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Biomedical subjects

A Lamb

Publications and source records attributed to A Lamb.

At least 19 recordsLinked to original sources
PubMed2003

Differential deficits in expression recognition in gene-carriers and patients with Huntington's disease.

Previous studies in symptomatic patients and asymptomatic gene-carriers of Huntington's disease (HD) reported a differential deficit in the recognition of facial expressions of disgust. This impairment may point to involvement of the basal ganglia in the recognition of disgust. In this study, we compared the performance of 20 patients with symptoms of HD, 20 gene-carriers of HD and 20 healthy controls on two tests of facial expressions in order to further investigate the role of the basal ganglia in disgust recognition. Recognition of fear, rather than disgust, was most severely impaired in the patients, who were also impaired at recognising expressions of anger, disgust and sadness. Direct testing for a differential deficit in disgust at the group level (and at the level of individual HD cases) revealed that the patients were in fact significantly more impaired on the other negative expressions than on disgust. The gene-carriers were not impaired on any expression, although there was a trend for the gene-carriers to be poorer at recognising fearful faces than the controls. We argue that the expression recognition performance of the patients and gene-carriers simply reflects differences in task difficulty, rather than dysfunction of any mechanisms dedicated to specific emotions. In contrast to previous studies in patients or gene-carriers of HD, our findings provide no evidence for a role of the basal ganglia in the recognition of disgust and cast doubt on whether results from HD patients and gene-carriers can be used in support of a double dissociation between recognition of disgust and fear.

Adult↗
PubMed2001

Experience with an XML/HTTP-based federative approach to develop a hospital-wide clinical information system.

The authors present a two-year experience with an approach aimed at federating applications into a component-based hospital-wide clinical information system. Recognizing the need for better integration, clearer separation of knowledge from applications, as well as the necessity to respect and integrate the diversity of roles in a healthcare network, a strategy was implemented that included the development of a shared vision, organizational changes to promote appropriation at all levels, and the elaboration and maintenance of a common architecture and terminology by an instrumental technical group. Choices for federative technologies were in part based on their level of acceptance and potential to evolve. XML was used as the syntactic framework and HTTP as the transfer protocol. Within twelve months, the shared vision was developed, the architecture was specified, the key central components implemented, incorporated into the applications, and applications teams started producing shareable services using XML and HTTP.

Hospital Information Systems↗
PubMed2000

Rapid prenatal diagnosis of chromosome aneuploidies by interphase fluorescence in situ hybridization: a one-year clinical experience with high-risk and urgent fetal and postnatal samples.

OBJECTIVES: To evaluate the clinical utility of rapid prenatal and postnatal detection of common chromosome aneuploidies by interphase fluorescence in situ hybridization (FISH) analysis with DNA probes. DESIGN: Four hundred and seventy-seven high-risk and/or urgent amniotic fluid, chorionic villus and fetal and postnatal blood samples were prospectively examined by FISH with probes specific for chromosomes 13, 18, 21, X, and Y and results were reported within 48 hours. All FISH results were followed by conventional chromosome analysis, if possible. SETTING: Cytogenetic service laboratory at the tertiary referral center, Rigshospitalet in Copenhagen. MAIN OUTCOME MEASURES: The fraction of clinically significant chromosome aneuploidies that was detected by FISH analysis, and the fraction of terminations that was based on FISH and ultrasound results rather than on conventional cytogenetic results. RESULTS: The FISH assay detected 76% of the clinically significant chromosome abnormalities as determined by subsequent cytogenetic analysis. Seventy-two percent of the terminations of the chromosomally abnormal pregnancies were based on FISH and ultrasound results rather than on conventional cytogenetic results. CONCLUSION: FISH analysis is a clinically useful adjunctive tool to conventional pre- and postnatal cytogenetic analysis. The assay rapidly detects the majority of clinically significant chromosome abnormalities, thus facilitating difficult pre- and postnatal clinical decisions.

Adult↗
PubMed1999

Patients' perceptions of the Odstock Dropped Foot Stimulator (ODFS).

OBJECTIVE: To determine the perceived benefit, pattern and problems of use of the Odstock Dropped Foot Stimulator (ODFS) and the users' opinion of the service provided. DESIGN: Questionnaire sent in a single mailshot to current and past users of the ODFS. Returns were sent anonymously. SETTING: Outpatient-based clinical service. SUBJECTS: One hundred and sixty-eight current and 123 past users with diagnoses of stroke (CVA), multiple sclerosis (MS), incomplete spinal cord injury (SCI), traumatic brain injury (TBI) and cerebral palsy (CP). INTERVENTION: Functional electrical stimulation (FES) to correct dropped foot in subjects with an upper motor neuron lesion, using the ODFS. MAIN OUTCOME MEASURES: Purpose-designed questionnaire. RESULTS: Return rate 64% current users (mean duration of use 19.5 months) and 43% past users (mean duration of use 10.7 months). Principal reason cited for using equipment was a reduction in the effort of walking. Principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties and deteriorating mobility. There were some problems with reliability of equipment. Level of service provided was thought to be good. CONCLUSION: The ODFS was perceived by the users to be of considerable benefit. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES-based orthoses.

Adult↗
PubMed1998

Gain of 9p in the pathogenesis of polycythemia vera.

Polycythemia vera (PV) is a clonal stem cell disorder characterized by excessive erythrocyte production, resulting in absolute erythrocytosis. No specific structural chromosomal abnormalities have been reported in PV to date. We have observed two cases of PV with an extra i(9)(p10) as the sole anomaly, and FISH analysis using a 9p-specific chromosome microdissection probe showed that two other PV patients previously identified as having an add(18p) and an add(1p) as the primary changes actually carried a der(18)t(9;18)(p12;p11.2) and a der(1)t(1;9)(p12;p12), respectively. The same FISH assay was employed to evaluate domain signals on interphase cells of 15 more cases of PV with normal karyotypes and five normal controls. Two patients were observed with a significant increase in the percentage of cells with three domain signals. Our results strongly indicate that an additional i(9)(p10) is a new and recurrent primary chromosome anomaly in PV, and, in consideration of trisomy 9 being one of the most common anomalies in PV, amplification of a gene or genes on 9p, but not on 9q, may play a crucial role in the pathogenesis of PV.

Adult↗
PubMed1998

Investigation and modelling of the surface dose from linear accelerator produced 6 and 10 MV photon beams.

The radiation reaction from the surface dose to a patient's skin is clinically important as an indicator of tolerance to treatment and is frequently the most visible side-effect from external beam radiotherapy. To quantify surface dose, its build-up was investigated in a solid water phantom over a range of field sizes, source to skin distances, wedge angles and beam shaping conditions. These data were analysed and used to produce an empirical model of the effect of these factors which predicted surface dose to within 5% under test conditions. The effects of changing treatment techniques was investigated by comparing fixed to dynamic wedges, and multileaf collimator (MLC) with alloy blocks. It was found that the MLC reduced the surface dose relative to alloy blocks but that dynamic wedges made no change relative to open fields. Fixed wedges reduced the relative surface dose as a consequence of beam hardening. It is hoped that routine clinical use of the model to calculate skin dose will increase awareness of situations in which the skin sparing effect of modern linear accelerators may be compromised.

Equipment Design↗
PubMed1997

Aeromonas popoffii sp. nov., a mesophilic bacterium isolated from drinking water production plants and reservoirs.

We examined the taxonomic position of seven Aeromonas isolates, recovered from Flemish and Scottish drinking water production plants and reservoirs, which were previously recognized by numerical analysis of genomic AFLP fingerprints as members of an unknown Aeromonas taxon that most closely resembled the species Aeromonas bestiarum (DNA hybridization group [HG] 2). The new phenotypic and DNA-DNA hybridization data obtained in this study show that the A. bestiarum-like strains constitute a separate Aeromonas species, for which the name Aeromonas popoffii sp. nov. is being proposed. The new species exhibited an internal DNA relatedness ranging from 79 to 100% and was 22 to 63% related to the type or reference strains of other Aeromonas spp. The highest DNA binding values were determined with A. bestiarum (51 to 63%), followed by Aeromonas hydrophila sensu stricto (HG1; 50 to 60%) and Aeromonas salmonicida (HG3; 39 to 55%). Although fingerprints generated by ribotyping and cellular fatty acid analysis often were highly similar, minor differences between the respective fingerprints were of significance for the differentiation of A. popoffii from its closest taxonomic neighbors, HG1, HG2, and HG3. Phenotypically, all seven strains of A. popoffii were positive for acid and gas production from D-glucose and glycerol, growth in KCN broth, arginine dihydrolase, DNase, Voges-Proskauer reaction, and resistance to vibriostatic agent O/129 and ampicillin but displayed negative reactions for production of urease, tryptophan deaminase, ornithine decarboxylase, and lysine decarboxylase (LDC). None of the strains displayed strong hemolytic activity. The lack of D-sucrose fermentation and LDC production and the ability to utilize DL-lactate as the sole energy and carbon source were useful characteristics for the biochemical separation of A. popoffii from A. bestiarum. Other Aeromonas spp. could be differentiated phenotypically from the new species by at least two features. The chromosomal G+C content of A. popoffii ranges from 57.7 to 59.6 mol%. Strain LMG 17541 is proposed as the type strain.

Aeromonas↗
PubMed1995

Do protective devices prevent needlestick injuries among health care workers?

OBJECTIVES: To determine the effectiveness and direct of two protective devices-a shielded 3 ml safety syringe (Safety-Lok; Becton Dickinson and Co., Becton Dickinson Division, Franklin Lakes, N.J.) and the components of a needleless IV system (InterLink; Baxter Healthcare Corp., Deerfield, Ill.)--in preventing needlestick injuries to health care workers. DESIGN: Twelve-month prospective, controlled, before-and-after trial with a standardized questionnaire to monitor needlestick injury rates. SETTING: Six hospital inpatient units, consisting of three medical units, two surgical units (all of which were similar in patient census, acuity, and frequency of needlesticks), and a surgical-trauma intensive care unit, at a 900-bed urban university medical center. PARTICIPANTS: All nursing personnel, including registered nurses, licensed practical nurses, nursing aides, and students, as well as medical teams consisting of an attending physician, resident physician, interns, and medical students on the study units. INTERVENTION: After a 6-month prospective surveillance period, the protective devices were randomly introduced to four of the chosen study units and to the surgical-trauma intensive care unit. RESULTS: Forty-seven needlesticks were reported throughout the entire study period, 33 in the 6 months before and 14 in the 6 months after the introduction of the protective devices. Nursing staff members who were using hollow-bore needles and manipulating intravenous lines accounted for the greatest number of needlestick injuries in the pre-intervention period. The overall rate of needlestick injury was reduced by 61%, from 0.785 to 0.303 needlestick injuries per 1000 health care worker-days after the introduction of the protective devices (relative risk = 1.958; 95% confidence interval, 1.012 to 3.790; p = 0.046). Needlestick injury rates associated with intravenous line manipulation, procedures with 3 ml syringes, and sharps disposal were reduced by 50%; however, reductions in these subcategories were not statistically significant. No seroconversions to HIV-1 or hepatitis B virus seropositivity occurred among those with needlestick injuries. The direct cost for each needlestick prevented was $789. CONCLUSIONS: Despite an overall reduction in needlestick injury rates, no statistically significant reductions could be directly attributed to the protective devices. These devices are associated with a significant increase in cost compared with conventional devices. Further studies must be concurrently controlled to establish the effectiveness of these devices.

Direct Service Costs↗
PubMed1993

Exogenously administered alpha-bungarotoxin binds to embryonic chick spinal cord: implications for the toxin-induced arrest of naturally occurring motoneuron death.

Administration of alpha-bungarotoxin and other curare-like drugs during embryogenesis arrests motoneuron death which normally occurs in the spinal cord from day 6 to day 10 of embryogenesis. The accepted explanation is that such motoneuron rescue is mediated by inhibition of neuromuscular transmission following the blockade of nicotinic cholinoceptors at the neuromuscular junction. In this study we investigated a further possibility, namely that motoneuron rescue might also involve the blockade of alpha-bungarotoxin-sensitive sites within the spinal cord. The kinetic profile of [125I]alpha-bungarotoxin binding was examined in the brachial and lumbar regions of chick spinal cord at embryonic day 15. Binding was specific and apparently saturable within the range 1-34 nM reaching a maximum after 45 min. Specific binding involved a single class of non-interacting sites with a KD of 8.0 nM and a Bmax of 106 +/- 12 fmol/mg of protein. Nicotine displaced specific [125I]alpha-bungarotoxin binding in a concentration-dependent manner. Furthermore, specific binding dissociated slowly in the absence of nicotine. Autoradiographs localizing [125I]alpha-bungarotoxin binding in embryonic spinal cord revealed that, at embryonic day 15, specific toxin binding sites could be detected throughout the gray matter. In contrast, at embryonic day 6, the ventral horn contained the majority of specific binding sites. Exogenously administered [125I]alpha-bungarotoxin reached and bound to nicotine-sensitive sites in the spinal cord at embryonic day 7. To conclude, these data demonstrate that central nicotine-sensitive sites which bind [125I]alpha-bungarotoxin in a saturable and specific manner were present at the beginning of the critical motoneuron death phase of neurogenesis and that they were accessible to exogenously administered toxin. It is proposed that the [125I]alpha-bungarotoxin binding characterized here is to a class of putative alpha-bungarotoxin-sensitive nicotinic cholinoceptors. These studies raise the possibility that alpha-bungarotoxin blockade of such putative nicotinic cholinoceptors within the spinal cord may contribute to toxin-induced arrest of naturally occurring motoneuron death.

Animals↗
PubMed1992

The swab rack--an outdated ritual.

The risk of Theatre Staff becoming infected from blood borne viruses such as HIV and Hepatitis B is steadily increasing. Sir David Cox's report (1988) predicted that the number of people infected with HIV by the end of 1987 would be between 20,000 and 50,000. Although these predictions are now thought to be more accurately estimated between 12,000 and 26,000, the number of people developing Aids is still expected to rise at an alarming rate. The precautions taken within the Theatre Department to reduce this risk are becoming transparently inadequate. It is no longer sufficient--or acceptable practice--to only be vigilant in avoiding blood contamination if the patient falls within a certain 'high risk' category. A happily married, middle aged woman may also be a virus carrier, particularly considering the long dormancy the HIV virus can exhibit before being detectable. It must be assumed that everyone is a potential carrier and the same precautionary measures taken for every patient, regardless of their past history, or present appearance.

Blood Loss, Surgical↗
PubMed1991

The product of the KIN1 locus in Saccharomyces cerevisiae is a serine/threonine-specific protein kinase.

The catalytic domain (30 kDa) of all protein kinases can be aligned for maximum homology, thereby revealing both invariant and highly conserved residues. The KIN1 locus from Saccharomyces cerevisiae was isolated by hybridization to a degenerate oligonucleotide encoding the conserved protein kinase domain, DVWSFG. The predicted amino acid sequence revealed significant homology to the catalytic domain of protein kinases. Using antibodies raised against a bacterial LacZ/KIN1 fusion protein, we have identified by immunoprecipitation the yeast KIN1 gene product as a 145,000 dalton protein (p145KIN1). In exponentially growing yeast cells, the KIN1 protein is phosphorylated primarily on serine residues. The gene product of KIN1 was shown to be a serine/threonine-specific protein kinase in immune complexes, as determined by the transfer of label from [gamma-32P]ATP to either pp145KIN1 or to an exogenously added substrate, alpha-casein. The optimal metal ion concentration in this assay was 20 mM-MnCl2. Subsequent phosphoamino acid analysis of the radiolabelled product, pp145KIN1, demonstrated that this autophosphorylation was specific for serine/threonine residues. There is no apparent difference between wild-type cells and cells containing a disrupted KIN1 gene. The biochemical characterization of protein kinases in simple eukaryotes such as yeast will aid us in determining the role of phosphorylation in cellular growth and physiology.

Amino Acid Sequence↗