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J Wolstenholme

Publications and source records attributed to J Wolstenholme.

At least 19 recordsLinked to original sources
PubMed2006

Association of Clinical Cytogeneticists chorion villus sampling database 1987-2000.

OBJECTIVES: To produce a fully searchable Microsoft Access database of mosaic and non-mosaic cytogenetic abnormalities, detected during diagnostic chorionic villi sampling (CVS) to aid laboratories in predicting pregnancy outcome, in particular differentiating between cases of likely genuine fetal cytogenetic abnormalities and those likely to represent confined placental mosaicism (CPM). METHODS: Retrospective collection of referral data, initial karyotype data, follow-up karyotype data and pregnancy outcome data from almost all cytogenetically abnormal diagnostic CVS, processed in UK National Health Service laboratories, between 1987 and 2000. Collection of similar data from a published series of CVS and individual case reports. RESULTS: A fully searchable database of abnormal CVS cases, containing over 5000 entries, has been produced. This is available to download at http://www.ncl.ac.uk/cvs/. CONCLUSIONS: Following detection of a cytogenetic abnormality during prenatal diagnosis using CVS, use of this database allows rapid access to comparable cases from the United Kingdom and the literature. This database will improve the speed of availability and quality of information available to clinicians and patients for pregnancy management and counselling purposes. The database has been designed with future data collection in mind, and can be developed for wider research use, through more detailed registries of individual chromosome abnormalities.

Chorionic Villi Sampling↗
PubMed2002

Estimating the relationship between disease progression and cost of care in dementia.

BACKGROUND: Previous studies have shown a positive relationship between disease severity and cost. AIMS: To explore the factors affecting time to institutionalisation and estimate the relationship between the costs of care and disease progression. METHOD: Retrospective analysis of a longitudinal data-set for a cohort of 100 patients diagnosed with Alzheimer's disease or vascular dementia. RESULTS: Changes in both Mini-Mental State Examination (MMSE) and Barthel scores have independent and significant marginal effects on costs. Each one-point decline in the MMSE score is associated with a pound sterling 56 increase in the four-monthly costs, whereas each one-point fall in the Barthel index is associated with a pound sterling 586 increase in costs. CONCLUSIONS: It may be inappropriate for economic models of disease progression in dementia to be based solely on measures of cognitive change. MMSE and the Barthel index are independent significant predictors of time to institutionalisation and cost of care, but changes in the Barthel index are particularly important in predicting costs outside institutional care.

Age Factors↗
PubMed2001

Maternal uniparental heterodisomy for chromosome 2: detection through 'atypical' maternal AFP/hCG levels, with an update on a previous case.

We report a case of maternal uniparental disomy 2, detected through routine screening of placental karyotypes following the finding of 'atypical' AFP/hCG levels in the second trimester, with intrauterine growth retardation (IUGR) but otherwise normal outcome at term. Although the child remained small, subsequent early physical and mental development has also been normal. Additionally, we report long-term follow-up of an earlier case, again with relatively normal physical and mental development. The significance of atypical AFP/hCG results and the predictive value of prenatal testing for UPD2 in trisomy 2 confined placental mosaicism (CPM) cases are discussed.

Adult↗
PubMed2001

Mass population screening for colorectal cancer: factors influencing subjects' choice of screening test.

OBJECTIVES: To identify socio-demographic, economic, medical and attitudinal factors that explain subjects' choice of test for screening for colorectal cancer (biennial faecal occult blood test versus once-only flexible sigmoidoscopy). METHODS: Data obtained from a questionnaire, administered by general practitioners and returned by approximately 2700 asymptomatic subjects. Thereafter, logistic regression modelling to explain willingness to participate in screening, whether or not a test preference is expressed, and the nature of the preference. RESULTS: An interest in undertaking screening is more probable if the subject is white, older, married and possesses a high health motivation. An intention to participate is more probable if the subjects are particularly worried about the disease, feel themselves to be particularly susceptible to it, and have already had experience of screening for colorectal and (if female) other cancers. Persons in receipt of a household income below 10,000 Pounds are less likely to express an interest in screening. Women are more likely to express a test preference and this preference is more likely to be for the faecal occult blood test. Subjects' worries and perception of risk are associated with reported experiences of cancer, stomach problems and depression. A positive attitude towards screening is positively associated with frequency of dental visits. CONCLUSIONS: Socio-demographic, economic and other factors evidently influence subjects' preferences for particular screening tests and, by implication, the likelihood of compliance with any future screening offer. The models support the view that participation in colorectal cancer screening has as much to do with a positive attitude towards health and health promotion generally as with any specific concern about the disease.

Adult↗
PubMed2000

Maternal age and trisomy--a unifying mechanism of formation.

The mechanism of trisomy formation and its relationship to increased maternal age is not understood. Molecular analysis of the pattern of inheritance of DNA markers in trisomy families shows trisomies can be grouped according to whether the affected chromosomes inherited from their mothers are heterozygous or homozygous with respect to the centromeres. Furthermore, molecular analysis reveals that those that are heterozygous have fewer chiasmata, which are located more distally, while those that are homozygous have more chiasmata proximally located. Cytogenetic analysis of human oocytes shows that the kind of imbalance predicted by the classic hypothesis of nondisjunction, i.e. extra whole chromosomes at the second metaphase, is rarely found, whereas the common expression of imbalance is seen as single chromatids. We hypothesise that one mechanism links these data: the mechanism depends on the prediction from the cytogenetic data that cohesion within the bivalent complex is severely weakened during the extended dictyate stage in older women. Consequently, when meiosis resumes, at the time of ovulation, the bivalent emerges as four chromatids held together only by its chiasmata. In accordance with the rules of orientation on the spindle, the final balanced shape of the configuration achieved at metaphase I, in this case determined by the position of the chiasmata, will dictate whether the subsequent segregation of the chromatids will result in their heterozygosity or homozygosity. It follows that the concept of "first division" and "second division" errors, i.e. of nondisjunction originating at first or second meiotic division as defined by centromeric hetero- or homozygosity, may be erroneous.

Centromere↗
PubMed2000

A review of alternative approaches to healthcare resource allocation.

The resources available for healthcare are limited compared with demand, if not need, and all healthcare systems, regardless of their financing and organisation, employ mechanisms to ration or prioritise finite healthcare resources. This paper reviews alternative approaches that can be used to allocate healthcare resources. It discusses the problems encountered when allocating healthcare resources according to free market principles. It then proceeds to discuss the advantages and disadvantages of alternative resource allocation approaches that can be applied to public health systems. These include: (i) approaches based on the concept of meeting the needs of the population to maximising its capacity to benefit from interventions; (ii) economic approaches that identify the most efficient allocation of resources with the view of maximising health benefits or other measures of social welfare; (iii) approaches that seek to ration healthcare by age; and (iv) approaches that resolve resource allocation disputes through debate and bargaining. At present, there appears to be no consensus about the relative importance of the potentially conflicting principles that can be used to guide resource allocation decisions. It is concluded that whatever shape tomorrow's health service takes, the requirement to make equitable and efficient use of finite healthcare resources will remain.

Health Care Rationing↗
PubMed1999

Costs of breast cancer treatment in the United Kingdom.

Breast cancer is a major source of mortality and morbidity to women in the UK. In this paper we estimate the costs of treating breast cancer using random samples of secondary and primary care records. We estimate the average cost per case of breast cancer to be pound 7247 which gives a total cost of pound 243 million per annum for the whole of the UK.

Journal Article↗
PubMed1999

The predictive value of findings of the common aneuploidies, trisomies 13, 18 and 21, and numerical sex chromosome abnormalities at CVS: experience from the ACC U.K. Collaborative Study. Association of Clinical Cytogeneticists Prenatal Diagnosis Working Party.

We report 611 non-mosaic and 91 mosaic findings of trisomies 13, 18 and 21, and numerical sex chromosome abnormalities in a series of 20,527 CVS, in the Association of Clinical Cytogeneticists U.K. Collaborative Study, the majority with analysis of both direct preparations and cultured cells. No false-positive results were encountered among the 611 non-mosaic cases, making these findings a very reliable indicator of the fetal karyotype. One false-negative case was reported. In contrast, the 91 mosaic abnormalities were unreliable predictors of fetal abnormality. Many were associated with normal outcomes, but a significant proportion of cases of each individual aneuploidy proved genuine. Mosaicism for 45,X, and trisomies 13 and 18 was disproportionately common. 17 of the mosaic cases showed complete discordance between the karyotype from direct preparations and that from cultured cells. All would have resulted in either a false-positive or a false-negative finding if only one technique had been used. Based on our experience, and that of others, we believe that the highest level of predictive accuracy using CVS can only be achieved if both direct preparation and cell culture are performed. In addition, we continue to recommend that all pregnancies demonstrating mosaicism for these aneuploidies at CVS undergo amniocentesis or fetal blood sampling to differentiate between confined placental mosaicism and true fetal karyotypic abnormality.

Aneuploidy↗
PubMed1998

Home-based versus hospital-based care for serious mental illness. Controlled cost-effectiveness study over four years.

BACKGROUND: The Daily Living Programme (DLP) offered intensive home-based care with problem-centred case management for seriously mentally ill people facing crisis admission to the Maudsley Hospital, London. The cost-effectiveness of the DLP was examined over four years. METHOD: A randomised controlled study examined cost-effectiveness of DLP versus standard in/out-patient hospital care over 20 months, followed by a randomised controlled withdrawal of half the DLP patients into standard care. Three patient groups were compared over 45 months: DLP throughout the period, DLP for 20 months followed by standard care, and standard care throughout. Bivariate and multivariate analyses were conducted (the latter to standardise for possible inter-sample differences stemming from sample attrition and to explore sources of within-sample variation). RESULTS: The DLP was more cost-effective than control care over months 1-20, and also over the full 45-month period, but the difference between groups may have disappeared by the end of month 45. CONCLUSIONS: The reduction of the cost-effectiveness advantage for home-based care was perhaps partly due to the attenuation of DLP care, although sample attrition left some comparisons under-powered.

Adolescent↗
PubMed1998

Prenatal diagnosis of mosaic trisomy 8 with investigations of the extent and origin of trisomic cells.

A case of trisomy 8 mosaicism, which presented at obstetric ultrasound at 18 weeks' gestation with a distended bladder and absence of amniotic fluid, is described. Analysis of DNA microsatellite polymorphisms indicates that the trisomic cell line most likely arose as the result of a post-fertilization non-dysjunction event in early development of a chromosomally normal pre-implantation embryo. The distribution of normal and trisomy 8 cells suggests that in this pregnancy there has been either uneven allocation of abnormal cells to the extra-embryonic mesoderm, or selection against the proliferation of trisomic cells in trophoblast derived cell lineages. This prenatal detection of trisomy would not have been possible if only analysis of direct preparations had been undertaken.

Adult↗
PubMed1997

Severe fetal malformations associated with trisomy 16 confined to the placenta.

Chorionic villus sampling (CVS) and amniocentesis were performed on a pregnant woman during her 24th week of amenorrhoea following an ultrasound scan which showed a fetus with hydrocephaly, intrauterine growth retardation (IUGR), and a single umbilical artery. The direct karyotype from the cytotrophoblast was non-mosaic 47,XXX,+16, while in amniotic fluid and several fetal tissues, studied post-mortem, a normal 46,XX karyotype was found in more than 400 cells. Uniparental disomy (UPD) was excluded by molecular genetic studies. Autopsy confirmed the echographic findings; in addition, agenesis of the corpus callosum and polysplenia were observed. This is the second example of congenital abnormality associated with confined placental mosaicism (CPM) for trisomy 16, without evidence of either UPD or an apparent contribution of abnormal cells to the fetus.

Adult↗
PubMed1997

Detection of mosaic and non-mosaic chromosome abnormalities in 6- to 8-day old human blastocysts.

A reliable technique has been developed for the production of good quality G-banded chromosome preparations from 6- to 8-day-old human blastocysts (20-800 cell stage) from an in vitro fertilization programme. The technique involves a thymidine cell division synchronization step to reduce the exposure time to colcemid, in conjunction with a simple 70% acetic acid disaggregation procedure to produce discrete metaphases for analysis. Of 105 blastocysts processed by this technique, 9 were lost during handling and 10 showed no dividing cells. The remaining 86 produced useful separate metaphases with a mean mitotic activity of 6.5%. A full G-banded karyotype was obtained from 1-6 cells in 55 blastocysts (64%), incomplete G-banded analysis but with full information of ploidy was obtained from 18 blastocysts (21%), with 13 (15%) producing no useful cytogenetic results. Abnormalities observed included polyploidy, diploid/polyploid mosaicism, non-mosaic trisomy 16 (2 cases), 46,Xdel(X)-(q21)/46,XX (1 case) and several single cells with trisomies or structural anomalies in otherwise normal blastocysts. Variable levels of structural chromosome damage, with apparent interchanges, chromosome branching and anomalous chromatid pairing were also seen.

Aneuploidy↗
PubMed1997

Is there an increased prevalence of severe learning disabilities among British Asians?

Age-specific prevalence rates for learning disabilities among the Asian communities in three Metropolitan Boroughs in the North of England are presented. These data indicate that: (1) below school age there is little difference in the apparent prevalence of severe learning disabilities between the Asian and non-Asian communities; (2) between 5 and 34 years of age, however, the apparent prevalence of severe learning disabilities is approximately three times higher among the Asian community when compared with the non-Asian community.

Adolescent↗
PubMed1997

Paediatric echocardiography by telemedicine--nine years' experience.

In 1987 we established a realtime echocardiography service by telemedicine from the paediatric cardiology department of a tertiary-care hospital in Halifax. The service was initially provided to single regional hospital but was expanded to six regional hospitals in the three Canadian Maritime Provinces. The system used a dial-up broadband video-transmission service provided by the telephone companies. Records of all transmissions were kept prospectively and reviewed to January 1997. A total of 324 transmissions were made. During 1995-96 there were 135 studies: 69 (51%) were urgent examinations of newborn children and 30 (22%) were urgent examinations of older children; repeat studies and postoperative checks (usually for pericardial effusion) accounted for the other 36 studies (27%). The images were of broadcast quality except in five cases where problems with transmission or poor sedation occurred. A comparison of 26 transmitted studies with repeat, 'in person' studies showed no important discrepancies in diagnosis. During the two-year study period, the cost of the network (equipment leasing costs and telecommunications costs) was C$90,000. Use of the telemedicine network saved unnecessary patient transfer in 31 cases. The cost of the transportation avoided was C$100,000-C$118,000. This review confirms our preliminary findings that broadband echocardiography transmission provides a service comparable in availability and accuracy to that provided in our paediatric cardiology division.

Canada↗
PubMed1997

Promiscuous translocations of chromosome arm 17q in human neuroblastomas.

Deletions of chromosome arm 1p and amplification of the MYCN oncogene are well-recognized genetic changes in neuroblastoma cells. Technical difficulties in cytogenetic analysis of this tumour have hampered the recognition of other recurring abnormalities, but recent use of molecular cytogenetic techniques has indicated significant involvement of chromosome arm 17q. In primary tumours and in cell lines, a recurrent unbalanced translocation t(1p;17q) has been identified by fluorescence in situ hybridization. We confirm the occurrence of this translocation in primary tumours and, in addition, we describe seven new structural rearrangements all of which result in gain of 17q in tumour cells. These rearrangements involved chromosome arms 9p, 10q, 11p, 14q, and 16q. Triplication of the 17q arm was seen in one case. The 17q breakpoint was most commonly q21. All these 17q changes were found in near-diploid tumours. We have also reviewed the literature for neuroblastoma karyotypes involving 17q abnormalities; taken in conjunction with our findings this indicates a remarkable promiscuity of translocation partners, with more than 20 different chromosome regions involved in 17q translocations.

Bone Marrow Neoplasms↗
PubMed1996

Confined placental mosaicism for trisomies 2, 3, 7, 8, 9, 16, and 22: their incidence, likely origins, and mechanisms for cell lineage compartmentalization.

Analysis of confined placental mosaicism (CPM) for trisomies 2, 3, 7, 8, 9, 16, and 22, in diagnostic chorionic villus sampling procedures, demonstrates apparent incidences of CPM for individual trisomies of between 9 and 91 cases per 100,000 pregnancies, with trisomy 7 being the most common. More detailed analysis of the percentage of aneuploid cells present, and the distribution of abnormality between the cytotrophoblast and extra-embryonic mesoderm cell lineages, shows a highly specific pattern for each chromosome. Theoretical considerations, in conjunction with direct observations, indicate that the overriding influence on the patterns of cell distribution seen in CPM is the distribution of aneuploid cells laid down during blastogenesis. This in turn reflects closely the origin of mosaicism from either correction of a trisomic conception or post-fertilization somatic error. The pattern of aneuploid cells for each trisomy, as seen at the end of the first trimester and later in pregnancy, can therefore be used to predict the relative contribution of meiotic and mitotic errors to CPM, and hence the likely incidences of uniparental disomy from this source, upd(16)mat being the most common (1 in 10,000 continuing pregnancies). In addition, CPM for trisomies 2, 3, and 8 shows strong evidence of a non-random distribution of aneuploid cells between the different extra-embryonic cell lineages. Analysis of comparable data from spontaneous abortion material repeats this non-random pattern for trisomies 2 and 3, and suggests that a similar phenomenon may also be occurring for trisomy 22. A non-random distribution could be attributable to selection for or against, or intolerance of, particular trisomic cells in certain lineages, but is more probably a result of either cell lineage-specific non-disjunction or consistent uneven compartmentalization of aneuploid cells during blastocyst development.

Chorionic Villi Sampling↗