Numerous length polymorphisms at short tandem repeats in human cytomegalovirus

We show the presence of numerous short tandem repeats in the human cytomegalovirus (HCMV) genome and assess their usefulness as molecular markers. The genome is shown to contain at least 24 microsatellite regions that exhibit length polymorphisms. Insertion-deletion polymorphisms at these short tandem repeats are common (80% of repeats examined are polymorphic among two laboratory strains and 10 clinical isolates). This is the first report of widespread microsatellite length polymorphism in a viral genome. Some regions are highly polymorphic: one was revealed by DNA sequencing to contain length variants at five closely linked sites, which combined resulted in 10 variants for this region among the 12 strains and isolates examined. This study not only provides a new molecular marker system for this virus but also extends our understanding of microsatellite polymorphism in two important ways. First, variable-length repeats in HCMV can be considerably shorter than polymorphic repeats previously found in other organisms. Second, highly variable microsatellite repeats are not confined to prokaryotes and eukaryotes, as previously assumed. This variation provides a useful marker system for distinguishing viral isolates, and similar markers are also likely to be found in other large-genome DNA viruses.

In vivo analysis of the domains of yeast Rvs167p suggests Rvs167p function is mediated through multiple protein interactions

Morphological changes during cell division in the yeast Saccharomyces cerevisiae are controlled by cell-cycle regulators. The Pcl-Pho85p kinase complex has been implicated in the regulation of the actin cytoskeleton at least in part through Rvs167p. Rvs167p consists of three domains called BAR, GPA, and SH3. Using a two-hybrid assay, we demonstrated that each region of Rvs167p participates in protein-protein interactions: the BAR domain bound the BAR domain of another Rvs167p protein and that of Rvs161p, the GPA region bound Pcl2p, and the SH3 domain bound Abp1p. We identified Rvs167p as a Las17p/Bee1p-interacting protein in a two-hybrid screen and showed that Las17p/Bee1p bound the SH3 domain of Rvs167p. We tested the extent to which the Rvs167p protein domains rescued phenotypes associated with deletion of RVS167: salt sensitivity, random budding, and endocytosis and sporulation defects. The BAR domain was sufficient for full or partial rescue of all rvs167 mutant phenotypes tested but not required for the sporulation defect for which the SH3 domain was also sufficient. Overexpression of Rvs167p inhibits cell growth. The BAR domain was essential for this inhibition and the SH3 domain had only a minor effect. Rvs167p may link the cell cycle regulator Pcl-Pho85p kinase and the actin cytoskeleton. We propose that Rvs167p is activated by phosphorylation in its GPA region by the Pcl-Pho85p kinase. Upon activation, Rvs167p enters a multiprotein complex, making critical contacts in its BAR domain and redundant or minor contacts with its SH3 domain.

A solitary maxillary central incisor treated orthodontically: a case report

The presentation of a solitary maxillary central incisor is reported and its association with other congenital abnormalities discussed. It is an important finding for dental health professionals, since it may indicate the presence of other significant midline congenital abnormalities. It may also indicate the presence of associated disorders that profoundly affect growth and development and which, once identified, may be treated.

Extending specialist palliative care to all?

How to extend palliative care services to all patients needing them is an issue currently exercising a range of bodies in contemporary Britain. This paper first considers the evidence regarding the needs of dying patients with long term conditions other than cancer and concludes that there is evidence to support their presumed need for palliative care. It then considers five potential barriers to extending specialist palliative care services to non-cancer patients in Britain. These are the skill base of current specialists in palliative care, difficulties in identifying candidates for specialist palliative care, the views of potential users of these services, resource implications and vested interests in present health service arrangements.

Survival and place of delivery following preterm birth: 1994-96

AIM

To compare the survival of premature infants, adjusted for disease severity, in different types of neonatal intensive care setting.

METHODS

A prospective observational study in the Trent Health Region was carried out of all infants born to resident mothers at or before 32 weeks of gestation between 1 January 1994 to 31 December 1996 inclusive. The 16 neonatal units in Trent were subdivided into five relatively large units which regularly took outside referrals and 11 smaller units which provided intensive care for a variable proportion (sometimes nearly 100%) of their local population. Data regarding obstetric management, neonatal care, and outcome were collected by independent neonatal nurses who visited the units on a regular basis. Survival rates were compared with an expected rate calculated using the Clinical Risk Index for Babies (CRIB). For either setting to be abnormally good or bad actual deaths had to exceed the 95% confidence interval of the CRIB estimate.

RESULTS

Actual survival rates for infants < or = 32 weeks gestation and for the group of babies < or = 28 weeks gestation fell within the 95% confidence interval of the rate predicted by CRIB for both the larger referral units and the smaller district units. Similarly, compared with the CRIB prediction, infants transferred in utero or postnatally were not adversely affected in terms of the number who died.

CONCLUSION

Previous results from this geographical population, showing that survival of babies < or = 28 weeks gestation was better when their care was provided by referral units, are no longer sustained. Significant changes to the neonatal services over time make the current results plausible. However, the new structure poses potential threats to the teaching, training, and research base of the neonatal service as a whole.

Congenital sinus of the upper lip. A case report

A case report of a congenital midline sinus in the upper lip of a 13-year-old girl is presented. Theories proposed regarding the aetiology of this rare anomaly are discussed.

Ophthalmic chloramphenicol: a review of the literature

The safety of ophthalmic chloramphenicol has been under review in the UK since 1995, when a letter in the British Medical Journal suggested that its use should be discontinued. The writers consult a wide range of American, European and British research from 1950 to the present to reassure readers that ophthalmic chloramphenicol is a demonstrably effective, safe, cost-effective treatment for most superficial eye infections. They advise colleagues to consider any changes in the provision of antibiotic treatment for ophthalmic conditions carefully, as significant changes in practice may incur cost penalties on departmental or practice drug budgets, and may increase the likelihood of treatment failure which could result in patients having to pay second prescription charges. The requirement for nursing practice to be fully accountable, particularly when nurses are supplying drugs using Trust protocols, is emphasized. The article makes explicit the need for nursing practice to be well considered and based on current, credible research, and offers guidelines for nursing practice when ophthalmic chloramphenicol is supplied under protocol.

Random amplification of polymorphic DNA and microsatellite genotyping of pre- and posttreatment isolates of Candida spp. from human immunodeficiency virus-infected patients on different fluconazole regimens

Twelve patients infected with the human immunodeficiency virus (HIV) and with CD4 cell counts below 100 cells/microliter received fluconazole daily (200 mg; five patients) or weekly (400 mg; seven patients) for fungal prophylaxis during a 6-month period. Oropharyngeal swabs were taken at regular intervals in order to detect colonization with Candida spp. All yeast isolates were examined with respect to the development over time of fluconazole resistance. Genetic diversity among the strains was assessed in order to discriminate between selection of a resistant subclone and patient recolonization. Genotyping was performed through random amplification of polymorphic DNA (RAPD) analysis. Specific site polymorphisms were assayed by tracking length variability in several microsatellite loci. Finally, to maximize resolution, one of these loci (ERK1) was analyzed by nucleotide sequencing. Although the number of strains analyzed was too small to allow statistical verification, it appeared that when fluconazole was given weekly, a smaller fraction of the strains showed diminished sensitivity than when it was given daily. Genetic analyses allowed three different scenarios to be discerned. Resistance development in an otherwise apparently unchanged strain was seen for 1 of the 12 patients. Clear strain replacement was observed for 3 of the remaining 11 patients. For all other patients minor differences were seen in either the RAPD genotype or the microsatellite allele composition during the course of treatment. In general, microsatellite sequence data is in agreement with data obtained by other methods, but occasionally within-patient heterogeneity is indicated. The present results show that during fluconazole treatment colonizing strains can remain identical, be replaced by clearly different strains, or undergo small changes. Within a patient there may be different levels of intrastrain variation.

Assessment of haemostasis

Major surgery and some therapies carry with them the chance of severe bleeding. Recognising who is at risk and knowing what to do if it happens are important parts of the nurse's job. Debbie Field explains.

Comparison of treatments of persistent conduct problems in primary school children: a preliminary evaluation of a modified cognitive-behavioural approach

OBJECTIVE

Treatment for persistent conduct problems in primary school children was developed using a modification of cognitive-behavioural therapy (MCBT). Its effectiveness was evaluated by comparing it with conjoint family therapy (FT) and eclectic therapy (ET).

METHOD

Children with persistent conduct problems were randomly assigned to one of three treatment groups. They were assessed prior to treatment and then 6 months after. Measures included symptoms of the child; parents' mental health; stress of parenting; family functioning; and parental relationship. In addition, parents' and children's perception of the therapy were assessed and a treatment record was developed to track the treatment process.

RESULTS

Thirty-two children were recruited for the study. No statistically significant differences were found in terms of effectiveness between the three groups. In terms of parents' perception of the therapy, there was no difference on the perception of the qualities of the therapists, but on the perception of therapy MCBT was considered to be higher in cognitive-behavioural orientation.

CONCLUSION

Further research using a larger sample is required to evaluate MCBT. The study supports the idea that controlled treatment studies can be carried out within busy mental health services.

Special not different: general practitioners' accounts of their care of dying people

In modern Britain the majority of terminal care occurs in people's own homes and many dying people and their carers would prefer the death itself to occur in the home. The quality of terminal care in the home and the possibility of a home death depend to a great extent upon the care provided by GPs and community nurses. This paper reports on GPs' experiences of caring for dying people and their attitudes towards such work. It is based on unstructured interviews with 25 GPs who graduated from the 1979 entry cohort to the University of Leicester medical school. The respondents were recruited via a questionnaire following up previous research with this cohort on 'fear of death'. Although self-selecting, interviewees were not significantly different from those who did not volunteer for interview in any of the statistical analyses of the questionnaire data. There were a number of similarities in their accounts of their care of dying people. Common themes were that the care of dying people was important, rewarding and satisfying; that the GPs saw themselves as part of a team of carers, frequently as team co-ordinators; good working relationships with district nurses but less satisfactory relationships with hospitals and social workers; that patient and family were both recipients of care; and honesty in communication with dying people, albeit tempered. Three issues of contemporary relevance were: tensions over the role of hospice and specialist terminal care services; care of people with chronic terminal illnesses other than cancer; and the role of GPs in the social construction of bereavement.

An evaluation of palliative care services for cancer patients in the Southern Health and Social Services Board of Northern Ireland

An interview study of 55 lay carers of people who died from cancer in the Southern Board of Northern Ireland was undertaken using a combination of closed-format and open-ended questions. The aim of the study was to evaluate palliative care services delivered in the last six months of their lives to cancer patients who died either at home or in hospital. Two-thirds of the deaths (36) occurred in the domestic home, 45 of the deceased were admitted as hospital inpatients, and the great majority were in receipt of community nursing (53) and general practitioner (54) services. Open-ended questions were used to allow respondents to give their views about services in some detail and their views about good and bad aspects of services were sought. While they were generally satisfied with services specific areas of difficulty were identified in each aspect of care addressed by the study. The most favourable assessments were made of community nursing with the greatest number of negative comments being made about inpatient hospital care. Differing interests between some of those who were dying and their lay carers were found in two areas: the receipt of help from nonfamily members and the information that the deceased received about their terminal status.

Abundant microsatellite polymorphism in Saccharomyces cerevisiae, and the different distributions of microsatellites in eight prokaryotes and S. cerevisiae, result from strong mutation pressures and a variety of selective forces

We examined the distributions of short tandemly repeated DNAs (microsatellites) in nine complete microbial genomes (Saccharomyces cerevisiae, Archaeoglobus fulgidus, Escherichia coli, Haemophilus influenzae, Helicobacter pylori, Methanococcus jannaschii, Mycoplasma pneumoniae, M. genitalium, and Synechocystis PCC6803.) These repeats contribute differently to the global features of these genomes, and we explore the evolutionary implications of these differences by empirical examination of length polymorphisms at 20 long triplet-repeats repeats in S. cerevisiae, and by comparison of observed and expected repeat distributions. All of a sample of 20 microsatellites found in S. cerevisiae are highly polymorphic in length, suggesting that mutation pressure overcomes overall selection for small genome size that will tend to shorten or eliminate unnecessary DNA. By comparison, prokaryotes have fewer long repeats than expected, except for a few statistically improbable repeats that appear to function in gene regulation. Finally, we find that in all these genomes there is an excess of repeats shorter than those traditionally considered to be microsatellites. This finding suggests that even in prokaryotes these repeats are being generated by mutational pressures. These results have important potential implications for understanding genome stability and evolution in these microbial species.

Sequence analysis of a compound coding-region microsatellite in Candida albicans resolves homoplasies and provides a high-resolution tool for genotyping

Sequence diversity at a coding-region microsatellite locus of two diploid Candida species was surveyed. Twenty-one alleles from fourteen strains of Candida albicans and three alleles from two strains of the closely related Candida dubliniensis were sequenced. Results show independent length variation in two contiguous hexanucleotide repeats, one non-contiguous hexanucleotide repeat, and two non-contiguous trinucleotide repeats within a 120 bp coding region. A neighboring, non-repetitive 120 bp region showed no variation. The information density of sequence polymorphisms in this region provides a powerful tool for genotyping microorganisms in epidemiological studies, yielding detailed resolution of closely related strains, and clearly distinguishing the two species studied here. The individual length-variable repeat regions are very short (2-8 repeats), demonstrating that even very short microsatellites can show high levels of length variability when surrounded by similarly repetitive DNA. Extensive homoplasy was discovered among the C. albicans alleles, with the majority of overall length categories consisting of alleles with more than one sequence. Our results show that microsatellite length alone should not be used to assume either sequence identity or identity by descent. Microsatellite length mutations appear to have generated the high degree of both inter- and intraspecific polymorphism seen at the ERK1 locus, and form an island of variability in an otherwise well-conserved gene.

"Looking back, what period of your life brought you the most satisfaction"

Common myths hold that old persons are fixated on childhood memories, that they believe that youth is the best part of life, and that old age contains few satisfactions. Berkeley Older Generation Study members, when asked on two occasions during old age (M ages = 69.8 and 82.7) to name the periods of their lives that brought them the most and the least satisfaction, dispelled these myths. The thirties and forties were popular choices for periods of great satisfaction, but childhood and adolescence were quite unpopular for these old persons. "Right now" was named more often than any other life period as most satisfactory. Men and women did not differ in life periods nominated, but they did differ in the reasons given for their choices. Each period provided its own pattern of satisfactions and disappointments, and strong individual differences were apparent.