Biomedical subjects

A P Reid

Publications and source records attributed to A P Reid.

At least 19 recordsLinked to original sources

PubMed2001

Identifying the more patent nostril before nasotracheal intubation.

We have studied the reliability of two simple pre-induction tests used to select the more patent nostril for nasotracheal intubation by comparing their results with those obtained from fibreoptic examination of the nostrils, in 75 maxillo-facial patients requiring nasotracheal intubation under general anaesthesia, who had no history of nasal obstruction. The tests comprised (1) estimation of the rate of airflow through each nostril during expiration by palpating the passage of air when the contralateral nostril was occluded, and (2) asking for the patient's assessment of airflow through the nostrils, following the administration of a vasoconstrictor. After each test, noses were classified as left or right nostril clearer or nostrils equally clear. After the induction of general anaesthesia, bilateral nasendoscopies were performed and videotape recordings of these were later analysed by an otolaryngologist who had no knowledge of the test results. Intranasal abnormalities were identified and noses were again classified as left or right nostril clearer or nostrils equally clear. There was no significant difference between the overall diagnostic success rates of the two tests (44% and 47%, respectively). In patients with intranasal abnormalities, the numbers of correct diagnoses made by the two tests were not significantly different and were also not significantly different from the number of correct selections made if only the right nostril or only the left nostril had been used for the intubation. In view of the relatively high diagnostic failure rates, anaesthetists should not rely on the two tests investigated when selecting the best nostril for nasotracheal intubation.

Adolescent↗

PubMed2001

Redescription of Steinernema longicaudum Shen & Wang (Nematoda: Steinernematidae); geographic distribution and phenotypic variation between allopatric populations.

Steinernema longicaudum Shen & Wang is redescribed based on a comparative morphological study of specimens from the type isolate from China, and two other isolates recovered from Korea and the USA. For the first and second generation female, the location of the vulva, shape of the vulval lips, and shape and length of the tail were newly observed diagnostic characters. A more detailed description of the morphology of the male spicules and gubernaculum, and the arrangement of the genital papillae is included. A description, based on scanning electron microscopy observations, of the lateral field pattern of the third-stage infective juveniles is also provided. Additionally, restriction fragment length polymorphism profiles based on the internal transcribed spacer region, and cross-breeding tests supplement the description of this species.

Animals↗

PubMed2000

Reduction of pentylenetetrazole-induced seizure activity in awake rats by seizure-triggered trigeminal nerve stimulation.

Stimulation of the vagus nerve has become an effective method for desynchronizing the highly coherent neural activity typically associated with epileptic seizures. This technique has been used in several animal models of seizures as well as in humans suffering from epilepsy. However, application of this technique has been limited to unilateral stimulation of the vagus nerve, typically delivered according to a fixed duty cycle, independently of whether ongoing seizure activity is present. Here, we report that stimulation of another cranial nerve, the trigeminal nerve, can also cause cortical and thalamic desynchronization, resulting in a reduction of seizure activity in awake rats. Furthermore, we demonstrate that providing this stimulation only when seizure activity begins results in more effective and safer seizure reduction per second of stimulation than with previous methods. Seizure activity induced by intraperitoneal injection of pentylenetetrazole was recorded from microwire electrodes in the thalamus and cortex of awake rats while the infraorbital branch of the trigeminal nerve was stimulated via a chronically implanted nerve cuff electrode. Continuous unilateral stimulation of the trigeminal nerve reduced electrographic seizure activity by up to 78%, and bilateral trigeminal stimulation was even more effective. Using a device that automatically detects seizure activity in real time on the basis of multichannel field potential signals, we demonstrated that seizure-triggered stimulation was more effective than the stimulation protocol involving a fixed duty cycle, in terms of the percent seizure reduction per second of stimulation. In contrast to vagus nerve stimulation studies, no substantial cardiovascular side effects were observed by unilateral or bilateral stimulation of the trigeminal nerve. These findings suggest that trigeminal nerve stimulation is safe in awake rats and should be evaluated as a therapy for human seizures. Furthermore, the results demonstrate that seizure-triggered trigeminal nerve stimulation is technically feasible and could be further developed, in conjunction with real-time seizure-predicting paradigms, to prevent seizures and reduce exposure to nerve stimulation.

Animals↗

PubMed2000

Occurrence and distribution of the entomopathogenic nematodes Steinernema spp. and Heterorhabditis indica in Indonesia.

Soil samples from 79 sites on five islands of Indonesia were baited with insects for the recovery of entomopathogenic nematodes. Heterorhabditis and Steinernema were equally prevalent, and were recovered from 11.7% of samples representing 20.3% of sites sampled. Both genera were recovered from coastal sites only. Entomopathogenic nematodes were more prevalent on the Moluccan islands of Ambon and Seram than on Java or Bali. They were not detected on Sulawesi, where non-coastal sites only were sampled. RFLP analysis was used in the identification of nematode isolates. Heterorhabditis indica was the only heterorhabditid identified. Two RFLP types of Steinernema were identified.

Animals↗

PubMed2000

Genomic variability within laboratory and wild isolates of the trichostrongyle mouse nematode Heligmosomoides polygyrus.

PCR-RFLP techniques have been used to characterize wild and laboratory isolates of the trichostrongyle nematode Heligmosomoides polygyrus from the wood mouse Apodemus sylvaticus and the laboratory mouse Mus musculus respectively. Both isolates can be distinguished by eight endonuclease digestions of the ITS region of the rDNA repeat namely, Alu I, Dde I, Hpa II, Hae III, Hinf I, Hha I, Pvu II and Sal I. In two of the digests, Hinf I and Rsa I, a minor polymorphism was observed in the wild isolate of H. polygyrus which has been cultured in laboratory-bred A. sylvaticus for several generations when compared with H. p. polygyrus from wild A. sylvaticus. A minor polymorphism was also identified in further wild isolates of H. polygyrus collected from A. sylvaticus in a field site in Egham, Surrey. However no evidence of polymorphism was observed in the laboratory isolate of H. polygyrus from the CD1 strain of M. musculus and the laboratory-bred A. sylvaticus. Reasons for this are discussed and further studies on the population genetics of H. polygyrus are suggested.

Animals↗

PubMed2000

Immune responses of the argasid tick Ornithodoros moubata moubata induced by infection with the filarial worm Acanthocheilonema viteae.

Investigations were undertaken to determine whether the tick Ornithodoros moubata moubata mounted a detectable immune response to primary and secondary infections with Acanthocheilonema viteae. Uninfected control tick survival rate was 70%, but only 45% in the primary infection group. Post-secondary infection survival rate (82%) was comparable to controls, indicating that these selected ticks had some protective advantage. Mean A. viteae infective larvae recovery from ticks with secondary infections was 31.4% lower than expected, suggesting the development of immunity. SDS-PAGE of haemolymph for proteins induced post-primary infection yielded a stronger signal at 45 kDa than controls, which was further elevated post-secondary infection. Proteins at 48, 22 and 16 to 18 kDa were detected in haemolymph from infected ticks but not seen from controls. The direct effect of haemolymph on microfilarial viability was examined using a novel in vitro assay; in these preliminary trials no differences were observed in parasite viability when exposed to haemolymph from infected or uninfected groups of ticks.

Animals↗

PubMed1999

Novel application of PhastSystem polyacrylamide gel electrophoresis using restriction fragment length polymorphism--internal transcribed spacer patterns of individuals for molecular identification of entomopathogenic nematodes.

différences! [editorial] [editorial]onomic way of identifying and assigning nematodes to taxons, which had already been determined either by comparative sequence analysis of nuclear rDNA internal transcribed spacer (ITS) region or by other methods of molecular or conventional taxonomy, is provided. Molecular identification of entomopathogenic nematodes (EPN) can be upgraded by basing it on PhastSystem polyacrylamide gel electrophoresis (PAGE) analysis of restriction fragment length polymorphism (RFLP) patterns of polymerase chain reaction (PCR)-amplified DNA derived from single nematodes of Steinernema or Heterorhabditis spp. Although analysis from single worms has previously been made on agarose gel, the resolution on PhastSystem PAGE gel is much higher. The DNA sequences selected for analysis were those constituting the internal transcribed spacer region between the 18S and 26S rDNA genes within the rRNA operon. RFLP analysis was carried out by gel electrophoresis on the PhastSystem (Pharmacia) as detailed elsewhere (Triga et al., Electrophoresis 1999, 20, 1272-1277. The downscaling from conventional agarose to PhastSystem gels resulted in pattern of DNA fragments differing from those obtained with agarose gel electrophoresis under conventional conditions by increasing the number of detected fragments. The approach supported previous species identifications and was able to identify several unclassified isolates, such as those from Hungary and Ireland, and provides a method for identification of previously unclassified strains. We confirmed that Heterorhabditis "Irish Type", represented by two strains of different geographical origin, comprise a species different from H. megidis. We also confirmed that strain IS5 belongs to the species H. indicus rather than to H. bacteriophora, as had been suggested previously.

Animals↗

PubMed1999

Asymptomatic intranasal abnormalities influencing the choice of nostril for nasotracheal intubation.

We have studied the prevalence of intranasal abnormalities that may influence the choice of nostril for intubation, using the fibreoptic laryngoscope, in 60 oral surgery patients presenting for nasotracheal intubation under general anaesthesia, who had no symptoms or signs of nasal obstruction. Videotape recordings were made during each nasendoscopy and later analysed by an anaesthetist and an otolaryngologist. A total of 68% of patients had intranasal abnormalities (10% bilateral and 58% unilateral) which resulted in one nostril being more patent than the other and therefore considered more suitable for intubation. The most common abnormality was deviated nasal septum which occurred in 57% of the study group; 22% were minor deviations, 13% were major deviations and 22% were impactions. Other abnormalities were simple spurs, unilateral polyp and hypertrophy of the inferior turbinate. In view of the relatively high incidence of intranasal pathology revealed on endoscopic examination, anaesthetists should consider using the fibreoptic laryngoscope to select the best nostril when performing nasotracheal intubation.

Adolescent↗

PubMed1996

Learning fibreoptic skills in ear, nose and throat clinics.

We have compared the progress of anaesthetists taught fibreoptic techniques on awake patients in ear, nose and throat clinics with that of anaesthetists taught by traditional methods. Twelve anaesthetists participated in the study and were randomly allocated to the ear, nose and throat group or to the traditional training group. Each individual in the ear, nose and throat group attended the outpatient clinic and performed ten nasendoscopies on awake patient, whose upper airway had been anaesthetised with cocaine, under the supervision of an ear, nose and throat surgeon. Each individual in the traditional roup performed ten nasendoscopies on anaesthetised oral surgery inpatients under the supervision of an anaesthetist. To assess the effectiveness of the two training methods, each anaesthetist in each group then attempted ten fibreoptic nasotracheal intubations on anaesthetised oral surgery patients. There was no significant difference between either the success rates or mean successful tracheoscopy times between the two groups. Nasendoscopy training in the ear, nose and throat clinic appears to be good way of learning fibreoptic skills, which can then be readily applied to fibreoptic tracheal intubation in anaesthetic practice.

Adult↗

PubMed1995

Prevalence and habitat specificity of steinernematid and heterorhabditid nematodes isolated during soil surveys of the UK and the Netherlands.

Entomopathogenic nematodes were isolated from soil samples collected during three separate surveys, two in the United Kingdom and one in the Netherlands. The nematodes were identified by their restriction fragment length polymorphisms on hybridization of Southern blots with a ribosomal DNA repeat unit clone. A total of eight steinernematid species/RFLP types and two heterorhabditids were isolated. The distributions of the majority of these species/RFLP types were significantly different between the three surveys and some of the species displayed a close association with certain habitat types.

Animals↗

PubMed1994

Genomic variability within laboratory and wild subspecies of Heligmosomoides polygyrus.

Genomic DNA extracted from laboratory and wild subspecies of the trichostrongyle nematode Heligmosomoides polygyrus were compared using RFLP and DNA/DNA hybridization techniques. Eight restriction endonuclease digests of the genomic DNA of the two subspecies were hybridized with heterologous ribosomal DNA probes and the total radio-isotope labelled DNA of the laboratory subspecies. DNA hybridization of the two subspecies of H. polygyrus yielded different banding patterns when probed with the rDNA clones in Pvu II digests and when total genomic DNA was used as the probe in Hind III and Pvu II digests. The remaining hybridization profiles of both subspecies were identical.

Animals↗

PubMed1994

Unilateral nasal obstruction: an unusual presentation of a complication of nasotracheal intubation.

Partial avulsion of the middle turbinate is an unusual complication of nasotracheal intubation while minor nasal mucosal trauma is not uncommon. Nasal turbinate avulsion often presents with persistent epistaxis but in the case reported, unilateral nasal obstruction with minimal epistaxis was the presenting feature. Unilateral nasal obstruction following nasotracheal intubation should raise suspicion of significant disruption of the intranasal architecture.

Adult↗

PubMed1994

Patient compliance with short-term topical aural antibiotic therapy.

Little is known about patient compliance with topical aural antibiotic regimens. The compliance of 50 patients with unilateral otitis externa attending an otolaryngology clinic was studied by comparing the weight of dispensed topical ear preparations before and after completion of a 7-day-course of treatment. A standard was obtained from controlled administration of the preparation under laboratory conditions and the performance of different delivery systems evaluated. Thirty-seven patients re-attended for review with their medication. A total of 34 of 50 patients entering the study (70%) satisfied conventional criteria for compliance. However, over-use of preparations was common and stricter criteria are proposed and applied. Compliance was significantly increased when someone other than the patient administered the preparation.

Administration, Topical↗

PubMed1993

The effect of aluminium coating on elemental signals in X-ray microanalysis.

It has been determined that, in the normal range of aluminium coating thicknesses used to remove charge from non-conducting specimens in the electron microscope, no detectable influence on the elemental signals obtained in X-ray microanalysis is observed. This is in contrast to a previous report (Hopkins et al., J. Electron Microsc. Tech., 18:176-182, 1991) of a reduction in elemental signal with increasing aluminium coating thickness. An explanation of errors in the previous interpretation is provided.

Aluminum↗

PubMed1992

Preparation of aqueous standards for low temperature X-ray microanalysis.

A technique, using Nuclepore polycarbonate membrane filters as a containing medium for very small volumes of ionic standard solutions, to produce homogeneous ice standards is described. The standards are suitable for use in a scanning electron microscope. The relationship between elemental X-ray counts and ionic concentration is found to be linear. The method is rapid and simple. Minimum detectable concentrations are given.

Electron Probe Microanalysis↗

PubMed1991

Distribution of ear drops in normal ears.

Ear drops are prescribed widely with little thought for the distribution inside the ear canal. This study compares the distribution of water and oil based drops. The results indicate that, under the test conditions, the penetration of ear drops is extremely variable. Water provided the greatest overall coverage, while the most viscous drops fared worst. It is suggested that in diseased ears even poorer penetration may result, which may explain the lack of response in some circumstances.

Adult↗

PubMed1991

Staging carcinoma: its value in cancer of the larynx.

Three thousand four hundred and forty-five cases of cancer of the larynx were examined and 3,235 assigned to their TNM group. While good correlation with prognosis could be seen, the value of the detailed subsite (as opposed to the main laryngeal regions) was limited to defining T1a and T1b and aiding that of T2. T status gives some indication of prognosis, but the N status is of almost overriding importance.

Female↗

PubMed1991

Distribution of ear drops using a non-aerosol spray delivery system.

The distribution of ear drops in normal ears is variable. A new product Otomize (Stafford-Miller) containing dexamethasone and neomycin has a non-aerosol spray mist delivery system. This has been applied to normal ears and found to be superior in its distribution to generally available ear drops previously assessed.

Administration, Topical↗