Biomedical subjects

L Ratcliffe

Publications and source records attributed to L Ratcliffe.

7 recordsLinked to original sources

PubMed2006

Clinical and diagnostic findings of an echovirus meningitis outbreak in the north west of England.

INTRODUCTION: An outbreak of echovirus meningitis occurred in the north west of England in 2001. This paper reviewed the clinical features and the role of different diagnostic methods. METHODS: This was a prospective study of adults admitted to a regional infectious disease unit with a probable diagnosis of meningitis, March to August 2001. RESULTS: Half the 40 cases were male; median age was 28 (range 16-51) years. Fifteen of 38 (39.5%) were smokers, and 20 of 24 (83.3%) had close contact with children. Median (range) duration of symptoms was 1.1 (0.25-7) days. Symptoms included headache (100%), photophobia (87.5%), and nausea (67.5%), and severity ranged from minimal signs to those consistent with a meningoencephalitis. The diagnosis was confirmed virologically in 29 of 40 (72%); echovirus 30 was isolated from six. Cerebrospinal fluid (CSF) enterovirus polymerase chain reaction (PCR) was positive in 26 of 32 (81%), and CSF virus culture in 3 of 16 (19%). Thirty one per cent of CSF samples had a neutrophil predominance, and 3 of 29 (10%) virologically confirmed cases had normal CSF microscopy and biochemistry. CONCLUSION: CSF microscopy may be normal or suggest bacterial meningitis in a substantial minority of cases of echovirus meningitis. CSF PCR for enterovirus seems to be more sensitive than virus culture of CSF, although PCR does not yield information on circulating virus type. Early and accurate diagnosis could reduce both use of parenteral antibiotics and length of hospital stay with both morbidity and cost implications. Close contact with children may be a risk factor, particularly if good hygiene measures are not practised.

Adolescent↗

PubMed2000

Disruptive sexual selection for plumage coloration in a passerine bird.

The theory of sexual selection was developed to explain the evolution of highly exaggerated sexual ornaments. Now supported by vast empirical evidence, sexual selection is generally considered to favour individuals with the most extreme trait expression. Here we describe disruptive selection on a sexual ornament, plumage coloration, in yearling male lazuli buntings (Passerina amoena). In habitats with limited good-quality nesting cover, the dullest and the brightest yearlings were more successful in obtaining high-quality territories, pairing with females and siring offspring, than yearlings with intermediate plumage. This pattern reflects the way that territorial adult males vary levels of aggression to influence the structure of their social neighbourhood. Adult males showed less aggression towards dull yearlings than intermediate and bright ones, permitting the dull yearlings to settle on good territories nearby. Fitness comparisons based on paternity analyses showed that both the adults and dull yearlings benefited genetically from this arrangement, revealing a rare example of sexually selected male-male cooperation.

Animals↗

PubMed1998

Syphilis in pregnant women and their children in the United Kingdom: results from national clinician reporting surveys 1994-7.

OBJECTIVE: To measure the incidence of syphilis detected in pregnancy and congenital syphilis in the United Kingdom. DESIGN: Surveys through consultants in genitourinary medicine and paediatricians with active surveillance. SETTING: United Kingdom, 1994-7. SUBJECTS: Women treated for syphilis in pregnancy, and children with early congenital syphilis born in the United Kingdom. RESULTS: Over 3 years 139 women were diagnosed with and treated for syphilis in pregnancy; 121 were detected through antenatal screening. Thirty one had confirmed or probable congenitally transmissible syphilis, putting their pregnancies at risk. These were minimum figures but are compatible with the 90 to 100 women newly diagnosed annually as having infectious or early latent syphilis. A universal screening policy would require 18 600 and 55 700 women (maximum numbers) to be screened, respectively, to detect one woman needing treatment and to prevent one case of congenital syphilis. Nine presumptive cases of children with congenital syphilis born in the United Kingdom were reported. Mothers requiring treatment for syphilis were found in almost every health region but were more prevalent in London and the south east. Being born abroad and belonging to an ethnic minority group were strong risk factors, but 14% (19 of 121) of cases treated and six of 31 definite or probably transmissible cases occurred in white women born in the United Kingdom. CONCLUSIONS: Congenitally transmissible syphilis continues to occur among pregnant women in the United Kingdom. Cases would be missed and stillbirths and congenitally infected babies would occur if antenatal screening was abandoned.

Emigration and Immigration↗

PubMed1998

Reference laboratory surveillance of syphilis in England and Wales, 1994 to 1996.

Routine surveillance of syphilis of public health importance (infectious, congenital, and neurosyphilis) began in England and Wales in 1994, using reports from six PHLS laboratories that undertook serological and other reference work. One hundred and thirty-one cases were reported in the first two years, including 100 cases of infectious syphilis, with all regions reporting some infectious syphilis. Reports from PHLS laboratories represented one sixth of the number of cases seen in genitourinary clinics (KC60 data), but both systems produced comparable results. Laboratory reports provided more data on risk factors, which were not available elsewhere. This study documents the risk in England and Wales from infections originating in eastern Europe, where sexually transmitted infections including syphilis have reached epidemic proportions. Forty-five per cent of cases of infectious syphilis were reported to have been acquired in the United Kingdom (UK) and 59% of people with infectious syphilis were reported to have been born in the UK. Twenty per cent of the infectious cases were associated directly or indirectly with transmission in Russia or elsewhere in eastern Europe. The majority of infectious cases were from the white ethnic group. Eighty-five per cent of cases of infectious syphilis were reported to have been acquired heterosexually; 26% of male cases were reported to have been acquired homosexually. The PHLS laboratory reporting system is now well established, and could usefully be expanded to include other, non PHLS, laboratories that undertake reference work. It has the capacity to detect changes in the national epidemiology of syphilis, including imported infections.

Adult↗

PubMed1997

Song transmission and auditory perception of distance in wood warblers (Parulinae)

The influence of breeding habitat on the evolution of song structure was examined in four wood warbler species of the sub-family Parulinae. The effects of song degradation on the ability of territorial paruline males to estimate distance by means of acoustic cues was also investigated. Song transmission characteristics of paruline breeding habitats were compared in southeastern Ontario, Canada; songs native to the habitat in which they were broadcast did not degrade less than foreign songs. The response of territorial paruline males to playback of 'near' (undegraded) and 'far' (degraded) conspecific songs broadcast from the same position within the territory at the same amplitude were then compared. Males responded to near songs as they would to a conspecific territorial intruder and with less intensity to far songs, suggesting that males may use cues from song degradation to estimate distance to vocal conspecifics. Our results from transmission and playback experiments are discussed with respect to the ranging hypothesis, which proposes that selection should favour males that structure songs to minimize their degradation, so that songs function to disrupt or intimidate rivals by providing unreliable distance cues.

Journal Article↗

PubMed1993

Sibling visitation: how far should the pendulum swing?

This study describes development of early interaction between siblings. Subjects (N = 22) were the older siblings (30 to 52 months) of healthy new babies. Data were collected to describe initial contact, regressive behaviors, and extent and quality of sibling interaction at 3 weeks, 5 months, and 7 months. Patterns of visualization, touch, and communication were observed. There was no evidence of sibling regressive behavior. Behaviors were more positive than negative and older siblings were in proximity for initiation of interaction by the new baby at 5 and 7 months. Findings indicate positive sibling relationships may be the norm rather than the exception.

Age Factors↗

PubMed1986

Song sequence discrimination in the black-capped chickadee (Parus atricapillus).

Captive black-capped chickadees (Parus atricapillus) were presented with normal and altered versions of their species-specific "fee bee" song, to determine how note type, number, and sequence affect recognition. The number of perch changes and vocalizations (analyzed separately) given in response to playback did not differ reliably as a function of song type, whereas latency to first vocalization after playback did. In an initial experiment using two-note songs, birds vocalized sooner to songs beginning with fee than with bee and to fee bee than to fee fee. In a second experiment, birds were presented with shortened (single note), normal, and lengthened (three note) songs each consisting of a single-note type (either fee or bee). Habituation slowed responding to altered songs but not to fee bee over three test sessions. Results from the first session suggest that chickadees distinguished single fees and three-note songs from normal song, single fees from single bees, and two-note songs from three-note songs. Results from the third session suggested that chickadees distinguished normal song from any of the altered songs. The internal representation of conspecific song in the chickadee thus distinguishes between fee and bee notes, contains information about note order, and is sensitive to note number. The pattern of responses is consistent with a model of recognition based on note-by-note integration of individual decisions about song structure.

Animals↗