Measuring glycated haemoglobin.
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Chromatography, High Pressure Liquid↗
Biomedical subjects
S Jones
Publications and source records attributed to S Jones.
Neurotransmitter modulation of calcium channels is dependent on the charge carrier used in the recording of currents.
Currents through calcium channels were recorded using calcium, barium and strontium as charge carriers in NG108-15 cells. The mean normalised peak current amplitude at 0 mV was not significantly different between the charge carriers; however, the sustained component (measured at the end of the 500 ms command step) was ca. 3 times larger in barium and strontium. Further, the inhibition by acetylcholine or noradrenaline, although the same at the peak of the current envelope, was significantly greater on the sustained portion of the current for barium and strontium. Increasing internal calcium-buffering (to reduce calcium-dependent inactivation with calcium as the charge carrier) did not increase the amount of inhibition of the sustained portion of current. These results suggest a cautious approach to analysis of neurotransmitter modulation of calcium currents using other charge carriers than calcium.
Acetylcholine↗
Cost implications of the British Pacing and Electrophysiology Group's recommendations for pacing.
OBJECTIVE: To compare present pacing practice with the recommendations recently published by the British Pacing and Electrophysiology Group and to assess the increase in annual budget required to implement these recommendations in a regional cardiothoracic unit. DESIGN: Retrospective analysis of pacemaker implantation for 1991 with calculation of the costs required to implement the group's recommendations based on average 1991 costs of the types of pacing generators and electrode leads used. SETTING: Regional cardiothoracic unit for South West Thames Health Authority. PATIENTS: 433 consecutive patients receiving permanent pacemaker generators: 76 (18%) with sinus node disease; 270 (62%) with atrioventricular block; 25 (6%) with both sinus node disease and atrioventricular block; 59 (14%) with chronic atrial fibrillation and atrioventricular block; and 3 (1%) with carotid sinus or malignant vasovagal syndromes. RESULTS: Only 102 (24%) patients received pacemaker generators recommended by the British Pacing and Electrophysiology Group; however, 355 (82%) patients were older than 65 years, and 264 (61%) were aged 75 or over. The cost of hardware for pacing was 462,885 pounds. Using generators as recommended would have cost 810,525 pounds for "optimal" systems (an increase of 75%) and 710,750 pounds for "alternative" systems (an increase of 54%). These increases would have been considerably reduced by limiting the use of sophisticated pacing to younger patients (aged under 75). Further savings could be made by using the least expensive pacing models available. CONCLUSIONS: Implementing these recommendations should reduce morbidity related to bradyarrhythmia but will lead to major increases in pacing costs. Age and patients' expected activity may be used to select simple pacing systems and thus to contain cost. More research is needed to determine which patient groups will benefit most from complex pacing systems.
Adult↗
Modelling coccidial infection in chickens: emphasis on vaccination by in-feed delivery of oocysts.
Trickle immunization of poultry by incorporating wildtype strains of coccidia in the feed has been shown to be an effective and practical means of controlling coccidiosis. Here we develop a mathematical model of the life cycle of Eimeria tenella and estimate the model parameters from extant experimental studies. Numerical solutions of the model compare well with experiment. The model provides quantitative estimates of the required trickle immunization hitherto only available after extensive time-consuming trials.
Animal Feed↗
Syntheses, resolution, and structure-activity relationships of potent acetylcholinesterase inhibitors: 8-carbaphysostigmine analogues.
The synthesis of a series of 1,2,3,3a,8,8a-hexahydroindeno[2,1-b]pyrrole 5-alkylcarbamates and their resolution are reported. These compounds are structurally related to physostigmine with substitution of a methylene group in place of the NMe group at position 8 of physostigmine. Many of these 8-carbaphysostigmine analogues are more potent acetylcholinesterase inhibitors in vitro and less toxic in vivo than physostigmine. The (-)-enantiomer (e.g., 1d and 1g) possessing the same absolute configuration at C3a and C8a as that of physostigmine, is about 6 to 12-fold more potent at inhibiting acetylcholinesterase than the corresponding (+)-enantiomer (e.g., 1e and 1h).
Animals↗
The influence of levodopa on gastric emptying in healthy elderly volunteers.
Paracetamol absorption and 99Tc-DTPA measurements have been used to determine the influence of levodopa on gastric emptying in 8 healthy elderly volunteers. In the absence of levodopa 7 subjects showed a rapid gastric emptying pattern by gamma-camera and a single major peak in the plasma concentration-time curve of paracetamol. One subject showed two rapid phases of gastric emptying separated by a period of negligible emptying and had 2 separate peaks in the paracetamol plasma concentration-time curve. In the presence of levodopa, the gamma-camera data for 6 subjects showed a pattern of gastric emptying consisting of 2 rapid phases separated by a plateau. In each case secondary peaks in the plasma concentration-time curve of paracetamol occurred about 30 min after the end of the plateau. The time to 90% emptying on the gamma scan was increased significantly from 40 min to 65 min in the presence of levodopa. Comparison of the present data with those reported previously indicates that levodopa affects gastric emptying in the both elderly and young volunteers to a similar extent.
Acetaminophen↗
Perception, ontology, and naming in young children: commentary on Soja, Carey, and Spelke.
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Child, Preschool↗
The assessment of nucleotide sequence diversity by the polymerase chain reaction is highly reproducible.
The polymerase chain reaction (PCR) is often used to assess the diversity of viral nucleotide sequences present in various biological samples (e.g., blood and tissues). However, it is not clear how reproducible this approach may be. DNA was extracted from the peripheral blood lymphocytes of a macaque that had been infected, experimentally, with SIVmac251-32H 6 months previously. The nef gene was then amplified by the PCR on three separate occasions from this same template preparation. A panel of clones was prepared from the product of each PCR, the entire nef gene was sequenced and the sequences obtained compared with each other. Phenogram analysis revealed that within each panel the same degree of sequence diversity was observed between clones. Furthermore, when the sequences obtained from all three panels were compared, the overall sequence diversity observed was no greater than that observed for each panel individually. These data indicate that the analysis of sequence diversity in SIV 'quasi-species' populations by the PCR is reliable and, more important, reproducible.
Animals↗
CD-ROM source data uploaded to the operating and storage devices of an IBM 3090 mainframe through a PC terminal.
A powerful method of processing MEDLINE and CINAHL source data uploaded to the IBM 3090 mainframe computer through an IBM/PC is described. Data are first downloaded from the CD-ROM's PC devices to floppy disks. These disks then are uploaded to the mainframe computer through an IBM/PC equipped with WordPerfect text editor and computer network connection (SONNGATE). Before downloading, keywords specifying the information to be accessed are typed at the FIND prompt of the CD-ROM station. The resulting abstracts are downloaded into a file called DOWNLOAD.DOC. The floppy disks containing the information are simply carried to an IBM/PC which has a terminal emulation (TELNET) connection to the university-wide computer network (SONNET) at the Ohio State University Academic Computing Services (OSU ACS). The WordPerfect (5.1) processes and saves the text into DOS format. Using the File Transfer Protocol (FTP, 130,000 bytes/s) of SONNET, the entire text containing the information obtained through the MEDLINE and CINAHL search is transferred to the remote mainframe computer for further processing. At this point, abstracts in the specified area are ready for immediate access and multiple retrieval by any PC having network switch or dial-in connection after the USER ID, PASSWORD and ACCOUNT NUMBER are specified by the user. The system provides the user an on-line, very powerful and quick method of searching for words specifying: diseases, agents, experimental methods, animals, authors, and journals in the research area downloaded. The user can also copy the TItles, AUthors and SOurce with optional parts of abstracts into papers under edition. This arrangement serves the special demands of a research laboratory by handling MEDLINE and CINAHL source data resulting after a search is performed with keywords specified for ongoing projects. Since the Ohio State University has a centrally founded mainframe system, the data upload, storage and mainframe operations are free.
CD-ROM↗
A report of an international collaborative experiment to demonstrate the uniformity obtainable using DNA profiling techniques.
This paper describes a collaborative exercise intended to demonstrate whether uniformity of DNA profile results could be achieved between different European laboratories. It was shown that this goal can be obtained provided that a common protocol is followed (specifically the use of a common electrophoretic buffer as being the most important parameter). Generally, lower molecular weight loci (with lower molecular weight fragments) such as YNH24 perform better than higher molecular weight loci such as MS43a. The results of the exercise are discussed in relation to the objectives of the European DNA profiling group (EDNAP).
Autoradiography↗
The effect of a support group on grieving individuals' levels of perceived support and stress.
This study examined the effects of support group participation on bereaved individuals' levels of perceived support and stress. Using a single group pretest/posttest design, data were collected from a convenience sample of 21 grieving individuals who participated in 10 weekly support group sessions. Perceived stress decreased significantly (P less than .002) following support group participation. However, although perceived support increased, the change was not statistically significant. These findings indicate that a support group can be an effective intervention to decrease feelings of stress in bereaved individuals.
Adaptation, Psychological↗
Communication aids for children: procedures and problems.
This paper describes the organisation and procedures of the Communication Aids Centre for children at the Wolfson Centre, London, including a model for assessment and recommendation of appropriate aids, such as symbol charts, switches and speech synthesisers. Of the children seen over an 18-month period, most had cerebral palsy and two-thirds were wheelchair-dependent. Almost half were assessed before the age of five years. A detailed follow-up of nine children is presented which reveals how long children may have to wait for the provision of an aid in the UK. Possible problems in establishing use of an aid are discussed; these include inadequate training of children and their communication partners. Suggestions for future improvements of communication-aids services are explored.
Adolescent↗
Transtelephonic interrogation of the implantable cardioverter defibrillator.
Third generation implantable cardioverter defibrillators (ICDs) have extensive memory capability to store data about the patient's arrhythmias and the effect of therapies delivered by the ICD. However, this data has so far been accessible only when the patient attends the pacing clinic. Two Medtronic 9421 PCD TeletraceR transmitters have been used to interrogate Medtronic 7216A and 7217B PCD S at distances of up to 300 miles from our hospital and transmit the data to a 9420 PCD TeletraceR receiver. Successful transmission of data has been obtained on 50 occasions with 100% data concordance with repeat transmission. The system can reduce the number of unscheduled clinic visits, reduce delay in making a diagnosis following unexpected delivery of a shock therapy, and reassure patients about to be discharged following ICD implantation. The benefits are magnified where patients reside far away from the implanting center.
Electric Countershock↗
What is the contribution of occupational environmental factors to the occurrence of scleroderma in men?
An occupational analysis of 56 men with scleroderma in the United Kingdom showed no evidence that silica exposure was implicated in the onset of the disease, in contrast with older published reports suggesting that such exposure explained an important proportion of the occurrence of the disease in men. Of the major occupational exposures suggested from case reports, only organic solvents were reported to any extent in this series. No significant increase in exposure to organic solvents was noted, however, in a case control analysis.
Case-Control Studies↗
The possibility of school milk as a vehicle for fluoride: epidemiological, organisational and legal considerations.
The aim of this study was to investigate the epidemiological, organisational and legal considerations of using school milk as a vehicle for fluoride. The background to the work was the need to develop alternative methods of fluoride supplementation for high risk groups living in areas where water fluoridation is unlikely. St Helens in Merseyside was chosen as the study area, where 23 per cent of 4-year-old children were identified as having a high caries experience (dmft > or = 4). It was found that 65 per cent of 3 and 4-year-old children attend local authority educational facilities, where milk is provided on a daily basis for children aged 2 to 7 years. This group included 62 per cent of the 4-year-old group with high caries experience. The legal aspects of adding fluoride to milk were found to be complex but it was concluded that there may be considerable potential for using school milk as a vehicle for fluoride, and a large-scale study is now planned.
Animals↗
re: "Problems ascertaining friend controls in a case-control study of lung cancer".
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Case-Control Studies↗
A promoter trap in embryonic stem (ES) cells selects for integration of DNA into CpG islands.
An analysis of several G418-resistant ES cell lines produced by electroporation of a promoterless neo gene (NASTI), shows an enrichment for integrations within, or adjacent to, CpG islands. A detailed analysis of two of the cell lines reveals short regions of homology between the genomic target DNA and the construct ends, and that recombination may be mediated by DNA Topoisomerase I. The DNA flanking the insert detects transcription of endogenous genes, and in one cell line divergent transcripts are detected. This use of ES cells should provide an effective and efficient means of creating insertional mutations in mice.
Animals↗
Early adaptations in gas exchange, cardiac function and haematology to prolonged exercise training in man.
In order to determine the effect of short-term training on central adaptations, gas exchange and cardiac function were measured during a prolonged submaximal exercise challenge prior to and following 10-12 consecutive days of exercise. In addition, vascular volumes and selected haematological properties were also examined. The subjects, healthy males between the ages of 19 and 30 years of age, cycled for 2 h per day at approximately 59% of pre-training peak oxygen consumption (VO2) i.e., maximal oxygen consumption (VO2max). Following the training, VO2max (l.min-1) increased (P less than 0.05) by 4.3% (3.94, 0.11 vs 4.11, 0.11; mean, SE) whereas maximal exercise ventilation (VE,max) and maximal heart rate (fc,max) were unchanged. During submaximal exercise, VO2 was unaltered by the training whereas carbon dioxide production (VE) and respiratory exchange ratio were all reduced (P less than 0.05). The altered activity pattern failed to elicit adaptations in either submaximal exercise cardiac output or arteriovenous O2 difference. fc was reduced (P less than 0.05). Plasma volume (PV) as measured by 125I human serum albumin increased by 365 ml or 11.8%, while red cell volume (RCV) as measured by 51chromium-labelled red blood cells (RBC) was unaltered. The increase in PV was accompanied by reductions (P less than 0.05) in haematocrit, haemoglobin concentration (g.100 ml-1), and RBCs (10(6) mm-3). Collectively these changes suggest only minimal adaptations in maximal oxygen transport during the early period of prolonged exercise training. However, as evidenced by the changes during submaximal exercise, both the ventilatory and the cardiodynamic response were altered.(ABSTRACT TRUNCATED AT 250 WORDS)
Adaptation, Physiological↗