Transcript initiation, polyadenylation, and functional promoter mapping for the dihydrofolate reductase-thymidylate synthase gene of Toxoplasma gondii

The fused dihydrofolate reductase/thymidylate synthase gene of Toxoplasma gondii contains ten exons spanning approximately 8 kb of genomic DNA. We have examined the ends of DHFR-TS transcripts within this gene, and find a complex pattern including two discrete 5' termini and multiple polyadenylation sites. No TATAA box or other classical promoter motif is evident in 1.4 kb of genomic DNA upstream of the coding region, but transcript mapping by RNase protection and primer extension reveals two prominent 5' ends at positions -369 and -341 nt relative to the ATG initiation codon. Upstream genomic sequences include GC-rich regions and the (opposite strand) WGAGACG motif previously identified in other T. gondii promoters. Mutagenesis of recombinant reporter plasmids demonstrates that this region is essential for efficient transgene expression. Sequencing the 3' ends from multiple independent mRNA clones demonstrates numerous polyadenylation sites, distributed over >650 nt of genomic sequence beginning approximately 250 nt downstream of the stop codon. Within this region, certain sites seem to be preferred: 14 different positions were found among the 32 polyadenylated transcripts examined, but approximately 40% of the transcripts map to two loci. The 3' noncoding region is rich in A and T nucleotides, and contains an imperfect 50 nt direct repeat, but no obvious poly(A) addition signal was identified.

The PEP respiratory monitor: a validation study

The search for a reliable and accurate respiratory rate monitor for use in non-intubated patients has proved to be a long and fruitless one. A new device fulfilling the criteria for such a monitor has recently been described. The pyroelectric polymer (PEP) device is safe, non-invasive, and cheap. In this study the PEP device, transthoracic impedance, and standard observer counting were all compared with the existing gold standard of capnography in 12 healthy adult volunteers. Using a standard statistical technique it was shown that the PEP device performed as well as a capnograph and was more accurate than the other currently available methods of monitoring respiratory rate.

Placement of electrodes for defibrillation--a review of the evidence

Defibrillation is the only reliable treatment for ventricular fibrillation. Its success depends on the passage of an adequate current through the chest rather than on the administration of a preset energy. The final determinant of both efficacy and cellular damage is myocardial current density. Therefore, the current should be evenly distributed with an average value that exceeds the defibrillation threshold throughout a critical mass of myocardium but does not cause further local dysfunction. The distribution of current is altered by the relative positions of the two electrodes. European guidelines for electrode (paddle) placement during defibrillation are based on empirical studies and traditional practice. However, there is increasing evidence to suggest that bi-axillary electrode placement may be superior to traditional antero-apical and antero-posterior positions.

The PEP transducer: a new way of measuring respiratory rate in the non-intubated patient

OBJECTIVES

To explore the use of a pyroelectric polymer (PEP) film as a transducer for a simple respiratory rate monitor and to evaluate the transducer in a laboratory situation.

METHODS

Laboratory evaluation of a new pyroelectric transducer for measurement of respiratory rate.

RESULTS

The amplified output from the pyroelectric film produced an excellent respiratory trace when used on a normal spontaneously breathing subject. The transducer is cheap, robust, and reliable.

CONCLUSIONS

PEP films have the potential to be used as cheap and effective transducers in respiratory rate monitors for non-intubated patients. In the laboratory, they have many desirable characteristics which should now be evaluated in a clinical setting.

Use of an electric ear syringe in the emergency department

OBJECTIVES

To introduce an electric ear syringe into an emergency department and evaluate its use in the removal of foreign bodies from the external auditory canal.

METHODS

Report of the use of a new device (the Propulse electric ear syringe) in an emergency department with a retrospective audit of the management of all cases of aural foreign bodies during one year.

RESULTS

Almost 60% of the 84 patients who presented with foreign bodies in the auditory canal were children. Staff chose to treat over half of all patients with aural foreign bodies with the electric ear syringe. The overall success rates for the removal of the foreign bodies were: electric syringe, 93% in adults and 88% in children and instrumentation, 68% in adults and 50% in children.

CONCLUSIONS

Irrigation with an electric ear syringe is an effective method of removing foreign bodies from the external auditory canal. The device tested was safe, inexpensive, easy to use, and readily acceptable to both adults and children. The availability of an electric ear syringe in an emergency department can avoid the need for specialist referral and the subsequent removal of foreign bodies under general anaesthesia.

Emergency intubation of infants: does laryngoscope blade design make any difference?

OBJECTIVE

To compare intubation times and ease of use for a range of infant laryngoscope blades in the hands of accident and emergency (A&E) personnel.

METHODS

Seven different blades were compared in terms of intubation times and ease of use scores in the hands of 30 A&E senior house officers (SHOs) and nurses using a standard infant manikin.

RESULTS

There was a significant difference in intubation times between the seven blades (p < 0.001). Intubation with two blade designs (Seward and Soper) took almost twice as long as for the other blades (p < 0.05). Subjective ease of use scoring also identified the Seward and Soper blades as being the most difficult to use (p < 0.05). There were no significant differences between SHO and nurse intubation times or ease of use scoring. Successful intubation was achieved within 30 seconds in 90% of attempts. All but two of the subjects used an incorrect levering technique for intubation despite all having previously received training in infant intubation.

CONCLUSIONS

No current standard exists regarding the utilisation of infant laryngoscope blades in the A&E department. The first line blade available should be a C shaped blade (Miller, Oxford, Robert-shaw, or Wisconsin). Other blade designs should be kept for use only by more experienced personnel or in difficult intubation situations. Intubation training must focus on correct technique and regular assessment is essential.

Relation between Glasgow coma score and cough reflex

How unconscious does a patient need to be, to be intubated without drugs? In 76 comatose patients (Glasgow coma score [GCS] < or = 8) who were treated consecutively in an emergency department, the integrity of the cough reflex was not related to GCS. All comatose patients must be treated as if their airway is compromised but even at the lowest coma scores, there are many patients whose airway reflexes are sufficiently intact to make procedures such as endotracheal intubation difficult and dangerous without drugs. The state of the airway should be assessed independently of conscious level.

The first aid management of epistaxis by accident and emergency department staff

Most nose bleeds can be controlled by compressing the ala nasi, thus applying direct pressure over Little's area. The ability to demonstrate the correct position for this manoeuvre was assessed in 115 members of the staff of the accident and emergency (A&E) department of a major teaching hospital. Overall, the correct response rate was only 33% and even trained medical and nursing staff achieved less than a 50% success rate. Increased awareness of this simple and effective technique is recommended.

The Management of Dental Problems Presenting to an Accident and Emergency Department

Patients with dental diagnoses, not necessarily traumatic, often present to accident and emergency departments and general medical practitioners. Few doctors have received much, if any, education in the management of these patients. A 6 month prospective study revealed 107 patients (0.3% of new attenders) attending the accident and emergency department of Glasgow Royal Infirmary. Only 19 of these had suffered trauma. Medical staff in the department were only rarely able to make any diagnosis, and management of these patients took place on an empirical, symptomatic basis. Management could be improved by better education of medical students and doctors. Use of an algorithm may be appropriate.

The introduction of automatic blood pressure monitoring to an accident & emergency resuscitation room

Machines for automatic non-invasive blood pressure (BP) monitoring are increasingly available in British accident and emergency departments. Our department recently acquired two machines with this capability for use in the resuscitation room. This provided us with an opportunity to compare the speed and frequency of automatic BP recording with the previously used manual method. We found no significant difference in either the median time to the first recording of BP or in the median number of documented recordings in the first hour. However, the overall frequency of BP recording did show a statistically significant increase. We conclude that automation alone does not improve standard practice in this area greatly.

The Adequacy of Cervical Spine Radiographs in the Accident and Emergency Department

One hundred and twenty radiographs of the cervical spine were performed at the request of the Accident and Emergency (A & E) department over a 6 week period. These consecutive films were reviewed for adequacy of anatomical demonstration of the complete cervical spine. The initial series of three films presented to the A & E staff achieved this objective in only 55% of cases overall, although further radiographic examinations requested before the patient left the department raised this figure to 75% for the lateral view and to 70% for the combined anteroposterior (AP) views. From the data it can be predicted that if every patient whose first 3 films were inadequate had received further investigation, the cervical spine would have been well visualized on approximately 90% of radiographs in each plane. The availability of radiologists for advice and their involvement with senior A & E staff in teaching are important factors in improving this situation.

Low density lipoprotein composition and oxidizability in coronary disease — apparent favourable effect of beta blockers

The oxidative modification of LDL in vivo may have an important role in atherogenesis. To determine whether LDL fatty acid, anti-oxidant composition and sensitivity to oxidation in vitro is different in subjects with established atherosclerosis we compared 20 men with angiogram proven coronary disease with 25 controls without clinical evidence of arterial disease. LDL-cholesterol, total triglycerides and LDL fatty acid composition did not differ significantly between the groups. LDL oxidation lag time and oxidation rate in coronary patients (132 min, 0.02 absorbance units/min) and controls (140, 0.017) were not significantly different. However coronary disease subjects taking beta-blockers had evidence for reduced LDL oxidizability (lag time 148 +/- 7 min; oxidation rate 0.017 +/- 0.002 abs units/min) compared with those not on beta-blockers (lag time 114 +/- 7 min, rate 0.025 +/- 0.003, P < 0.005). LDL beta-carotene was significantly lower in coronary patients (0.92 mumol/mmol LDL cholesterol; controls 1.58; P = 0.001). LDL alpha-tocopherol appeared lower in coronary patients (2.8 mumol/mmol LDL cholesterol; controls 3.3; P = 0.056) and was significantly lower in smokers (2.56; non-smokers 3.24; P = 0.04). LDL oxidation rate was negatively correlated with LDL alpha-tocopherol (r = -0.51, P = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Intracardiac therapy following emergency thoracotomy in the accident and emergency department: an experimental model

For a select group of patients with penetrating chest trauma, immediate thoracotomy in the accident and emergency department offers the only chance of survival. Foley catheters have been used to achieve haemostasis in cardiac wounds but are not widely used for intracardiac fluid and drug administration during resuscitation. In an anatomical model designed to assess this procedure an average flow rate of 275 ml min-1 was achieved. The equipment required is readily available and easily assembled.