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Biomedical subjects

B Fried

Publications and source records attributed to B Fried.

At least 181 records · Page 10Linked to original sources
PubMed1985

The uptake, localization and transfer of [4-14C]cholesterol in Schistosoma mansoni males and females maintained in vitro.

Schistosoma mansoni male and female adults incorporated [4-14C]cholesterol in vitro. Males incorporated about three times more cholesterol than females. The major sites of cholesterol deposition in males were the tegument and parenchyma. The tegument and vitelline glands were the primary sites of cholesterol accumulation in females. In males, dorsal tegument showed greater cholesterol uptake than ventral tegument. Radiolabelled males and females transferred cholesterol to unlabelled members of the opposite sex.

Animals↗
PubMed1985

Schistosoma haematobium: neutral lipid composition and release by adults maintained in vitro.

Thin-layer chromatographic analyses showed that the major neutral lipid fractions of whole-worm extracts of male and female adult Schistosoma haematobium were free sterols, triacylglycerols and sterol esters. Worm-free incubates of adult worm-pairs contained free sterols only. The major fractions of worm-free incubates from separated worms were free fatty acids and free sterols; traces of triacylglycerols and sterol esters were also detected. Females incubated in a group of ten released more free fatty acids than ten incubated singly. Males incubated singly released more free sterols than a similar number incubated in a group. Females released more free sterols than males.

Animals↗
PubMed1984

Further studies on in vitro pairing of Echinostoma revolutum (Trematoda) adults.

Various factors that influence in vitro pairing of Echinostoma revolutum adults were studied. More worms paired in Locke's, Ringer's, and 0.85% NaCl solutions than in the defined medium NCTC 135. Also, more pairing occurred at 39 or 43 degrees C than at 35 degrees C. Echinostomes placed 1, 3, or 5 cm apart in 5.5 cm diameter Petri dishes as well as those placed 2, 4, or 6 cm apart in 8.5 cm diameter Petri dishes paired; however, worms placed 8 cm apart in the latter dishes did not. Individuals maintained in Locke's solution at 20 or 39 degrees C for 1 h after having been removed from the chicks paired less frequently than those used for experiments immediately after their removal from chicks. Worms showed more pairing in fresh Locke's solution than in this solution preconditioned by excretory-secretory products of E. revolutum. Scanning electron microscopy revealed no differences between the tegument of fresh worms and of those maintained under experimental conditions for 2 h at 39 degrees C.

Animals↗
PubMed1984

Histochemical and thin-layer chromatographic analyses of neutral lipids in various host sites infected with Leucochloridiomorpha constantiae (Trematoda).

Histochemical and thin-layer chromatographic (TLC) analyses were used to study the effects of trematode parasitism by Leucochloridiomorpha constantiae on sites occupied by this fluke. Oil Red O staining showed that the epithelium in infected sites, i.e., bursa of Fabricius of the domestic chicken, chorionic ectoderm of the chick embryo, and uterus of Campeloma decisum snails, was positive for neutral lipids. TLC showed that infection in the bursa caused an increase in free fatty acids and triglycerides in that organ; infection of the chick chorioallantois caused a decrease in free sterols and sterol esters in the membrane; the uterus of infected snails showed elevated free sterols.

Allantoin↗
PubMed1984

Infectivity, growth and development of Echinostoma revolutum (Trematoda) in the domestic chick.

Infectivity, growth and development were studied in 23 one-day-old domestic chicks each fed 25 pre-selected metacercarial cysts of Echinostoma revolutum. All chicks were infected at necropsy one to 44 days post-exposure with one to 18 flukes/chick. From the 575 cysts fed to chicks, 145 (25%) flukes were recovered from the ileum, caeca, rectum-cloaca and bursa of Fabricius. Length measurements on 113 uncurled flukes fixed in hot alcohol-formalin-acetic acid showed that worms grew slowly to 1.0 mm by day 3, rapidly to 6 mm by day 14, and less rapidly to 9 mm by day 36. Worms became ovigerous by day 9. As worms aged in the chick, the body length increased relative to the width, the acetabulum shifted more anteriad and the size of the excretory bladder increased.

Animals↗
PubMed1984

Long repair replication patches are produced by the short-patch pathway in a uvrD252 (recL152) mutant of Escherichia coli K-12.

The uvrD252 mutation leads to increased UV sensitivity, diminished dimer excision and host cell reactivation capacity, and an increase in the average patch size after repair replication. A recA56 uvrD252 double mutant was far more resistant to UV than was a recA56 uvrB5 double mutant. Its host cell reactivation capacity was identical to that of uvrD252 single mutant and was far greater than that of the uvrB5 single mutant. The strain showed no Weigle reactivation. From these results, we concluded that the double mutant has no inducible DNA repair (including long-patch excision repair) but retains dimer excision capabilities comparable to the uvrD252 single mutant. It appears, therefore, that the long patches detected in the uvrD mutant were not identical to the recA-dependent patches seen in wild-type cells.

DNA Repair↗
PubMed1984

Comparative pathologic features and development of Sphaeridiotrema globulus (Trematoda) infections in the mute swan and domestic chicken and chicken chorioallantois.

The natural infection of Sphaeridiotrema globulus in the mute swan and the experimental infection in the chicken resulted in an ulcerative hemorrhagic enteritis. Swans and chickens died from the resultant blood loss. Culturing of the parasite on the chorioallantoic membrane of the chicken egg resulted in hemorrhage and a cellular response of the chorioallantois to the trematode. Experimental infections in the domestic chicken and chicken embryo can be of use for the study of ulcerative hemorrhagic enteritis produced by the trematode, pathologic features, identification of the metacercaria to the adult, and developmental aspects of the parasite.

Animal Population Groups↗
PubMed1983

Schistosoma mansoni: adult worm chemoattraction with barriers of specific molecular weight exclusions.

Chemoattraction studies were done with Schistosoma mansoni adults from mice. To test for attraction or repulsion, some worm pairs were separated mechanically and the individuals placed in polycarbonate chambers. Experiments were done at 37 C and chambers contained dialysis tube chimneys. In all cases, heterosexual attraction occurred when one worm, but not two worms, were placed in the chimneys. Unperforated chimneys with specific molecular weight (Mr) exclusions were compared with perforated chimneys to study heterosexual attraction. Attraction was similar in designs using perforated chimneys and those with 50,000 and 12,000 Mr exclusions, but none was seen in chimney designs with 1000 Mr exclusions.

Animals↗