Sequence diversity of human rotavirus strains investigated by northern blot hybridization analysis.

Rotavirus genomic RNAs, derived from a series of human isolates that exhibit variability in the pattern of migration of the double-stranded RNA on polyacrylamide gels, were transferred to diazobenzyloxymethyl paper, and their sequence diversity was investigated. Hybridization of cDNA probes prepared from the 11 segments of rotavirus RNA indicated that considerable sequence diversity exists among these viruses. Under conditions of both low and high stringency, hybridization analysis of virus collected between 1975 and 1980 suggested that the variation among rotavirus strains may have occurred by a process involving both "drift" and "shift" in the sequence of the rotavirus genomic segments.     

INCORPORATION OF TRITIATED THYMIDINE INTO THE SKIN AND HAIR FOLLICLES

Diurnal fluctuations in incorporation of tritiated uridine and tritiated thymidine are reported for full thickness skin and its two proliferative populations, the epidermal basal layer and the hair follicle germ or matrix. Recently developed techniques whereby these two populations can be studied independently were utilized. Resting (unplucked) skin and skin in the middle of the hair growth cycle (10 days after plucking) was studied. the diurnal fluctuations differed at these two stages of the hair cycle. Generally a single minimum level of activity was observed shortly after the beginning of the dark period of the day, i.e. after 18.00 hours.     

Objective assessment of treatment response in hirsutism

A simple photographic technique was used to assess the objective response of hirsute women to treatment with cyproterone acetate (CA). The skin in front of the left ear was shaved and photographs taken immediately and after 1 week, and hair growth per week estimated by averaging the length of 20 hairs in the magnified photographs. The precision, repeatability and patient acceptance of the method were found to be satisfactory. Basal hair growth rates were 2.28 +/- 0.4 mm/week (mean +/- SD, n = 34) and showed a significant correlation with hirsutism scores derived from a standard physician-rated scale. During therapy with CA the mean (+/- SD) improvement in hair growth rate was 19 +/- 13%, whereas physician-rated hirsutism scores improved by 33 +/- 20%. The reduction in hair growth rate showed no significant correlation with improvement assessed using subjective rating by either physician or patient. The greater improvement in physician-rated scores compared with hair growth rate assessment suggests that hair shaft width, colour and other factors may be as important as hair length when assessing treatment response.     

Serum digoxin in patients with thyroid disease.

Serum digoxin concentrations were measured by radioimmunoassay in 17 hyperthyroid and 16 hypothyroid patients after a seven-day course of oral digoxin. The significantly higher levels of serum digoxin in patients with hypothyroidism and lower levels in those with hyperthyroidism were closely related to the measured changes of glomerular filtration rate and digoxin serum half time in these two groups. Differences in serum digoxin concentration contribute to the altered sensitivity to digoxin shown by patients with thyroid disease.     

Identification of five major and two minor genotypes of varicella-zoster virus strains: a practical two-amplicon approach used to genotype clinical isolates in Australia and New Zealand

Whole genome phylogenetic analysis in this study resolved a total of five major genotypes among the 22 varicella-zoster virus (VZV) strains or isolates for which complete genomic sequences are available. Consistent with earlier publications we have designated these genotypes European 1 (E1), European 2 (E2), Japanese (J), mosaic 1 (M1), and mosaic 2 (M2). Single nucleotide polymorphism (SNP) analysis performed in a whole-genome alignment revealed that VZV isolates of all five genotypes can be accurately genotyped using SNPs from two amplicons: open reading frame 22 (ORF22) and either ORF21 or ORF50. This modified approach identifies all of the genotypes observed using any of the published genotyping protocols. Of 165 clinical varicella and zoster isolates from Australia and New Zealand typed using this approach, 67 of 127 eastern Australian isolates were E1, 30 were E2, 16 were J, 10 were M1, and 4 were M2; 25 of 38 New Zealand isolates were E1, 8 were E2, and 5 were M1. VZV strain diversity in eastern Australia is thus broader than has been described for any other region, including Europe, Africa, and North America. J strains were far more prevalent than previously observed in countries other than Japan. Two-amplicon typing was in complete accord with genotypes derived using SNP in multiple ORFs (ORFs 1, 21, 22, 38, 50, 54, and 62). Two additional minor genotypes, M3 and M4, could also be resolved using two-amplicon typing.     

Apparent competition between two species of aphid via the fungal pathogen Erynia neoaphidis and its interaction with the aphid parasitoid Aphidius ervi

Abstract 1. Motivated by a community study on aphids and their fungal pathogens, three hypotheses were tested experimentally to investigate the influence of the fungal pathogen, Erynia neoaphidis Remaudière and Hennebert, on aphid population and community ecology.
2. Field experiments were performed in 2 years to test whether two susceptible aphid species on different host plants might interact through the shared fungal pathogen. No strong pathogen-mediated indirect interactions (apparent competition) between populations of pea aphid Acyrthosiphon pisum Harris and nettle aphid Microlophium carnosum Buckton were detected.
3. In the first of the field experiments, pea aphids exposed to the fungus showed a weak tendency to produce more winged dispersal morphs than control populations not exposed to the fungus. In a laboratory test, however, no support was found for the hypothesis that the presence of volatiles from fungus-infected cadavers promotes production of winged offspring.
4. The response of the pea aphid parasitoid Aphidius ervi Halliday to colonies containing hosts infected 1 and 3 days previously was assessed. Wasps initiated fewer attacks on 1-day-old infected colonies than on healthy colonies, with the numbers on 3-day-old fungus-infected colonies intermediate.     

High-level variability in the ORF-K1 membrane protein gene at the left end of the Kaposi's sarcoma-associated herpesvirus genome defines four major virus subtypes and multiple variants or clades in different human populations

Infection with Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV8) is common in certain parts of Africa, the Middle East, and the Mediterranean, but is rare elsewhere, except in AIDS patients. Nevertheless, HHV8 DNA is found consistently in nearly all classical, endemic, transplant and AIDS-associated KS lesions as well as in some rare AIDS-associated lymphomas. The concept that HHV8 genomes fall into several distinct subgroups has been confirmed and refined by PCR DNA sequence analysis of the ORF-K1 gene encoding a highly variable glycoprotein related to the immunoglobulin receptor family that maps at the extreme left-hand end of the HHV-8 genome. Among more than 60 different tumor samples from the United States, central Africa, Saudi Arabia, Taiwan, and New Zealand, amino acid substitutions were found at a total of 62% of the 289 amino acid positions. These variations defined four major subtypes and 13 distinct variants or clades similar to those found for the HIV ENV protein. The B and D subtype ORF-K1 proteins differ from the A and C subtypes by 30 and 24%, respectively, whereas A and C differ from each other by 15%. In all cases tested, multiple samples from the same patient were identical. Examples of the B subtype were found almost exclusively in KS patients from Africa or of African heritage, whereas the rare D subtypes were found only in KS patients of Pacific Island heritage. In contrast, C subtypes were found predominantly in classic KS and in iatrogenic and AIDS KS in the Middle East and Asia, whereas U.S. AIDS KS samples were primarily A1, A4, and C3 variants. We conclude that this unusually high diversity, in which 85% of the nucleotide changes lead to amino acid changes, reflects some unknown powerful biological selection process that has been acting preferentially on this early lytic cycle membrane signalling protein. Two distinct levels of ORF-K1 variability are recognizable. Subtype-specific variability indicative of long-term evolutionary divergence is both spread throughout the protein as well as concentrated within two 40-amino-acid extracellular domain variable regions (VR1 and VR2), whereas intratypic variability localizes predominantly within a single 25-amino-acid hypervariable Cys bridge loop and apparently represents much more recent changes that have occurred even within specific clades. In contrast, numerous extracellular domain glycosylation sites and Cys bridge residues as well as the ITAM motif in the cytoplasmic domain are fully conserved. Overall, we suggest that rather than being a newly acquired human pathogen, HHV8 is an ancient human virus that is preferentially transmitted in a familial fashion and is difficult to transmit horizontally in the absence of immunosuppression. The division into the four major HHV8 subgroups is probably the result of isolation and founder effects associated with the history of migration of modern human populations out of Africa over the past 35,000 to 60,000 years.     

INCORPORATION OF TRITIATED THYMIDINE INTO THE SKIN AND HAIR FOLLICLES

The incorporation of tritiated thymidine into the skin has been studied after the initiation of new hair growth by plucking. Techniques are described whereby the incorporation into hair follicles and into the basal layer of the epidermis can be studied independently. Fluctuations are observed in the levels of incorporation in both cell populations through the hair growth cycle. These fluctuations show great regularity. the early fluctuations have been attributed to synchronous progression of cells through the cell division cycle. the significance of the fluctuations is discussed with particular reference to (I) possible persistence of cell cycle synchrony, (II) regulatory feedback mechanisms controlling DNA synthesis, perhaps through specific mitotic inhibitors, (III) the existence of G_o, G₁ and G₂ cell sub-populations.     

Extraction of rotavirus from human feces by treatment with lithium dodecyl sulfate.

A procedure has been developed for the isolation of rotavirus from human fecal specimens based on the resistance of the virus to treatment with cold 1% lithium dodecyl sulfate at neutral pH. A single detergent treatment of fecal material followed by low- and high-speed centrifugations yielded a virus suspension of sufficient purity for viral ribonucleic acid to be analyzed directly by electrophoresis on polyacrylamide gels.