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Biomedical subjects

S A O'Connor

Publications and source records attributed to S A O'Connor.

At least 19 recordsLinked to original sources
PubMed2003

VNS in patients with previous unsuccessful resective epilepsy surgery: antiepileptic and psychotropic effects.

OBJECTIVES: To assess the efficacy of vagus nerve stimulation (VNS) in patients with medically and surgically intractable complex partial seizures (CPS). PATIENTS AND METHODS: Sixteen patients with previous temporal [15] and frontal [one] resections were treated with VNS between 1994 and 1999 at King's College Hospital, London, UK. Post-operative video-electroencephalogram telemetry had shown that CPS started from the operated side in 12 patients, contralaterally in three and bilaterally independently in one. RESULTS: Three patients (18.75%) had 50% or more reduction in seizure frequency, but one showed severe worsening of epilepsy, which remitted upon VNS discontinuation. The antiepileptic effect of VNS was not different with respect to the type of operation (anterior temporal lobectomy vs amygdalohippocampectomy), the side of operation, or the side of seizure onset. We observed psychotropic effects in two patients with post-ictal psychosis, in two others with depression, and in a child with severe behavioral disorder. CONCLUSIONS: VNS may have a rather limited antiepileptic role to play in patients with persistent seizures following epilepsy surgery, but may independently possess useful antipsychotic and mood-stabilizing properties.

Adolescent↗
PubMed2001

Fibroma (myxoma) molle in a hamster (Mesocricetus auratus).

An adult female Syrian hamster (Mesocricetus auratus) presented with a large, ulcerated lesion in its right cheek pouch; this wound interfered with the animal's ability to masticate. As a result, the hamster became inappetant and lethargic and lost about 25% of its original body weight within 6 to 9 weeks of presentation. The mass was surgically excised and submitted for histopathological evaluation. Microscopically, the mass was characterized as a neoplastic process partially encapsulated with fibrous connective tissue in the submucosa. Loosely arranged bundles of spindle to stellate cells with round to oval hyperchromatic nuclei and amphophilic cytoplasm were abundant. Some cells had multiple nucleoli, and some mitotic figures were observed. Special stains were used to definitively diagnose fibroma (myxoma) molle, a rare spontaneous neoplastic lesion in the hamster.

Animals↗
PubMed1994

Compliance with prescribed drug therapy in asthma.

Morbidity and mortality from asthma in the Western world is increasing despite effective prophylactic drugs. Beta agonists are increasingly considered causal; while under-prescribing of inhaled steroids or other anti-inflammatories are accepted as causes for the problems, but the role of non-compliance with inhaled asthma therapy is rarely mentioned. Using a novel electromechanical counter MDI actuations have been recorded in three small (9-11 patients), short (2-3 weeks) studies. When aware compliance with prescribed inhaled steroids was under scrutiny, six patients were fully compliant, two took just 70% of the prescribed regimen, but two did not follow the prescribed regimen at all. When unaware of scrutiny, six out of 11 were compliant but five patients were estimated as taking less than 30-51% of the prescribed dose of inhaled steroid. When asked to monitor rescue bronchodilator usage patients consistently under-recorded. Under-use as well as under prescription of inhaled steroids and under-estimation (8) of beta 2-agonists use may be contributory factors to the present increase in asthma mortality and morbidity. These potential problems of poor compliance need larger scale studies to show how and if behaviour can be altered to improve compliance.

Adrenergic beta-Agonists↗
PubMed1994

A perioperative acuity measurement system.

An integrative acuity measurement system has been developed to increase efficiency and effectiveness of care delivery. Patients are classified into groups on the basis of nursing care required, thus facilitating both determination of actual nursing cost and accurate projection of staffing needs. It provides a universal language among perioperative departments for measuring similar outcomes.

Data Collection↗
PubMed1991

Generation and multiplication of plantlets from callus derived from Haplopappus gracilus (Nutt.) Gray and their karyotype analysis.

Unopened flower heads of Haplopappus gracilis (2n = 4) provided primary explants for callus production and subsequent induction of organized growth. Callus was initiated from small (3-5 mm in length) floral buds with benzylaminopurine (BAP) (44.4 micromoles; 10 mg/l) and naphthalene acetic acid (NAA) (0.54 micromole; 0.1 mg/l). Lowering the BAP level to 4.44 micromoles (1 mg/l) but maintaining the NAA level, gave rise to organized but highly compressed shoot growing points from an otherwise undifferentiated callus mass. Shoots selected from such cultures were maintainable and could be proliferated by growing 1-1.5-cm stem tip cuttings on Murashige and Skoog basal medium (solidified with agar) containing 0.444 micromole (0.1 mg/l) BAP and 0.054 micromole (0.01 mg/l) NAA. The stem tip multiplication rates obtainable by these means permit reliable strategies for shoot multiplication or production of rooted plantlets. Prolonged subculture and maintenance of shoots on growth regulator-free medium leads to in vitro flowering and greatly reduces rooting capacity. Karyotype analysis of chromosomes from root tip cells at metaphase and chromosome measurements show that karyologically uniform plantlets (based on chromosome number and morphology) can be obtained.

Adenine↗
PubMed1988

A double-blind study of the respiratory effects of nalbuphine hydrochloride in spontaneously breathing anesthetized patients.

Nalbuphine hydrochloride 0.2 mg/kg was compared with meperidine 0.5 mg/kg in a double-blind study in 20 patients undergoing elective inguinal hernia repair while breathing spontaneously under general anesthesia. The respiratory effects of the two drugs studied were continuously and accurately recorded with a wet wedge spirometer throughout the procedure. The acute respiratory effects of these analgesic drugs could therefore be assessed. The measurements recorded before any surgical stimulation showed that both nalbuphine and meperidine produce a similar degree of respiratory depression. These results are at variance with earlier studies that drew conclusions from measurements that were neither continuous nor accurate. Nalbuphine was found to be a satisfactory analgesic adjuvant in this anesthetic technique.

Adult↗
PubMed1987

An electronic processor for use with a whole body plethysmograph to determine specific airways conductance.

The panting manoeuvre traces produced by a whole body plethysmograph during the measurement of specific airways conductance (sGaw) are traditionally analysed by hand. Since this technique is tedious and time consuming it is prone to error, as well as suffering from considerable inter-observer variability. We describe a new inexpensive analogue electronic processor which rapidly produces readouts of sGaw and overcomes many of the problems associated with hand analysis. The system takes as its inputs the mouth flow and plethysmograph volume outputs from a pressure-corrected flow-displacement whole body plethysmograph, but it could be adapted for use with other types of plethysmograph. Since the processor is intended mainly for use during serial measurements of sGaw it does not carry out an unnecessary correction for flowmeter resistance. Using an electronic simulator of sGaw signals the output of the processor was found to be linear to better than 2% of full scale and to be insensitive to drift on the volume signal. The system has been comprehensively evaluated using signals from both normal subjects and patients. The processor output was found to agree well with the results of hand analysis, an agreement which was comparable with that obtained from computer based systems. For the normal subjects the equal value line adequately described the relationship between the processor and hand estimates of sGaw. However, for patients the slope of the best fit line was 18% less than unity but the correlation coefficient was high: 0.95. Reproducibility was found to be better than 3%.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1985

Meptazinol--a cause of respiratory depression in general anaesthesia.

The respiratory effects of meptazinol 1 mg kg-1 have been compared with those of pethidine 0.5 mg kg-1 and 1 mg kg-1 in a double-blind trial in 30 patients undergoing arthroscopic meniscectomy under general anaesthesia. Respiratory depression was seen in all treatment groups. Pethidine 1 mg kg-1 produced respiratory depression which was greater than that produced by meptazinol 1 mg kg-1. The least depressant respiratory effects were seen in the group receiving pethidine 0.5 mg kg-1. We submit that the measurement of tidal volume enhances the assessment of the respiratory effects of analgesic drugs during anaesthesia.

Adult↗
PubMed1984

Karyological observations.

Root tips prepared for metaphase chromosome analysis from seedlings germinated under microgravity on the Space Shuttle (oats and mung bean) or which were exposed to space flight as very young seedlings (sunflower) have been examined. Experimental constraints did not permit pre-fixation in space with a cytostatic agent but arrest was achieved in the first division cycle on Earth after recovery. The number of cells in division was significantly depressed in all three species. Several chromosomal abnormalities were encountered in flight material. Bridge formation was seen in sunflower, as was aneuploidy. Breakage and fracture of chromosomes was prevalent in oats. No aberrant features could be detected in the chromosomes of mung bean. These results, although preliminary, should serve to alert investigators of the need to assess carefully as many aspects of cell division in higher plants exposed to space flight conditions as possible.

Aneuploidy↗
PubMed1979

Changes in pulmonary function after naturally acquired respiratory infection in normal persons.

Changes in pulmonary function due to naturally occurring respiratory tract infection were examinated in 26 normal healthy volunteers during a period of 6 months. Forced expiratory maneuvers in each volunteer were recorded at 2-wk intervals throughout the study and daily during illness. Significant impairment of peak expiratory flow rate, forced vital capacity, forced expiratory volume in one second, and maximal mid-expiratory flow rate at 50% of the vital capacity was observed during infection, whereas changes in the maximal expiratory flow rate at 75% of vital capacity were nonsignificant. From these results, we conclude that large airways are certainly affected during uncomplicated respiratory infections in normal healthy persons and from the changes observed in FVC we suggest that more widespread involvement of the small airways may occur.

Adolescent↗