Training in basic and advanced life support in UK medical schools: questionnaire survey.
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Advanced Cardiac Life Support↗
Biomedical subjects
J P Nolan
Publications and source records attributed to J P Nolan.
A dynamic inline sample thermoregulation unit for flow cytometry.
BACKGROUND: Flow cytometry is a valuable tool for the study of cellular and molecular interactions. We sought to develop instrumentation that would allow accurate and precise inline dynamic temperature control of flow cytometry samples in order to expand the analytical capabilities of flow cytometry. METHODS: Using a temperature controller, DC power supply, and a Peltier module, we designed a temperature control circuit that regulates the temperature of a heat transfer block. The heat transfer block surrounds the sample line to efficiently heat and cool the sample. We attached DNA oligomers to microspheres and observed the denaturation of fluorescently labeled complementary oligomers to verify that the sample was achieving the desired temperature. RESULTS: The inline thermoregulation unit can ramp between 30 and 95 degrees C (>2 degrees C per second) within 30 s repeatedly. The accuracy of the instrument was verified by comparing the observed melting temperatures of the oligomer sets to the predicted values. These values varied within 6% of the predicted and were reproducible over a variety of conditions. CONCLUSIONS: The apparatus we constructed accurately and dynamically controls the sample temperature of inline samples. Flow cytometers equipped with our inline thermoregulation unit will be able to conveniently use temperature as a robust experimental parameter.
Base Sequence↗
The respiratory system during resuscitation: a review of the history, risk of infection during assisted ventilation, respiratory mechanics, and ventilation strategies for patients with an unprotected airway.
The fear of acquiring infectious diseases has resulted in reluctance among healthcare professionals and the lay public to perform mouth-to-mouth ventilation. However, the benefit of basic life support for a patient in cardiopulmonary or respiratory arrest greatly outweighs the risk for secondary infection in the rescuer or the patient. The distribution of ventilation volume between lungs and stomach in the unprotected airway depends on patient variables such as lower oesophageal sphincter pressure, airway resistance and respiratory system compliance, and the technique applied while performing basic or advanced airway support, such as head position, inflation flow rate and time, which determine upper airway pressure. The combination of these variables determines gas distribution between the lungs and the oesophagus and subsequently, the stomach. During bag-valve-mask ventilation of patients in respiratory or cardiac arrest with oxygen supplementation (> or = 40% oxygen), a tidal volume of 6-7 ml kg(-1) ( approximately 500 ml) given over 1-2 s until the chest rises is recommended. For bag-valve-mask ventilation with room-air, a tidal volume of 10 ml kg(-1) (700-1000 ml) in an adult given over 2 s until the chest rises clearly is recommended. During mouth-to-mouth ventilation, a breath over 2 s sufficient to make the chest rise clearly (a tidal volume of approximately 10 ml kg(-1) approximately 700-1000 ml in an adult) is recommended.
History, Ancient↗
An evaluation of the Airway Management Device.
We have evaluated the Airway Management Device (AMD) in 105 anaesthetised patients. We were successful in establishing a clear airway on the first attempt on 69 occasions and unable to establish a patent airway at all in 10 patients. Airway obstruction requiring removal of the device occurred during maintenance of anaesthesia in a further two cases and during emergence in three. Loss of the airway during anaesthesia occurred in eight of 95 patients and could be reversed by manipulation of the airway in six cases. Overall, a mean of 0.56 manipulations per patient were required to establish an airway and a further 0.42 per patient were required during maintenance of anaesthesia. In the 95 patients in whom an airway was established, assisted ventilation was satisfactory in 93, with a leak pressure above 20 cmH2O in 65. Intracuff pressure was measured in 12 cases and was above 100 cmH2O in eight. Minor complications occurred in 12 patients. Blood was visible on removal of the device in six cases.
Adolescent↗
Rescue breathing and bag-mask ventilation.
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Airway Obstruction↗
Cardiovascular and systemic responses to inhaled pollutants in rodents: effects of ozone and particulate matter.
Striking similarities have been observed in a number of extrapulmonary responses of rodents to seemingly disparate ambient pollutants. These responses are often characterized by primary decreases in important indices of cardiac and thermoregulatory function, along with secondary decreases in associated parameters. For example, when rats are exposed to typical experimental concentrations of ozone (O(3), they demonstrate robust and consistent decreases in heart rate (HR) ranging from 50 to 100 beats per minute, whereas core temperature (T(co) often falls 1.5-2.5 degrees C. Other related indices, such as metabolism, minute ventilation, blood pressure, and cardiac output, appear to exhibit similar deficits. The magnitudes of the observed decreases may be modulated by changes in experimental conditions and appear to vary inversely with both ambient temperature and body mass. More recent studies in which both healthy and compromised rats were exposed to either particulate matter or its specific components yielded similar results. The agents studied included representative examples of ambient, combustion, and natural source particles, along with individual or combined exposures to their primary metallic constituents. In addition to the substantial decreases in HR and T(co), similar to those seen with the O(3)-exposed rats, these animals also displayed numerous adverse changes in electrocardiographic waveforms and cardiac rhythm, frequently resulting in fatal outcomes. Although there is only limited experimental evidence that addresses the underlying mechanisms of these responses, there is some indication that they may be related to stimulation of pulmonary irritant receptors and that they may be at least partially mediated via the parasympathetic nervous system.
Air Pollutants↗
Development of a mechanism-based, DNA staining protocol using SYTOX orange nucleic acid stain and DNA fragment sizing flow cytometry.
Accurate measurement of single DNA fragments by DNA fragment sizing flow cytometry (FSFC) depends upon precise, stoichiometric DNA staining by the intercalating dye molecules. In this study, we determined the binding characteristics of a commercially available 532 nm wavelength-excitable dye and used this information to develop a universal DNA staining protocol for DNA FSFC using a compact frequency-doubled Nd:YAG laser excitation source. Among twelve 532 nm wavelength-excitable nucleic acid staining dyes tested, SYTOX Orange stain showed the highest fluorescence intensity along with a large fluorescence enhancement upon binding to double-stranded DNA ( approximately 450-fold). Furthermore, using SYTOX Orange stain, accurate fragment-size-distribution histograms were consistently obtained without regard to the staining dye to base pair (dye/bp) ratio. A model describing two binding modes, intercalation (primary, yielding fluorescence) and external binding (secondary, involving fluorescence quenching), was proposed to interpret the performance of the dyes under different dye/bp ratios. The secondary equilibrium dissociation constant was found to be the most critical parameter in determining the sensitivity of each fluorophore to the staining dye/bp ratio. The measurements of both equilibrium dissociation constants provided us with a theoretical framework for developing a universal protocol which was successfully demonstrated over a wide range of DNA concentrations on a compact flow cytometer equipped with a frequency-doubled, diode-pumped, solid-state Nd:YAG laser for rapid and sensitive DNA fragment sizing.
Bacteriophage lambda↗
Flow cytometry-based minisequencing: a new platform for high-throughput single-nucleotide polymorphism scoring.
Single-nucleotide polymorphisms (SNPs) are the most abundant type of human genetic variation. These variable sites are present at high density in the genome, making them powerful tools for mapping and diagnosing disease-related alleles. We have developed a sensitive and rapid flow cytometry-based assay for the multiplexed analysis of SNPs based on polymerase-mediated primer extension, or minisequencing, using microspheres as solid supports. The new method involves subnanomolar concentrations of sample in small volumes ( approximately 10 microl) which can be analyzed at rates of one sample per minute or faster, without a wash step. Further, genomic analysis using multiplexing microsphere arrays (GAMMArrays), enables the simultaneous analysis of dozens, and potentially hundreds of SNPs per sample. We have tested the new method by genotyping the Glu69 variant from the HLA DPB1 locus, a SNP associated with chronic beryllium disease, as well as HLA DPA1 alleles using the multiplexed method. The results demonstrate the sensitivity and accuracy of flow cytometry-based minisequencing, a powerful new tool for genome- and global-scale SNP analysis.
Base Sequence↗
Single-molecule detection with total internal reflection excitation: comparing signal-to-background and total signals in different geometries.
Excitation of fluorescence with total internal reflection (TIR) excitation yields very low background scattered light and good signal-to-background contrast. The background and its associated noise can be made low enough to detect single fluorescent molecules under ambient conditions. In this paper, different TIR geometries were compared for excitation and detection of single rhodamine 6G (R6G) molecules at air-silica interfaces and single B-phycoerythrin proteins at water-silica interfaces. Through-objective, objective-coverslip, and prism-based TIR geometries were investigated. The signal-to-background ratio (SBR) and the number of photons detected before photobleaching (Nb) were optimum in different geometries. The greatest image contrast was obtained when using prism-TIR (SBR = 11.5), but the largest number of detected signal photoelectrons was obtained by using through-objective TIR for R6G-air-silica ( = 10(4)). The results were discussed in terms of the TIR field enhancements and the modified dipole emission pattern near a dielectric interface. The SBR and total detected photons are important parameters for designing photon-limited experiments.
Fluorescent Dyes↗
What are the requirements for medical cover at motor racing circuits?
Motor racing is perceived as a dangerous sport but few data are available on the incidence and nature of injuries sustained. The medical service requirement at one regional motor racing circuit was assessed by determining the incidence of injuries, the medical interventions required and the need for hospital referral and admission over a 5-year period. Five hundred and twenty-one patients, including support staff and spectators, attended the medical centre, of whom 14% were referred to hospital and 4% required admission. Each competitor had a 4% chance of requiring on-circuit medical attention, 0.6% chance of hospital referral and 0.17% chance of admission per race. Most major accidents involved more than two drivers. Twenty sustained major trauma including five pelvic fractures and two intraabdominal haemorrhages. Emergency intervention included intubation and ventilation in five. There were three deaths from a total of 9000 competitors (mortality rate 0.033%). This study shows that despite the nature of the sport, the mortality rate remains low with prompt skilled medical intervention. Medical personnel should include those competent in dealing with minor medical complaints as well as those with advanced airway management and resuscitation skills. Although national motor sport guidelines recommend a minimum of two attending doctors this would have been insufficient for multivehicle accidents.
Athletic Injuries↗
The use of cricoid pressure with the intubating laryngeal mask.
Unexpected difficulty with tracheal intubation contributes to anaesthetic morbidity and mortality. The intubating laryngeal mask is effective in facilitating blind intubation. We have evaluated the effect of cricoid pressure on the ability to insert an intubating laryngeal mask, and to pass a tracheal tube through it. Insertion and intubation through the mask were attempted in 50 patients, Mallampati grade 1-3, randomly allocated to cricoid and noncricoid pressure groups. Tracheal intubation was successful in 21 (84%) of the noncricoid group and 13 (52%) of the cricoid group (p = 0.03). Cricoid pressure may have to be released to allow correct placement and intubation through the intubating laryngeal mask.
Adult↗
A novel role in DNA metabolism for the binding of Fen1/Rad27 to PCNA and implications for genetic risk.
Fen1/Rad27 nuclease activity, which is important in DNA metabolism, is stimulated by proliferating cell nuclear antigen (PCNA) in vitro. The in vivo role of the PCNA interaction was investigated in the yeast Rad27. A nuclease-defective rad27 mutation had a dominant-negative effect that was suppressed by a mutation in the PCNA binding site, thereby demonstrating the importance of the Rad27-PCNA interaction. The PCNA-binding defect alone had little effect on mutation, recombination, and the methyl methanesulfonate (MMS) response in repair-competent cells, but it greatly amplified the MMS sensitivity of a rad51 mutant. Furthermore, the PCNA binding mutation resulted in lethality when combined with a homozygous or even a heterozygous pol3-01 mutation in the 3'-->5' exonuclease domain of DNA polymerase delta. These results suggest that phenotypically mild polymorphisms in DNA metabolic proteins can have dramatic consequences when combined.
Binding Sites↗
Partial functional deficiency of E160D flap endonuclease-1 mutant in vitro and in vivo is due to defective cleavage of DNA substrates.
To assess the roles of the active site residues Glu160 and Asp181 of human FEN-1 nuclease in binding and catalysis of the flap DNA substrate and in vivo biological processes of DNA damage and repair, five different amino acids were replaced at each site through site-directed mutagenesis of the FEN-1 gene. The mutants were then expressed in Escherichia coli and purified using a His-tag. Even though the mutants bind to the flap DNA to different degrees, most of the mutants lost flap nuclease activity with the exception of an E160D mutant. This mutant retained wild type-like binding ability, specificity, and partial catalytic activity. Detailed steady state and pre-steady state kinetic analysis revealed that the functional deficiency of this mutant was due to retardation of the endonucleolytic cleavage. When the mutant enzyme E160D was expressed in yeast, it partially complements the biological functions of the homologous yeast gene, RAD27, and reverses the hyper-temperature lethality and hypersensitivity to methyl methanesulfonate, in a manner corresponding to the in vitro activity.
Base Sequence↗
Internal medicine in the current health care environment: a need for reaffirmation.
Managed care has substantially changed the environment of health care delivery for general internists and internist-subspecialists. In the current system, one may wonder whether detailed and thoughtful workups still have a role when the direction of medical practice increasingly prizes a high volume of brief encounters. However, the very forces that drive managed care make the role of internist in the care of adults even more central. The internist's unique training and clinical approach should lead to both medically effective and cost-effective health care for adults. This type of health care will be increasingly important as the U.S. population ages and an increasing number of Americans have chronic, multisystem disease. Over the past century, internal medicine has evolved from a consultative model to a discipline that encompasses total adult care, from prevention to diagnosis and treatment of acute and chronic illness and from outpatient care in the office to inpatient care in the intensive care unit. However, the leadership role of internists in the medical care of adults is now being threatened by family medicine and by fragmentation within internal medicine itself. Managed care organizations and the general public must be shown why internists are better able than family physicians to meet the health care needs of adults. Furthermore, as the marketplace becomes more competitive, the issue of when care given by a subspecialist is superior to that given by an internist has become more prominent. The rapidly developing "hospitalist" movement also threatens the traditional role of the internist as the caregiver for adults in health and disease. Given the historic flexibility of internal medicine and the assumption that appropriate roles can be defined for family physicians, subspecialists, and hospitalists, internists will continue to play a central role in providing the best care for adults in the new world of health care delivery.
Adult↗
Effectiveness of regional trauma systems. Wrong comparisons were made.
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Hospitals, District↗
Modulation of GTPase activity of G proteins by fluid shear stress and phospholipid composition.
Mechanical forces arising from strain, pressure, and fluid shear stress are sensed by cells through an unidentified mechanoreceptor(s) coupled to intracellular signaling pathways. In vascular endothelial cells, fluid shear stress is transduced via pathway(s) involving heterotrimeric guanine nucleotide-binding proteins (G proteins) by molecular mechanisms that are unknown. In the present study, we investigated the activation of purified G proteins reconstituted into phospholipid vesicles. Vesicles containing G proteins were loaded with [gamma-32P]GTP and subjected to physiological levels of fluid shear stress in a cone-and-plate viscometer. Steady-state GTP hydrolysis was measured as an index of G protein function. Shear stress (0-30 dynes/cm2) activated G proteins in dose-dependent manner (0.48-4.6 pmol/min per microg of protein). Liposomes containing lysophosphatidylcholine (30 mol %) or treated with benzyl alcohol (40 mM), conditions that increase bilayer fluidity, exhibited 3- to 5-fold enhancement of basal GTPase activity. Conversely, incorporation of cholesterol (24 mol %) into liposomes reduced the activation of G proteins by shear. These results demonstrate the ability of the phospholipid bilayer to mediate the shear stress-induced activation of membrane-bound G proteins in the absence of protein receptors and that bilayer physical properties modulate this response.
Animals↗
A fatal complication of the Seldings technique for cannulation of the femoral vein.
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Acute Kidney Injury↗
The emergence of flow cytometry for sensitive, real-time measurements of molecular interactions.
The analysis of macromolecular interactions is an essential element of biomedical research. Flow cytometry is uniquely capable of making sensitive and quantitative measurements of molecular interactions. These measurements can be made in real time with subsecond kinetic resolution using purified biomolecules or living cells. Combined with automated sample handling, these features make flow cytometry a versatile and robust technology for the analysis of molecular interactions.
Antigens, Surface↗