Multiple mitochondrial viruses in an isolate of the Dutch Elm disease fungus Ophiostoma novo-ulmi.

The nucleotide sequences of three mitochondrial virus double-stranded (ds) RNAs, RNA-4 (2599 nucleotides), RNA-5 (2474 nucleotides), and RNA-6 (2343 nucleotides), in a diseased isolate Log1/3-8d2 (Ld) of the Dutch elm disease fungus Ophiostoma novo-ulmi have been determined. All these RNAs are A-U-rich (71-73% A + U residues). Using the fungal mitochondrial genetic code in which UGA codes for tryptophan, the positive-strand of each of RNAs 4, 5, and 6 contains a single open reading frame (ORF) with the potential to encode a protein of 783, 729, and 695 amino acids, respectively, all of which contain conserved motifs characteristic of RNA-dependent RNA polymerases (RdRps). Sequence comparisons showed that these RNAs are related to each other and to a previously characterized RNA, RNA-3a, from the same O. novo-ulmi isolate, especially within the RdRp-like motifs. However, the overall RNA nucleotide and RdRp amino acid sequence identities were relatively low (43-55% and 20-32%, respectively). The 5'- and 3'-terminal sequences of these RNAs are different, but they can all be folded into potentially stable stem-loop structures. Those of RNA-4 and RNA-6 have inverted complementarity, potentially forming panhandle structures. Their molecular and biological properties indicate that RNAs 3a, 4, 5, and 6 are the genomes of four different viruses, which replicate independently in the same cell. These four viruses are also related to a mitochondrial RNA virus from another fungus, Cryphonectria parasitica, recently designated the type species of the Mitovirus genus of the Narnaviridae family, and to a virus from the fungus Rhizoctonia solani. It is proposed that the four O. novo-ulmi mitochondrial viruses are assigned to the Mitovirus genus and designated O. novo-ulmi mitovirus (OnuMV) 3a-Ld, 4-Ld, 5-Ld, and 6-Ld, respectively. Northern blot analysis indicated that O. novo-ulmi Ld nucleic acid extracts contain more single-stranded (ss, positive-stranded) RNA than dsRNA for all three newly described mitoviruses. O. novo-ulmi RNA-7, previously believed to be a satellite-like RNA, is shown to be a defective RNA, derived from OnuMV4-Ld RNA by multiple internal deletions. OnuMV4-Ld is therefore the helper virus for the replication of both RNA-7 and another defective RNA, RNA-10. Sequence comparisons indicate that RNA-10 could be derived from RNA-7, as previously suggested, or derived directly from RNA-4.

Fetal monitoring--midwifery attitudes.

OBJECTIVE: to survey midwives' attitudes and practices related to intrapartum fetal monitoring. DESIGN: descriptive correlational study. SETTING: regional and district maternity unit and related community area within one health authority. PARTICIPANTS: all midwives were invited to participate. Two hundred and forty two questionnaires were administered and 117 were returned (48% response rate). MEASUREMENTS AND FINDINGS: in the questionnaire information was collected on professional/demographic details, education and practices related to intrapartum fetal monitoring, together with a 20-item attitude scale which encompassed attitudes towards fetal monitoring and related issues. As expected, the findings suggest that midwives' preferred methods of fetal monitoring varied with the client's risk category. However, midwife preference did not necessarily match actual choice of method. There are many factors influencing choice, not least of which is confidence in ability. Significant differences were found between midwives. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: the findings highlight some of the issues relating to individual confidence. 97% of the midwives felt they would benefit from in-service training in CTG interpretation. The findings support the development of continuing in service education programmes for midwives.