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G D Cain

Publications and source records attributed to G D Cain.

At least 19 recordsLinked to original sources
PubMed1991

[Comparative studies on the repetitive DNA sequences of diploid and triploid forms of Paragonimus westermani by restriction endonuclease and Southern blotting].

Restriction enzyme digestion of total genomic DNA of two chromosomes forms of Paragonimus westermani showed the presence of homologous highly repeated DNA in both diploid and triploid forms. Southern blotting analysis provided further evidence that the distribution of restriction enzyme sites (with 3 enzymes) on repetitive sequence of DNA of both forms were similar. However, with Pstl, Ddel, HaeIII and HpaII, their polymorphism revealed differences which were also found in each form tested separately with the hybridization technique. The present study, at the molecular level, supports the previously reported biological and biochemical results that they might be considered as different isolates or forms. It is suggested that PstI, DdeI, HaeIII and HpaII digestion pattern might be useful to distinguish the diploid from the triploid forms of Paragonimus westermani.

Animals↗
PubMed1990

The gene family encoding eggshell proteins of Schistosoma japonicum.

The four closely related genes encoding eggshell proteins in the human parasite Schistosoma japonicum are described. A cDNA and a genomic DNA library were constructed and members of the eggshell protein gene family isolated. The four genes in this family do not contain introns, and differ in organization and nucleotide sequence from the related set of genes in Schistosoma mansoni and Schistosoma haematobium. The coding sequences of two of the S. japonicum genes and their flanking regions were determined. Transcription start sites for these genes were shown by primer extension analysis to occur 47 and 50 nucleotides in front of the start codon. A female-specific component in nuclear extracts binds to a DNA fragment containing conserved sequences upstream of the transcription start sites. The deduced protein sequences of 207 and 212 amino acids are composed of 50% glycine with continuous glycine regions as long as 11 residues. In vitro translations of male and female RNAs revealed female-specific translation products, the sizes of which were consistent with the eggshell proteins.

Amino Acid Sequence↗
PubMed1989

Soluble proteins from Schistosoma mansoni and japonicum: a comparative biochemical and immunological analysis.

1. Soluble proteins were recovered from male Schistosoma mansoni after homogenization in Tris-HCl buffer containing 0.6 M KCl and 1.0% Triton X-100 followed by preparative electrophoresis on SDS-gel. 2. Polyclonal antibodies produced in mice against the soluble fraction were used in comparative analysis of S. mansoni and S. japonicum using immunoblots and immunoprecipitation of in vitro translated polypeptides. 3. Small molecular weight polypeptide (20-22 kdalton), identified by infected mouse serum (IMS) on immunoblots, was predominant in females and was not cross-reactive with heterologous IMS. 4. A 41-43 kdalton polypeptide which appeared as a doublet on immunoblots performed with polyclonal antiserum 4M, was predominant in males of both species although the polypeptides of S. mansoni showed slower electrophoretic mobility, and therefore the larger size (43 kdalton), than that of S. japonicum. 5. Comparison of fluorograms of the immunoprecipitates of in vitro translated polypeptides indicated that IMS of S. mansoni precipitated two, 30 and 94 kdalton, polypeptides while the IMS of S. japonicum identified at 72 kdalton polypeptide. Antisera 1M, 2M and 4M also showed similarities and differences in polypeptides of in vitro translation products of the two species of Schistosoma.

Animals↗
PubMed1988

The selective uptake of cholesterol by the rat tapeworm Hymenolepis diminuta (Cestoda).

1. The sterols of Hymenolepis diminuta are almost exclusively cholesterol or similar C-27 sterols; the free sterols of its environment (the lumen of the rat intestine) are cholesterol and various phytosterols. 2. During incubation of tapeworms with mixed micelles of taurocholate, glyceryl monooleate, and equimolar [3H]cholesterol and [14C]beta-sitosterol, the uptake of cholesterol is 40 times more rapid than the uptake of sitosterol. 3. Following uptake, the desorption of labeled sitosterol is six times more rapid than that of cholesterol. 4. We did not detect the esterification of absorbed sterols or the conversion of absorbed sitosterol of cholesterol. 5. The highly selective uptake of cholesterol and the moderately selective desorption of phytosterols can account for the selective accumulation of C-27 sterol by the tapeworm.

Animals↗
PubMed1988

Studies on the mechanism of cholesterol uptake by the rat tapeworm Hymenolepis diminuta (Cestoda).

1. With increasing cholesterol content in mixed micelles, the rate of cholesterol uptake by the tapeworm approaches a limiting, maximal value. 2. This uptake is inhibited only 32-40% by other sterols, but is not markedly dependent on medium pH or tapeworm energy metabolism. 3. The competitive exchange diffusion of absorbed [14C]cholesterol could not be demonstrated. 4. The above results partially support the hypothesis that the tapeworm absorbs cholesterol by a specific carrier-mediated process. 5. Cholesterol uptake is reduced when the capacity of the micellar phase of the medium is increased, suggesting that uptake involves the intermediate partitioning of sterol from micelles into the aqueous phase of the medium.

Absorption↗
PubMed1987

Actin and intermediate-sized filaments of the spines and cytoskeleton of Schistosoma mansoni.

The organization of spines and filaments in whole worms and cytoskeletal fractions of adult Schistosoma mansoni was investigated. The ultrastructure of the spine revealed a closely packed filamentous organization of 3.5- to 5.6-nm elements and electron-lucent areas. Spines were surrounded at the base by electron-dense bodies and membrane invaginations, and covered at the tip by the syncytial surface membrane. Filaments, 7.5-11.1 nm in diameter, were closely associated with the base of the spines, between muscles, near mitochondria or nuclei, and in spaces of the subtegument. Cytoskeletal fractions prepared by homogenizing adults in Tris-HCl buffer, containing 0.6 M KCl and 1.0% Triton X-100, represented 19%-25% and 32%-38% of wet weight of males and females, respectively. The fractions contained nuclei, spines, 8 to 11 nm filaments, myofibrils, and granules. Vitellaria and egg shells were abundant in fractions from females. Six polypeptides with estimated molecular weights of 130, 96, 84, 78, 74 and 43 kdaltons were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as the major components of the cytoskeleton. Monoclonal antibody to chicken actin (MAA) was localized predominantly in surface spines and tubercles of adult schistosomes by the indirect immunofluorescence test, while immune serum from infected mice reacted less specifically with the tegument. A 43-kdalton polypeptide with electrophoretic mobility identical to that of vertebrate actin, identified in cytoskeletal and tegumental fractions of adult worms, reacted positively with MAA on immunoblotting.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗
PubMed1985

tris(Hydroxymethyl)aminomethane: an artifact detected as an aminotetrose by gas chromatography/mass spectrometry.

The monosaccharide content of the ethanol-soluble moiety of crude polysaccharide fractions of the tapeworm Hymenolepis diminuta and the blood fluke Schistosoma mansoni was investigated by gas-liquid chromatography of alditol acetate derivatives. A prominent, unusual peak was found, and mass spectrometry suggested identification as an aminotetrose, a four-carbon aminosugar reported only once in the past 15 years [D. A. Cumming, C. G. Hellerquist, and O. Touster (1981) J. Biol. Chem. 256, 7723-7726]. The unknown molecule was found to be tris(hydroxymethyl)aminomethane (Tris), whose acetylated derivative has a mass spectrum identical to that of an aminotetrose. The source of the Tris was traced to buffers used in conjunction with polysaccharide isolation.

Amino Sugars↗
PubMed1985

Biosynthesis of polyisoprenoid lipids in the rat tapeworm Hymenolepis diminuta.

The possible occurrence of isoprenoid lipids in the tapeworm, Hymenolepis diminuta, was investigated by analytic and biosynthetic methods. Two-dimensional thin layer chromatography (TLC) resolved the worm's non-saponifiable lipids into cholesterol, farnesol, and several unknown compounds, two of which migrated with dolichol standards on TLC and reacted with phthalic anhydride, a probe for alcohols; the major compound also exhibited a mass spectrum very similar to that of a dolichol standard. A third unknown compound separable by TLC, apparently a quinone, was intrinsically red, was decolorized by treatment with sodium dithionite and migrated on TLC in a more polar position than either ubiquinone-50 or vitamin K1. All three compounds, as well as farnesol, were labelled when worms were incubated with [14C]-mevalonolactone, suggesting that they are endogenous isoprenoids.

Animals↗
PubMed1985

Isolation and characterization of glycosaminoglycans from Schistosoma mansoni.

Tegumental tissues of paired adult Schistosoma mansoni were removed by treatment with Triton X-100 and recovered by centrifugation. The chloroform-methanol insoluble residues of this isolated tegumental fraction and of the denuded carcasses were analysed for glycosaminoglycan (GAG) and sialic acid contents. Treatment with GAG-specific enzymes followed by electrophoretic analysis showed that both the carcass and tegument contained heparin and/or heparan sulfate, chondroitin sulfate and hyaluronic acid. All these except hyaluronic acid were present in the tegumental fraction. Based on uronic acid content, about 73% of the total GAG was in the tegumental membrane, 15% in the tegmental matrix and the remaining 12% was in the carcass. The presence of heparin-like polysaccharide may present entrapment of the schistosoma by the hosts' blood-clotting process.

Animals↗
PubMed1985

A comparison of Texan and Hawaiian strains of the avian eyefluke, philophthalmus gralli, with a cautionary note on the importation of exotic animals.

Philophthalmus gralli (Mathis and Leger, 1910) was introduced into the San Antonio, Texas area within the last 25-30 years from an unknown foreign source. Strains of P. gralli originally from Texas and Hawaii were compared for differences in morphology, growth patterns, mating compatibility, and isozyme mobilities. Metacercarial cysts of the 2 strains were compared for viability after storage at room temperature. Adult stages of the 2 strains were indistinguishable based on sucker ratios, vitellaria, and egg sizes. In single- and multiple-worm infections, both strains exhibited similar growth patterns when reared in chickens. Adults of the 2 strains, when transplanted in concurrent infections, readily cross-inseminated. Isozyme mobilities of 5 enzymes were identical in all adult worms examined from both strains. After 3 days, metacercarial cysts from both strains rapidly lost their ability to excyst. The cysts of the Texan strain remained viable for 4 days longer than the Hawaiian strain, although excystment rates were low during that period. The evolutionary implications of this imported species are discussed.

Animals↗
PubMed1979

In vitro activation and behavior of the ameboid sperm of Ascaris suum (Nematoda).

A system is described for the study of activation and motility of Ascaris spermatozoa in vitro. Activation was accomplished by addition of the sperm-activating substances (SAS), extracted from the male accessory gland, to cells incubated in phosphate-buffered saline (pH 7.4) at 37-39 degrees C under anaerobic conditions (95% N2, 5% CO2). Activation is characterized by a change from spherical to ameboid shape with coalescence of the refringent granules. The normal ameboid spermatozoa bear several stubby and needle-like filopodia at the lamellipodial margin. Within the lamellipodium are bundles of microfilament-like structures extending toward the pseudopodial membrane and concentrating within the needle-like filopodia. These filopodia exhibit a pendulous, sweeping motion with subsequent retraction and disappearence within the main lamellipodium. Membranes of the ameboid cells interact at the pseudopodial regions with partial fusion, as suggested by apparent membrane breakdown between interdigitating portions of the pseudopodia. Activation is complete in 5-15 min, is totally inhibited at 4 degrees C and/or by an atmospheric environment, but can be reinitiated by transfer to anaerobic conditions at 22-39 degrees C. Activation also requires favorable pH (6.8-8.7) and continual exposure to sufficiently high sodium concentrations (134-154 mM), i.e., lowering of sodium concentration to 10 mM causes irreversible inactivation. Sodium may be replaced by potassium or lithium but not by Tris or sucrose. Proteinases (10 microgram/ml) can act as activators even though SAS lack detectable proteolytic activity against azoalbumin, azocasein, TAME and BTEE and SAS activation was not inhibited by TLCK or soybean trypsin inhibitor.

Animals↗
PubMed1977

Methoxyflurane hepatitis.

A veterinarian's assistant who sniffed methoxyflurane as a euphoriant developed fulminant hepatitis and died of hepatic failure. The abuse of fluorinated anesthetics has been reported and may be more frequent than is commonly believed. It is suggested that fluorinated anesthetics should be considered as a causative agent in a case of fulminant hepatitis, especially in patients who have easy access to such drugs.

Adult↗
PubMed1977

A simple method of obtaining an enriched fraction of tegumental brush border from Hymenolepis diminuta.

A method for isolating an enriched preparation of tegumental brush border from the tapeworm, Hymenolepis diminuta, is described. Combining incubation of whole tapeworms in Krebs-Ringer/tris-maleate solution containing a hemolytic saponin, low shear-force agitation, and differential centrifugation, a pellet is obtained at 2,500 g which contains a significant concentration of surface brush border. The content of brush border in this fraction is identified by the presence of numerous microvilli, increased specific radioactivity after surface tagging with 3H-Concanavalin A, and relatively little mitochondrial contamination (succinic dehydrogenase). Based on morphological criteria, fractions sedimenting with greater force contain dense vesicles and mitochondria from the outer portion of the tegument.

Cestoda↗
PubMed1977

Lipids from subcellular fractions of the tegument of Hymenolepis diminuta.

Lipids comprised 37% and 22.1%, respectively, of the day weights of brush border- and vesicle-rich fractions separated by differential centrifugation of isolated H. diminuta tegument. Neutral lipids of both fractions were rich in cholesterol, but also contained small amounts of glycerides, sterol esters, and (in brush borders) free fatty acids. Phosphatidyl ethanolamine was the most prevalent polar lipid in both fractions, and was particularly abundant (63.4% of total polar lipids) in vesicles; sphingomyelin, not previously reported from H. diminuta, was also present. Polar lipids of both tegumental fractions resembled each other but differed from whole worm polar lipids in fatty acid composition. Tegumental polar lipids contained lower levels of long-chain, polyunsaturated fatty acids than reported for corresponding lipids of whole worms.

Cestoda↗