Trichinella spiralis: Comparison with an Arctic isolate

The muscle phase of Trichinella spiralis and of Trichinella sp. isolated in the Arctic was compared in experimental and wild animals. Reproductive capacity indices (RCI) of the Trichinella sp. isolate were significantly lower in laboratory rodents but were similar to T. spiralis in wild rodents. Sprague-Dawley rats were the most refractory to the Trichinella sp. isolate of all laboratory rodents. Outbred strains of mice were more susceptible to both T. spiralis and the Trichinella sp. isolate than inbred strains of mice. T. spiralis muscle larvae survived longer in mice and the survival of both T. spiralis and the Trichinella sp. isolate larvae was higher in female mice. While single pair interbreeding experiments showed reproductive isolation between T. spiralis and the Trichinella sp. isolate, multiple pair and transplant breeding experiments showed reproductive compatibility. Male and female infective larvae of T. spiralis and the Trichinella sp. isolate differed morphometrically, but a convergence in size of worms was observed after prolonged passages of the parasites in mice. Passaging history of the isolate and host species was found to have a significant effect on Trichinella morphology. It is proposed that the Trichinella sp. isolate is a physiological variant of T. spiralis and not a distinct species.     

Analysis of mitochondrial DNA from somatic hybrid cell lines of Saccharum officinarum (sugarcane) and Pennisetum americanum (pearl millet)

Mitochondrial DNA (mtDNA) from cell suspension cultures of two intergeneric somatic hybrids of Pennisetum americanum (pearl millet) + Saccharum officinarum (sugarcane) was examined by restriction endonuclease digestion and hybridization with sorghum mtDNA cosmids. The mtDNA of one somatic hybrid was indistinguishable from that of pearl millet, while the second exhibited a combination of parental mtDNAs, suggesting mitochondrial fusion. Several novel, possibly recombinant, mtDNA restriction fragments were detected in this hybrid, which may have resulted from intergenmic recombination.Florida Agriculture Experiment Station Journal Series No: 8090.     

Estrogen sulfotransferase of mouse placenta: behaviour and characteristics during partial purification

Mouse placental estrogen sulfotransferase (ST) was partially purified by fast protein liquid chromatography (FPLC) gel filtration in combination with FPLC anion exchange. Owing to the highly unstable nature of the enzyme, large increases in specific activity were not obtained. Storage of the ST in the presence of thiol groups at -20 degrees C stabilized the enzyme considerably. Forty-three percent of the cytosolic ST was bound to an Affi-Gel blue column and eluted as a broad peak at approximately 0.8 M NaCl. The use of the latter procedure, in combination with FPLC gel filtration, did not increase the specific activity substantially. Larger increases in specific activity were obtained using agarose-hexane-adenosine-3',5'-diphosphate affinity chromatography. The bound ST activity was eluted under a single peak at 1 mM ADP. Increases in specific activity following use of this column averaged 54-fold but could reach 90-fold. Attempts at further purification of this material resulted in low recovery and decreased specific activity. Velocity versus substrate concentration curves show that estrone and particularly estradiol inhibit the partially purified mouse placental sulfotransferase above 0.1-0.25 microM substrate concentrations.     

Gall stones in sickle cell disease in the United Kingdom.

The prevalence of gall stones was studied prospectively by abdominal ultrasound examination in 131 patients with sickle cell disease aged 10-65 years. Of 95 patients with homozygous sickle cell disease, 55 (58%) had gall stones or had had a cholecystectomy. Gall stones were present in four out of 24 (17%) patients with haemoglobin S + C disease and two out of 12 (17%) with haemoglobin S beta thalassaemia. The presence of gall stones was not related to sex, geographical origin, or haematological variables and was not associated with abnormal results of liver function tests. Symptoms typical of biliary colic were reported by 32 out of 47 adult patients with gall stones, and cholecystitis or cholestasis was diagnosed in 18. Cholecystectomy was performed in 29 patients with good relief of symptoms in most cases. Postoperative complications were common, occurring in 10 of the 28 patients who could be evaluated, but not generally serious; they were considerably lessened by a preoperative exchange transfusion that reduced the haemoglobin S concentration to below 40%. It is suggested that all patients with sickle cell disease should be screened for gall stones and that elective cholecystectomy should be performed in those with symptoms or complications.