insulinoma. These cells display only some of the differentiated structure/function features of native pancreatic B-cells. In particular, they do not efficiently or reproducibly express islet B-cell surface antigens, which would otherwise render them useful for screening for the presence of anti-islet cell surface antibodies in the serum of suspected diabetic patients or their relatives. This study examines whether sodium butyrate can enhance expression of B-cell differentiation antigens on RIN cells. RIN cells were exposed to 1,2 or 4 mM butyrate for nine days, and cell growth followed. At 1 mM, butyrate inhibited cell growth by 90%. At the higher concentrations, there was a net loss in the number of cells per culture dish. Exposing the cells to 1 mM or 2 mM butyrate for two days, resulted in a 50% increase in cellular insulin content at the expense of a partial (1 mM) or complete (2 mM) loss of stimulated insulin release in response to glyceraldehyde or serine. A concentration of 1 mM butyrate was therefore used for subsequent studies. The binding to RIN cells of a panel of monoclonal antibodies (mAb's) known to bind native islet cells (R2D6, A2B5, A1D2, 3G5) as well as of serum from a diabetic patient known to carry anti-islet cell antibodies, was screened by cytofluorography or by a radio-binding assay. The relative binding affinity of the mAb's was 3G5 greater than A1D2 greater than A2B5 greater than R2D6. Only 2-3% of the cells were bound by the diabetic patient serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Coccidia (Apicomplexa: Eimeriidae) from the subterranean rodent Ctenomys opimus Wagner (Ctenomyidae) from Bolivia, South America.

Of 35 tuco-tucos (Ctenomys opimus) collected in Bolivia, South America, 31 (88%) had eimerian oocysts in their feces at the time they were examined. Eighteen (58%) of the 31 infected animals were concurrently infected with 2 or 3 eimerian species. Four species of Eimeria were recovered and are described as new species based on the characteristics of sporulated oocysts. Oocysts of Eimeria granifera n. sp. were ellipsoidal, 21.1 x 17.2 (15-26 x 11-20) micron with sporocysts ovoidal, 11.3 x 7.1 (8-14 x 5-9) micron. Oocysts of Eimeria montuosi n. sp. were spheroidal, 24.2 x 22.0 (21-28 x 18-25) micron with sporocysts ovoidal, 10.5 x 7.3 (8-14 x 6-9) micron. Oocysts of Eimeria opimi n. sp. were spheroidal to subspheroidal, 24.3 x 21.8 (18-29 x 15-26) micron with sporocysts ovoidal, 11.6 x 7.6 (10-13 x 6-9) micron. Oocysts of Eimeria oruroensis n. sp. were spheroidal to subspheroidal, 27.3 x 23.6 (23-32 x 20-28) micron with sporocysts ovoidal, 13.2 x 8.6 (10-16 x 8-11) micron.

Animals↗

Echinococcus vogeli Rausch and Bernstein, 1972, from the paca, Cuniculus paca L. (Rodentia: Dasyproctidae), in the Departamento de Santa Cruz, Bolivia.

Among approximately 2,000 mammals examined for helminths in various regions of Bolivia during 1983-1987, cysts of Echinococcus vogeli Rausch and Bernstein, 1972, were found in a single paca, Cuniculus paca L., collected at La Laguna, Departamento de Santa Cruz (lat. 16 degrees 36'W; long. 62 degrees 42'S). This record, the first from Bolivia, represents a considerable extension of the known geographic range of this species in South America. Upon analysis of the morphologic characteristics of the protoscoleces derived from the cysts, the sizes of rostellar hooks from the material from the paca were found to be well within the ranges reported in previous studies. Statistical analysis of frequency distributions of hook characteristics revealed some deviations from normality. These results indicate that parametric statistics should be applied with caution in analyses of inter-and intraspecific variation of morphologic characteristics of hooks of metacestodes of the genus Echinococcus.

Animals↗

Physiologic sequelae of prematurity: the nurse practitioner's role. Part I. Respiratory issues.

Care of the premature infant after an intensive care experience offers the pediatric nurse practitioner a myriad of challenges, depending on the infant's neonatal course. The focus of this series of articles is an overview of the common pathophysiologic, psychologic, and developmental problems that face the premature infant. This article provides a discussion of the pathophysiology, data collection, treatment modalities, complications, and education necessary to assist parents in coping and dealing with respiratory complications of prematurity.

Humans↗