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Biomedical subjects

J Williams

Publications and source records attributed to J Williams.

At least 109 records · Page 6Linked to original sources
PubMed2003

Post-splenectomy thrombocytopenia: implications for regional analgesia.

Hospital computerised records were reviewed to identify patients who had undergone splenectomy, then chart their platelet count before and for the 5 days after the operation. A pre-operative platelet count less than 100 x 10(9).l-1 occurred in 66% of leukaemia (n = 35), 56% of lymphoma (n = 41) and 5% of solid tumour (n = 39) patients. Platelet supplementation prior to epidural catheter insertion may reduce the risks of spinal bleeding. However, accidental catheter removal during a postoperative period of thrombocytopenia may lead to formation of an epidural haematoma. The lowest postoperative platelet count was less than 100 x 10(9).l-1 in 66% of leukaemia, 27% of lymphoma and 13% of solid tumour patients. Platelet counts varied considerably, so predicting an individual patient's postoperative nadir from the pre-operative count would be impossible. Consequently, placement of an epidural catheter in many of these patients could expose them to an increased risk of spinal bleeding if the catheter is removed accidentally.

Adolescent↗
PubMed2003

Children with a tracheostomy: experience of their carers in school.

OBJECTIVE: Tracheostomies in children are increasingly performed for chronic medical conditions. There are no published studies reporting the experience of children with a tracheostomy in school. Such information would be valuable in planning the care and education of these children. The aims of this study were to identify those children with a tracheostomy in Nottinghamshire schools and determine the support they were receiving. DESIGN, SETTING AND PARTICIPANTS: Questionnaire survey to families and school carers of 11 children with a tracheostomy. RESULTS: All children of school age were in full-time education (five mainstream, five special schools). One preschool child attended a Family Centre. Four had problems finding suitable carers, delaying return to school in three. Four parents were dissatisfied with aspects of the child's experience at school: two felt the teaching staff were unsupportive, one was unhappy with the care of the tracheostomy, and one had problems funding a carer. Ten out of 11 school carers were satisfied with their training; 10 would have liked regular update sessions. The amount of care required varied. Those with complex medical problems in a special school setting needed frequent care, and one had required admission to hospital from school. One child had time off school because of lack of carer availability. Those who were severely disabled had less time off school for ill health after the tracheostomy than before the tracheostomy. CONCLUSION: Children with tracheostomies can successfully and safely achieve full-time education in both mainstream and special schools. A dedicated multidisciplinary team, including input from the parents, is essential to achieve this goal. Regular revision of skills and information sessions for the teaching staff would be beneficial.

Adolescent↗
PubMed2003

Altered arousal response in infants exposed to cigarette smoke.

AIMS: A failure of the arousal mechanism is a key feature in the apnoea theory for sudden infant death syndrome (SIDS). In infants studied at an age when the incidence of SIDS is highest, we evaluated whether in utero smoke exposed infants have altered arousal response to standardised auditory stimuli, and/or sleep pattern, as recorded on overnight complex sleep polysomnography. METHODS: A standardised sequence of audiology stimuli was applied binaurally to 20 in utero smoke and non-smoke exposed infants aged 8-12 weeks during a rapid eye movement (REM) and NREM epoch, in a controlled (temperature, position, pacifier use, noise) sleep environment. Infants were monitored for 10-12 hours using complex sleep polysomnography. RESULTS: Five infants exposed to in utero tobacco smoke did not have behavioural arousal response, whereas all non-smoke exposed infants aroused during NREM (p = 0.016). There was, however, no difference in REM sleep, and the groups did not differ in routine overnight complex sleep polysomnography parameters. CONCLUSION: At the age when the incidence of SIDS is at its peak, infants of smoking mothers are less rousable than those of non-smoking mothers in NREM sleep; this may partly explain why such infants are more at risk of SIDS.

Adult↗
PubMed2003

Pattern reversal visual evoked potentials as a measure of visual pathway pathology in multiple sclerosis.

BACKGROUND: Pattern reversal visual evoked potentials (PRVEPs) have a well-documented role in diagnosis of multiple sclerosis (MS), but their value as a visual function surrogate remains controversial. METHODS: We evaluated PRVEP in 37 patients with MS who were participating in a long-term follow-up study following a phase III trial of interferon beta-1a (Avonex). Patients were examined to determine the Kurtzke Extended Disability Status Score (EDSS), multiple sclerosis functional composite (MSFC), contrast letter acuity (CLA), and had cranial MRI scans to determine whole brain atrophy (BPF). PRVEP was evaluated for P100 latency, amplitude, and waveform morphology. Two summary scores were created: for Score A, abnormal latencies, morphologies, and amplitudes of each individual eye were added; for Score B, abnormal latencies, morphologies, and amplitude ratio between eyes was determined. Sixteen patients in this group also had PRVEP at the time they enrolled in the clinical trial, eight years previously. RESULTS: At the follow-up exam, over 75% of patients had abnormal PVEP parameters while visual acuity (VA) was abnormal only in 59%. Increased PRVEP latency over the eight-year period correlated with deterioration assessed by EDSS (P = 0.006), BPF (P = 0.0001), and MSFC (P = 0.0041). Score A was significantly correlated with EDSS, BPF, CLA, cognitive function, and quality of life assessed with the Sickness Impact profile. No correlation was seen with the MSFC. CONCLUSIONS: The results indicate that PRVEP measures MS-related pathology, and can provide not only diagnostic but also prognostic information during evaluation of MS patients.

Evoked Potentials, Visual↗
PubMed2003

Measurement of serum 'free' or 'easily dissociable' insulin-like growth factor-1.

BACKGROUND: Serum insulin-like growth factor-1 (IGF-1) exists as ternary and binary complexes, and as the free hormone. An immunometric assay for 'free IGF-1' or 'easily dissociable IGF-1' has been described, although its use has not been widely assessed. METHODS: The assay was assessed using the serum concentration/dilution test and by determining the relationship of the measured free hormone to the total hormone/binding protein ratio. RESULTS: In six serum pools the measured free IGF-1 did not remain constant on concentration/dilution of the sample. However there was a significant correlation between the measured free IGF-1 and total IGF-1 (P < 0.001) and between total IGF-1/IGF binding protein-3 ratio (P < 0.001). DISCUSSION: Although the assay failed the serum concentration/dilution test, there was still a significant relationship to the total hormone/binding protein ratio. It is possible that the serum dilution test is inappropriate to such a complex system or that the assay does not measure the free fraction. It is suggested that, though more cumbersome, it should be referred to as 'easily dissociable' IGF-1 as suggested by the manufacturers.

Chemistry, Clinical↗
PubMed2003

Appendicular fractures: a significant problem among institutionalized adults with developmental disabilities.

A high incidence of nontraumatic fracture in adults with developmental disabilities living in a state-run facility was described. Risk factors for fracture, including bone mineral density (BMD), were investigated to determine whether people at highest risk for fracture could be prospectively identified. There was a 7.3% incidence of fracture among 391 adults. Risk factors were examined for 23 residents with fracture and 23 age-, race-, and gender-matched controls. There was a trend for antiepileptic medication usage to be associated with fractures. Estimated BMD by heel ultrasound did not predict fracture; however, values were much lower than those for the general population. Fractures and low BMD are significant problems among institutionalized adults with severe developmental disabilities. Further studies to identify therapies to prevent fractures are warranted.

Adolescent↗
PubMed2002

Measurement of B(D+-->K(*0)l(+)nu(l)).

Using 13.53 fb(-1) of CLEO data, we have measured the ratios of the branching fractions R(+)(e),R(+)(mu) and the combined branching fraction ratio R(+)(l), defined by R(+)(l)=[B(D+-->K(*0)l(+)nu(l))]/[B(D+-->K-pi(+)pi(+))]. We find R(+)(e)=0.74+/-0.04+/-0.05, R(+)(mu)=0.72+/-0.10+/-0.05, and R(+)(l)=0.74+/-0.04+/-0.05, where the first and second errors are statistical and systematic, respectively. The known branching fraction B(D+-->K-pi(+)pi(+)) leads to B(D+-->K(*0)e(+)nu(e))=(6.7+/-0.4+/-0.5+/-0.4)%, B(D+-->K(*0)mu(+)nu(mu))=(6.5+/-0.9+/-0.5+/-0.4)%, and B(D+-->K(*0)l(+)nu(l))=(6.7+/-0.4+/-0.5+/-0.4)%, where the third error is due to the uncertainty in B(D+-->K-pi(+)pi(+)).

Journal Article↗
PubMed2002

Global air pollution crossroads over the Mediterranean.

The Mediterranean Intensive Oxidant Study, performed in the summer of 2001, uncovered air pollution layers from the surface to an altitude of 15 kilometers. In the boundary layer, air pollution standards are exceeded throughout the region, caused by West and East European pollution from the north. Aerosol particles also reduce solar radiation penetration to the surface, which can suppress precipitation. In the middle troposphere, Asian and to a lesser extent North American pollution is transported from the west. Additional Asian pollution from the east, transported from the monsoon in the upper troposphere, crosses the Mediterranean tropopause, which pollutes the lower stratosphere at middle latitudes.

Aerosols↗
PubMed2002

Improved measurement of /V(cb)/ using B-->D*l nu decays.

We determine the weak coupling /V(cb)/ between the b and c quarks using a sample of 3 x 10(6) BB; events in the CLEO detector at the Cornell Electron Storage Ring. We determine the yield of reconstructed B-->D*l nu; decays as a function of w, the boost of the D* in the B rest frame, and from this we obtain the differential decay rate d Gamma/dw. By extrapolating d Gamma/dw to w=1, the kinematic end point at which the D* is at rest relative to the B, we extract the product /V(cb)/F(1), where F(1) is the form factor at w=1. Combined with theoretical results for F(1) we determine /V(cb)/=0.0469+/-0.0014(stat)+/-0.0020(syst)+/-0.0018(theor).

Journal Article↗
PubMed2002

Improved measurement of Vub with inclusive semileptonic B decays.

We report a new measurement of the Cabibbo-Kobayashi-Maskawa parameter Vub made with a sample of 9.7 x 10(6) BB- events collected with the CLEO II detector. Using heavy quark theory, we combine the observed yield of leptons from semileptonic B decay in the end-point momentum interval 2.2-2.6 GeV/c with recent CLEO II data on B-->X(s)gamma to find Vub = (4.08+/-0.34+/-0.44+/-0.16+/-0.24)x10(-3), where the first two uncertainties are experimental and the last two are from theory.

Journal Article↗
PubMed2002

Studies of the efficacy of a novel intranasal vaccine against feline bordetellosis.

A novel intranasal vaccine against disease caused by Bordetella bronchiseptica in cats was tested in a series of three experiments. In the first experiment a vaccinated group and an unvaccinated control group of kittens were challenged by the aerosol route with virulent B bronchiseptica three weeks after they had been vaccinated. The control kittens developed upper respiratory tract signs typical of feline B bronchiseptica infection, including rhinitis, a serous ocular and nasal discharge, fever, sneezing and coughing. The mean (sd) clinical score for the cats in the unvaccinated control group was 19.5 (5.4) compared with 1.53 (1.9) for the vaccinated group. In the second experiment vaccinated kittens were challenged with virulent B bronchiseptica 72 hours after they were vaccinated. Their mean clinical score was 2.76 (2.62) compared with 13.4 (3.33) for the control group. In the final experiment, vaccinated and unvaccinated control cats were challenged after six or 12 months. After six months the mean clinical scores were 13.9 (4.7) for the control group, compared with 1.33 (1.56) for the vaccinated group, and after 12 months the scores were 9.92 (5.79) for the control group compared with 0.92 (0.89) for the vaccinated group.

Administration, Intranasal↗
PubMed2002

Search for CP violation in tau--> K(pi)nu(tau) decays.

We search and find no evidence for CP violation in tau decays into the K(pi)nu(tau) final state. We provide limits on the imaginary part of the coupling constant Lambda describing a relative contribution of the CP violating processes with respect to the standard model to be -0.172<Im(Lambda)<0.067 at 90% C.L.

Journal Article↗
PubMed2002

Observation of exclusive B --> D(*)K(*-) decays.

We report the first observation of the exclusive decays B-->D((*))K(*-), using 9.66 x 10(6) BB pairs collected at the Upsilon(4S) with the CLEO detector. We measure the following branching fractions: B(B--->D(0)K(*-)) = (6.1+/-1.6+/-1.7)x10(-4), B(B(0)-->D(+)K(*-)) = (3.7+/-1.5+/-1.0)x10(-4), B(B(0)-->D(*+)K(*-)) = (3.8+/-1.3+/-0.8)x10(-4), and B(B--->D(*0)K(*-)) = (7.7+/-2.2+/-2.6)x10(-4). The B-->D(*)K(*-) branching ratios are the averages of those corresponding to the 00 and 11 helicity states. The errors shown are statistical and systematic, respectively.

Journal Article↗
PubMed2002

Observation of B(0) --> D0pi(0) and B(0) -->D(*0)pi(0).

We have studied the color-suppressed hadronic decays of neutral B mesons into the final states D*0pi(0). Using 9.67 x 10(6) BB pairs collected with the CLEO detector, we observe the decays B( 0) --> D0pi(0) and B( 0) -->D(*0)pi(0) with the branching fractions BB( 0) -->D0pi(0)) = (2.74(+0.36)(-0.32) +/- 0.55)x10(-4) and BB( 0) -->D(*0)pi(0)) = (2.20(+0.59)(-0.52) +/- 0.79)x10(-4). The first error is statistical and the second systematic. The statistical significance of the D0pi(0) signal is 12.1sigma ( 5.9sigma for D(*0)pi(0)). Utilizing the B( 0) -->D*0)pi(0) branching fractions we determine the strong phases delta(I,D(*)) between isospin 1/2 and 3/2 amplitudes in the Dpi and D*pi final states to be cosdelta(I,D) = 0.89 +/-0.08 and cosdelta(I,D*) = 0.89 +/- 0.08, respectively.

Journal Article↗
PubMed2002

Comparison of two treatments for traumatic stress: a community-based study of EMDR and prolonged exposure.

This pilot study compared the efficacy of two treatments for postraumatic stress disorder (PTSD): Eye Movement Desensitization and Reprocessing (EMDR) and Prolonged Exposure (PE). Data were analyzed for 22 patients from a university-based clinic serving the outside community (predominantly rape and crime victims) who completed at least one active session of treatment after three preparatory sessions. Results showed both approaches produced a significant reduction in PTSD and depression symptoms, which were maintained at three-month follow-up. Successful treatment was faster with EMDR as a larger number of people (7 of 10) had a 70% reduction in PTSD symptoms after three active sessions compared to 2 of 12 with PE. EMDR appeared to be better tolerated as the dropout rate was significantly lower in those randomized to EMDR versus PE (0 of 10 vs. 3 of 10). However all patients who remained in treatment with PE had a reduction in PTSD scores. Finally, Subjective Units of Distress (SUDS) ratings decreased significantly during the initial session of EMDR, but changed little during PE. Postsession SUDS were significantly lower for EMDR than for PE. Suggestions for future research are discussed.

Cognitive Behavioral Therapy↗
PubMed2002

A phase I study of weekly topotecan and Paclitaxel in previously treated epithelial ovarian carcinoma patients.

OBJECTIVE: We have previously reported on the feasibility of weekly topotecan as single-agent therapy in previously treated patients with ovarian cancer. The objective of this study was to assess the maximum tolerated dose (MTD) of weekly bolus intravenous (IV) topotecan combined with weekly paclitaxel in a comparable patient population. METHODS: Previously treated ovarian cancer patients with measurable disease and/or elevated cancer antigen 125 (CA-125) received (as second-line or third-line therapy) weekly 30-min bolus IV topotecan starting at 2 mg/m(2) combined with weekly paclitaxel starting at a dose of 60 mg/m(2). In this intrapatient dose-escalation study, topotecan and paclitaxel were escalated in parallel until the MTD was reached, defined as the first dose level at which >or= 2 of 6 patients experienced dose-limiting toxicity. RESULTS: Twenty-one of 26 patients were evaluable for toxicity and received a total of 306 weeks of therapy (median, 13 weeks; range, 5 to 33 weeks). No significant dose-limiting toxicity was observed up to a weekly bolus IV topotecan dose of 3 mg/m(2) and a concurrent paclitaxel dose of 80 mg/m(2). The MTD was topotecan 3.5 mg/m(2) plus 90 mg/m(2) paclitaxel. The dose-limiting toxicities included anemia and fatigue, with 10 of 21 patients receiving epoetin alfa for grade 3 or 4 anemia; only 1 patient required a blood transfusion. Two patients had a treatment delay of at least 1 week and only 1 patient required a dose reduction to maintain the weekly schedule. CONCLUSIONS: Based on the results of this study, the recommended initial dose for this novel regimen is topotecan 3 mg/m(2) and paclitaxel 80 mg/m(2). Further investigation of the efficacy of weekly topotecan plus paclitaxel in less heavily pretreated patients is warranted.

Adult↗