PubMed Health⌕ Search

Biomedical subjects

L Parsons

Publications and source records attributed to L Parsons.

At least 19 recordsLinked to original sources
PubMed2002

Analysis of tuberculosis surveillance in Hungary in 2000.

SETTING: Hungary, Central Europe, with a population of 10.3 million living in 20 administrative districts (19 counties and the capital). OBJECTIVE: To summarize the results of the first year of the revised National Tuberculosis Surveillance System. DESIGN: Retrospective survey of the National Tuberculosis Surveillance Center (NTSC) database. METHODS: Analysis of data on all tuberculosis cases reported to the NTSC in 2000. Drug susceptibility results were evaluated in line with WHO and IUATLD definitions. RESULTS: During 2000, a total of 3598 patients with tuberculosis were reported. Only 40% of these were bacteriologically confirmed. Although susceptibility testing has been required for previously untreated culture-positive cases, only 801 (67.8% of the bacteriologically confirmed cases) were tested in 2000. Drug resistance was detected in 10.7% of previously untreated and in 23.5% of previously treated patients. Multidrug-resistant (MDR) cases were not common: only 1.5% of the isolates from previously untreated patients and 4.9% of those from previously treated patients were MDR. CONCLUSIONS: The results suggest that the NTSC should work towards increasing the numbers of cases that are bacteriologically confirmed. In addition, some form of surveillance system should be instituted to ensure that mandatory susceptibility testing is performed on all isolates from previously untreated tuberculosis patients.

Adolescent↗
PubMed2001

Application of the TIMI risk score for ST-elevation MI in the National Registry of Myocardial Infarction 3.

CONTEXT: The Thrombolysis in Myocardial Infarction (TIMI) risk score for ST-elevation myocardial infarction (STEMI) is a simple integer score for bedside risk assessment of patients with STEMI. Developed and validated in multiple clinical trials of fibrinolysis, the risk score has not been validated in a community-based population. OBJECTIVE: To validate the TIMI risk score in a population of STEMI patients reflective of contemporary practice. DESIGN, SETTING, AND PARTICIPANTS: The risk score was evaluated among 84 029 patients with STEMI from the National Registry of Myocardial Infarction 3 (NRMI 3), which collected data on consecutive patients with myocardial infarction (MI) from 1529 US hospitals between April 1998 and June 2000. MAIN OUTCOME MEASURES: Ability of the TIMI risk score to correctly predict risk of death in terms of model discrimination (c statistic) and calibration (agreement of predicted and observed death rates). RESULTS: Patients in NRMI 3 tended to be older, to be more often female, and to have a history of coronary disease more often than those in the derivation set. Forty-eight percent received reperfusion therapy. The TIMI risk score revealed a significant graded increase in mortality with rising score (range, 1.1%-30.0%; P<.001 for trend). The risk score showed strong prognostic capacity overall (c = 0.74 vs 0.78 in derivation set) and among patients receiving acute reperfusion therapy (c = 0.79). Predictive behavior of the risk score was similar between fibrinolytic-treated patients (n = 23 960; c = 0.79) and primary percutaneous coronary intervention patients (n = 15 348; c = 0.80). In contrast, among patients not receiving reperfusion therapy, the risk score underestimated death rates and offered lower discriminatory capacity (c = 0.65). CONCLUSIONS: Sufficiently simple to be practical at the bedside and effective for risk assessment across a spectrum of patients, the TIMI risk score may be useful in triage and treatment of patients with STEMI who are treated with reperfusion therapy.

Aged↗
PubMed2001

Solution structure of HI0257, a bacterial ribosome binding protein.

A novel bacterial ribosome binding protein, protein Y (also known as YfiA), was recently shown to reside at the 30S/50S subunit interface and to stabilize the ribosomal 70S complex against dissociation at low magnesium ion concentrations. We report here the three-dimensional NMR structure in solution of a homologue from Haemophilus influenzae, HI0257, that has 64% sequence identity to protein Y. The 107 residue protein has a beta-alpha-beta-beta-beta-alpha folding topology with two parallel alpha-helices packed against the same side of a four-stranded beta-sheet. The closest structural relatives are proteins with the double-stranded RNA-binding domain (dsRBD) motif although there is little (<10%) sequence homology. The most immediate differences between the dsRBD and HI0257 structures are that (1) HI0257 has a larger beta-sheet motif with an extra beta-strand at the N-terminus, (2) the helices are parallel in HI0257 but at an angle of about 30 degrees to each other in the dsRBD, and (3) HI0257 lacks the extended loop commonly seen between the first and second beta-strands of the dsRBD. Further, an analysis of the surface electrostatic potential in HI0257 and the dsRBD family reveals significant differences in the location of contiguous positively (and negatively) charged regions. The structural data, in combination with sequence analysis of HI0257 and its homologues, suggest that the most likely mode of RNA recognition for HI0257 may be distinct from that of the dsRBD family of proteins.

Amino Acid Sequence↗
PubMed2001

A probabilistic atlas and reference system for the human brain: International Consortium for Brain Mapping (ICBM).

Motivated by the vast amount of information that is rapidly accumulating about the human brain in digital form, we embarked upon a program in 1992 to develop a four-dimensional probabilistic atlas and reference system for the human brain. Through an International Consortium for Brain Mapping (ICBM) a dataset is being collected that includes 7000 subjects between the ages of eighteen and ninety years and including 342 mono- and dizygotic twins. Data on each subject includes detailed demographic, clinical, behavioural and imaging information. DNA has been collected for genotyping from 5800 subjects. A component of the programme uses post-mortem tissue to determine the probabilistic distribution of microscopic cyto- and chemoarchitectural regions in the human brain. This, combined with macroscopic information about structure and function derived from subjects in vivo, provides the first large scale opportunity to gain meaningful insights into the concordance or discordance in micro- and macroscopic structure and function. The philosophy, strategy, algorithm development, data acquisition techniques and validation methods are described in this report along with database structures. Examples of results are described for the normal adult human brain as well as examples in patients with Alzheimer's disease and multiple sclerosis. The ability to quantify the variance of the human brain as a function of age in a large population of subjects for whom data is also available about their genetic composition and behaviour will allow for the first assessment of cerebral genotype-phenotype-behavioural correlations in humans to take place in a population this large. This approach and its application should provide new insights and opportunities for investigators interested in basic neuroscience, clinical diagnostics and the evaluation of neuropsychiatric disorders in patients.

Adult↗
PubMed2001

Segmental amplification of 11q23 region identified by fluorescence in situ hybridization in four patients with myeloid disorders: a review.

Four cases with a segmental amplification of 11q23 region were detected by FISH. The amplification was either contiguous amplification on chromosome 11, or multiple markers involving the 11q23 region. The markers were derivative chromosomes, or isochromosomes. Amplification of 11q23 region was associated with complex karyotypes at the time of diagnosis or following treatment in secondary leukemias. Three were AML cases belonging to either AML-M5a or AML-1 subtypes and one was a myeloproliferative disorder. These cases were resistant to treatment. Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) studies using MLL, 11 painting, or 11 centromere probes ascertained the segmental amplification. Since the patients did not respond to treatment the amplification of gene or genes that map to 11q23 may be responsible for the unfavorable prognosis. Hence, this type of amplifications could have clinical significance.

Acute Disease↗
PubMed2001

An hsr on chromosome 7 was shown to be an insertion of four copies of the 11q23 MLL gene region in an HIV-related lymphoma.

A 45-year-old male with AIDS presented with a cecal diffuse large B-cell lymphoma. Cytogenetic and flourescence in situ hybridization (FISH) studies revealed a complex karyotype with multiple aberrations that included a translocation, t(8;14) involving MYC on chromosome 14. This is specific to B-cell lymphomas. There were also frequently observed secondary changes such as chromosome 1 rearrangement leading to trisomy of 1q and loss of tp53 from the deleted chromosome 17. A unique secondary abnormality was an hsr on chromosome 7, which by FISH and SKY investigations was shown to originate from chromosome 11 involving 4 copies of the MLL gene region.

Cecal Neoplasms↗
PubMed2000

FISH analysis of an AML-M5a with segmental rearrangements involving 11q23-MLL region.

A 66-year-old man was diagnosed 10 years ago with thrombocytosis and treated with hydroxyurea. Recently, his condition deteriorated and he was found to have 68% blasts in the blood and AML-M5a. Conventional cytogenetic analysis and fluorescence in situ hybridization studies using 11-painting and MLL probes showed that chromosome 11 had duplications or triplications; the markers were also derived from the chromosome 11-MLL region. Therefore, we have demonstrated segmental rearrangement of chromosome 11 involving the MLL region resulting in multiple copies of the MLL gene.

Aged↗
PubMed2000

Ultrasonography for cervical length measurement: agreement between transvaginal and translabial techniques.

OBJECTIVE: To assess agreement between transvaginal and translabial ultrasonography for measuring cervical length in the second and third trimesters. METHODS: Eighty-four obstetric patients at 14-40 weeks' gestation were enrolled. Three images of the cervix were obtained by translabial (3.5-MHz curvilinear transducer) and transvaginal (6.5-MHz endovaginal probe) ultrasonography. The mean cervical length obtained by using each method was used for data analysis. The McNemar chi(2) test was used to assess the difference between techniques in their ability to obtain a measurement. The paired t-test was used to evaluate the differences between the measurements. The mean difference and SD for the differences were used to calculate the limits of agreement. An acceptable difference was defined as less than 0.5 cm. RESULTS: Cervical length measurements were obtained in 84 patients (100%) by using the transvaginal technique and in 80 patients (95%) by using the translabial technique (P =.1). Eighty patients had both transvaginal and translabial measurements for comparison. The mean difference in cervical length was 0.37 cm (P <.001; 95% confidence interval [CI] 0. 21, 0.52). The upper and lower limits of agreement were 1.75 cm (95% CI 1.48, 2.02) and -1.01 cm (95% CI -0.74, -1.28), respectively. The differences between the two measurements were within these limits 95% of the time. These limits of agreement were greater than the acceptable difference of 0.5 cm. CONCLUSION: Transvaginal and translabial techniques should not be used interchangeably for clinical assessment of cervical length because agreement between the methods is not within an acceptable range.

Adult↗
PubMed2000

Violence against women and reproductive health: toward defining a role for reproductive health care services.

Since a large proportion of U.S. women receive reproductive health care services each year, reproductive health care settings offer an important opportunity to reach women who may be at risk of or experiencing intimate partner violence (IPV). Although screening women for IPV in clinical health care settings has been endorsed by national professional associations and organizations, scientific evidence suggests that opportunities for screening in reproductive health care settings are often missed. This commentary outlines what is known about screening and intervention for IPV in clinical health care settings, and points out areas that need greater attention. The ultimate goal of these recommendations is to increase the involvement of reproductive health care services in sensitive, appropriate, and effective care for women who may be at risk of or affected by IPV.

Adolescent↗
PubMed2000

Do practice-based preventive child health services affect the use of hospitals? A cross-sectional study of hospital use by children in east London.

BACKGROUND: Acute paediatric admissions have risen steadily over the past 20 years. During the same period, practice-based child health clinics have increased, although provision is less common in areas of deprivation where hospital use is greatest. AIM: To investigate the contribution of practice-based, preventive child health services to rates of hospital utilisation in children under five years of age. METHOD: A cross-sectional retrospective study examining practice variations in paediatric acute admissions, outpatient referrals, and accident and emergency (A&E) department attendances in the East London and the City Health authority, including all 164 practices in the inner-city boroughs of Hackney, Newham, Tower Hamlets, and the City of London. The main outcome measures were practice-based paediatric hospital attendance rates, for discrete age and sex bands, for the year to 31 March 1996. RESULTS: Hospital use varied with age and sex, with the rates being highest for the youngest children and for boys. The median A&E attendance rate (including reattendances) for boys up to one year of age was 897 per thousand children per practice. In east London, 62% of practices are registered for child health surveillance and 71% provide a child health clinic. Practice approval for child health surveillance, and the provision of child health clinics, did not account for differences between practices in hospital use, but proportionally greater health visiting hours were significantly related to lower rates of emergency hospital admission by young children. Multivariate analyses revealed that up to 23% of the variation between practice admission rates could be explained by health visiting hours. CONCLUSIONS: We found significant associations between the amount of health visiting time available to the practice population and rates of acute admission and outpatient referral among children up to five years of age. These findings suggest that increasing health visitor provision could contribute to lower paediatric emergency admission and outpatient referral rates. A small change would have a significant effect, particularly among the youngest children, given that during the study year 10,000 children under two years of age in east London were either admitted or referred to hospital.

Age Factors↗
PubMed1999

In vitro transposition of Tn552: a tool for DNA sequencing and mutagenesis.

We have explored the potential of the Tn 552 in vitro transposition reaction as a genetic tool. The reaction is simple (requiring a single protein component), robust and efficient, readily producing insertions into several percent of target DNA. Most importantly, Tn 552 insertions in vitro appear to be essentially random. Extensive analyses indicate that the transposon exhibits no significant regional or sequence specificity for target DNA and leaves no discernible 'cold' spots devoid of insertions. The utility of the in vitro reaction for DNA sequencing was demonstrated with a cosmid containing the Mycobacterium smegmatis recBCD gene cluster. The nucleotide sequence of the entire operon was determined using 71 independent Tn 552 insertions, which generated over 13.5 kb of unique sequence and simultaneously provided a comprehensive collection of insertion mutants. The relatively short ends of Tn 552 make construction of novel transposons a simple process and we describe several useful derivatives. The data presented suggest that Tn 552 transposition is a valuable addition to the arsenal of tools available for molecular biology and genomics.

DNA Transposable Elements↗
PubMed1999

Sex-based differences in early mortality after myocardial infarction. National Registry of Myocardial Infarction 2 Participants.

BACKGROUND: There is conflicting information about whether short-term mortality after myocardial infarction is higher among women than among men after adjustment for age and other prognostic factors. We hypothesized that younger, but not older, women have higher mortality rates during hospitalization than their male peers. METHODS: We analyzed data on 384,878 patients (155,565 women and 229,313 men) who were 30 to 89 years of age and who had been enrolled in the National Registry of Myocardial Infarction 2 between June 1994 and January 1998. Patients who had been transferred from or to other hospitals were excluded. RESULTS: The overall mortality rate during hospitalization was 16.7 percent among the women and 11.5 percent among the men. Sex-based differences in the rates varied according to age. Among patients less than 50 years of age, the mortality rate for the women was more than twice that for the men. The difference in the rates decreased with increasing age and was no longer significant after the age of 74 (P< 0.001 for the interaction between sex and age). Logistic-regression analysis showed that the odds of death were 11.1 percent greater for women than for men with every five-year decrease in age (95 percent confidence interval, 10.1 to 12.1 percent). Differences in medical history, the clinical severity of the infarction, and early management accounted for only about one third of the difference in the risk. After adjustment for these factors, women still had a higher risk of death for every five years of decreasing age (increase in the odds of death, 7.0 percent; 95 percent confidence interval, 5.9 to 8.1 percent). CONCLUSIONS: After myocardial infarction, younger women, but not older women, have higher rates of death during hospitalization than men of the same age. The younger the age of the patients, the higher the risk of death among women relative to men. Younger women with myocardial infarction represent a high-risk group deserving of special study.

Adult↗
PubMed1999

Jumping translocations involving chromosome 1q in a patient with Crohn disease and acute monocytic leukemia: a review of the literature on jumping translocations in hematological malignancies and Crohn disease.

A 36-year-old man with a 10-year history of Crohn disease (CD) presented with gross hematuria and blasts in his peripheral blood. A chromosome analysis revealed one normal cell and 33 abnormal cells. The stem line was 47,XY,+8. The multiple side lines also had a jumping translocation between chromosome 1q31-32 and 4, 8, 10, 17, and 18 terminal regions. A cytogenetic, morphologic, and immunophenotypic analysis of a bone marrow aspirate and biopsy demonstrated acute myeloid leukemia of monocytic lineage, AML-M5b. In this paper are reviewed (a) the unusual and rare phenomenon of jumping translocations in hematological malignancies and (b) leukemia in CD.

Adolescent↗
PubMed1999

Rating the appropriateness of coronary angiography, coronary angioplasty and coronary artery bypass grafting: the ACRE study. Appropriateness of Coronary Revascularisation study.

BACKGROUND: Previous studies investigating the appropriateness of invasive management of coronary disease had not reported the internal consistency of their ratings and may now be out of date. The aim of this study was to measure the influence of clinical factors on contemporary ratings of the appropriateness of coronary angiography, percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG) in the Appropriateness of Coronary Revascularisation (ACRE) study. METHODS: The Delphi-RAND technique was used, in which an expert panel (four cardiologists, three cardiothoracic surgeons, a general physician and a general practitioner), meeting in 1995, rated mutually exclusive indications (n = 2178 for angiography, n = 995 for PTCA and n = 984 for CABG). The main outcome measures were the appropriateness category (inappropriate, uncertain or appropriate) for each of the three procedures and treatment preference. RESULTS: For revascularization, the strongest determinant of inappropriateness was coronary anatomy. The odds ratio (OR) for inappropriate PTCA was 10.6 (95 per cent confidence interval (CI) 4.8-23.5) for the effect of left main stem or three-vessel disease versus single-vessel disease, and for CABG it was 0.06 (95 per cent CI 0.03-0.15). The number of diseased vessels was strongly related to preference for medical, PTCA or CABG treatment (p for linear trend <0.001). Mild versus severe anginal symptoms were associated with inappropriate angiography (OR 2.0 (95 per cent CI 0.9-9.8), although this effect was stronger when only the cardiologists' ratings were considered (OR 10.1 (95 per cent CI 2.4-42.6)). CONCLUSION: These are the first UK ratings of appropriateness covering all three procedures. The associations with clinical factors provide evidence of the internal consistency of these ratings. Prospective validation of these ratings against clinical outcomes is under way in the ACRE study.

Aged↗
PubMed1998

A prospective comparison of the costs of reusable and limited-reuse laparoscopic instruments.

OBJECTIVE: To compare the cost and performance of 2 types of laparoscopic instrumentation: reusable laparoscopic hook cautery instruments and curved scissors, or limited-reuse laparoscopic hook cautery instruments and curved scissors. DESIGN: A randomized trial. SETTING: The operating room of a tertiary care hospital. METHOD: All general surgeons performing laparoscopic procedures at the hospital were randomized to be supplied with either reusable or limited-reuse hook cautery and curved scissors. Instrument use was recorded, together with principal outcome measures. OUTCOME MEASURES: Life expectancy of the instruments, the number of cases for which they were used, the number, nature and cost of repairs, their purchase cost and surgeon satisfaction. RESULTS: Reusable hook cautery instruments were less expensive than their limited-reuse counterparts. Excellent surgeon satisfaction was reported with the use of this type of instrument. The limited-reuse curved scissors arm of the study was terminated early because of a breach in study protocol. CONCLUSIONS: Reusable hook cautery instruments were better than their limited-reuse counterparts. Rigorous attempts to compare the cost of laparoscopic instruments may be limited by their rapid evolution in design and the availability of many types of instruments on the market.

Attitude of Health Personnel↗
PubMed1997

Use and accuracy of state death certificates for classification of sudden cardiac deaths in high-risk populations.

In a large cohort of patients with known or suspected coronary disease, we evaluated the characteristics of 407 patients who died after hospital discharge and tested whether the state death certificate can be used to classify deaths as sudden cardiac versus nonsudden. Compared with a paramedic classification system based on heart rhythm, the death certificate-based classification resulted in a sensitivity that ranged from 78% to 85% and a specificity that ranged from 25% to 58%. We conclude that the death certificate can be used to identify cases of sudden cardiac death in patients at high risk; however, there is a substantial rate of false-positive sudden death classification.

Aged↗