PubMed Health⌕ Search

Biomedical subjects

S Higgs

Publications and source records attributed to S Higgs.

60 records · Page 4Linked to original sources
PubMed1990

RNA probes detect nucleotide sequence homology between members of two different nairovirus serogroups.

Cloned cDNA derived from the small (S) and medium (M) genomic RNA segments of Dugbe (DUG) virus, isolate ArD44313, a member of the Nairobi sheep disease (NSD) serogroup of nairoviruses (family, Bunyaviridae) was used to prepare 32P-labelled DNA and RNA probes. The S and M segments of six isolates of DUG virus all hybridised to both DNA and RNA probes, although the M segment of isolate KT281/75 reacted only weakly. Of nine other nairoviruses tested, representing all the six other serogroups within the Nairovirus genus, none hybridised to the DNA probes. However, under conditions of low stringency, the DUG S and M RNA probes hybridised to the respective S and M segments of Ganjam (GAN) virus (another member of the NSD serogroup). The DUG S RNA probe also hybridised to the S segments of Crimean-Congo haemorrhagic fever (CCHF) virus and Hazara (HAZ) virus (members of the CCHF serogroup). The indicated sequence relationships between DUG, GAN, CCHF and HAZ viruses show that the NSD serogroup is more closely related to members of the CCHF serogroup than it is to nairoviruses of the other five serogroups.

Animals↗
PubMed1989

Eimeria species infecting wood mice (genus Apodemus) and the transfer of two species to Mus musculus.

Characteristics of four species of Eimeria isolated from Apodemus sylvaticus are described. From oocyst morphology, three are identified as E. apionodes, E. hungaryensis and E. uptoni, the fourth being unnamed. Cloning demonstrated that oocysts of E. hungaryensis were polymorphic. Previous literature relating to the taxonomy is discussed and discrepancies outlined. Species isolated from A. sylvaticus were not transmissible to Clethrionomys glareolus, but both E. hungaryensis and E. apionodes have been passaged through immunosuppressed laboratory mice, the former species more than 16 times. In both A. sylvaticus and immunosuppressed laboratory mice, endogenous development of E. hungaryensis occurred mainly in enterocytes near the tips of the villi in the first half of the small intestine, with a few parasites in the rest of the small intestine and into the large intestine. The pre-patent period was 2 days in both hosts but oocyst output was higher in the natural hosts. E. apionodes parasitized enterocytes on the sides or at the base of the villi, mainly in the last 90% of the small intestine with a few parasites in the large intestine. The pre-patent period was 7 days. Parasites, probably E. hungaryensis and E. apionodes, were also isolated from A. flavicollis.

Animals↗
PubMed1989

Use of a monoclonal antibody specific for wild-type yellow fever virus to identify a wild-type antigenic variant in 17D vaccine pools.

Monoclonal antibodies (MAbs) against the Asibi wild-type strain of yellow fever (YF) virus were prepared and characterized. One of the MAbs (designated MAb 117) was shown, by cross-immunofluorescence tests with flaviviruses, to be specific for wildtype YF virus. This MAb was used in indirect immunofluorescence tests to identify wild-type antigenic variants in several different YF vaccine pools. Simultaneously, a vaccine-specific MAb prepared previously (MAb 864) was used to identify YF strain 17D vaccine type variants in the wild-type Asibi virus preparation. One variant, isolated by plaque purification from a 17D vaccine pool, possessed the wild-type epitope and was neurovirulent in infant mice whereas other variants, lacking the wild-type epitope but with vaccine-specific epitopes (identified by MAb 411), were avirulent in infant mice. Avirulent variants were able to infect mice and induce antibody. Virus-specific antigen was still detected in the brains of these mice 4 weeks after inoculation, suggesting that persistent infections were developing. These results to the potential risk of selection of wild-type variants in YF vaccine preparations. They also point to the potential risk of selection of wild-type variants in YF vaccine preparations and re-emphasize the need for modernization of techniques and more effective control measures to be taken during the production of YF vaccine.

Animals↗
PubMed1988

Laboratory studies with clones of Eimeria hungaryensis, a parasite of the wood mouse Apodemus sylvaticus.

Doses from 1 to 10(5) sporulated oocysts of a cloned strain of Eimeria hungaryensis were used to infect laboratory-reared, coccidia-free wood mice (Apodemus sylvaticus). Total oocyst production, reproductive indices (output/dose) and daily patterns of oocyst production were compared. At doses of 10(2) oocysts or less, observed yields exceeded expected yields calculated using details of endogenous stages. At doses above 10(2) oocysts, the converse occurred. From infections initiated with 10(2) oocysts, total outputs were not significantly different in male and female wood mice, host age had no apparent effect and repeated infections, at 10-day intervals, of both sexes, resulted in progressive decreases in output at each successive infection, suggesting development of resistance.

Age Factors↗
PubMed1980

Detection of alpha thalassaemia in Negro infants.

A prospective study of 2191 Negro infants in Jamaica showed that approximately 7% of them had detectable levels of Hb Bart's (gamma 4) in the neonatal period. The red cell indices, globin chain biosynthesis and restriction endonuclease mapping of DNA from these infants were used to determine the significance of Hb Bart's at birth. The results indicate that the genotypes alpha alpha/alpha alpha, -- alpha/alpha alpha and -- alpha/ -- alpha are associated with 0%, 0.1-2%, and greater than 2% Hb Bart's respectively. Although trace amounts of Hb Bart's may be associated with the genotype -- alpha/alpha alpha this is not always the case and therefore haemoglobin analysis in the neonatal period cannot be used to diagnose this genotype with any certainty.

Black People↗