PubMed HealthSearch

Biomedical subjects

E O'Sullivan

Publications and source records attributed to E O'Sullivan.

At least 19 recordsLinked to original sources

Remembered saccades with variable delay in Parkinson's disease.

The effect of increasing delay on the metrics of remembered saccades was studied in 10 subjects with mild Parkinson's disease, none of whom was receiving treatment with L-dopa, and nine age-matched control subjects. Delays of 1 msec, 250 msec, 1000 msec, 2500 msec, and 5000 msec were used, and reflexive saccades used as a control condition. Results were analyzed for the gain of the primary saccade and the accuracy of the final eye position (FEP gain). Reflexive saccades were normal in subjects with Parkinson's disease, but remembered saccades showed marked hypometria of primary saccade gain at all delays. FEP gain was unimpaired in Parkinson's disease, and primary saccade gain and FEP gain did not vary as a function of delay. Hypometria of primary saccades is compatible with dysfunction in striato-collicular inhibitory pathways in Parkinson's disease, arising as a functional consequence of dopamine deficiency in the basal ganglia. Maintenance of an accurate FEP gain suggests no deficit in oculomotor spatial working memory in Parkinson's disease, at least at delays of up to 5 sec.

Attention

The 'dedicated airway': a review of the concept and an update of current practice.

The term 'dedicated airway' was first used in connection with nasal fibreoptic intubations using the cuffed nasopharyngeal airway. Since that time, the concept has developed and the term has been extended to include fibreoptic intubation techniques involving both the laryngeal mask airway and cuffed oropharyngeal airway. 'Dedicated airway' can now be defined as: 'An upper airway device dedicated to the maintenance of airway patency while other major airway interventions are anticipated or are in progress. The device should be compatible with spontaneous and controlled ventilation. 'Dedicated airway techniques allow planned fibreoptic intubations in difficult cases and provide an emergency airway option in an unexpected difficult intubation when the alternative may be to wake the patient. As well as promoting safe conditions for training fibreoptic intubation in general, there is the particular advantage of being able to train using these techniques in patients known to be difficult to intubate. The authors' evolved clinical experiences in promoting the concept and the relevant literature are reviewed.

Fiber Optic Technology

Relationship between acid tolerance, cytoplasmic pH, and ATP and H+-ATPase levels in chemostat cultures of Lactococcus lactis.

The acid tolerance response (ATR) of chemostat cultures of Lactococcus lactis subsp. cremoris NCDO 712 was dependent on the dilution rate and on the extracellular pH (pHo). A decrease in either the dilution rate or the pHo led to a decrease in the cytoplasmic pH (pHi) of the cells, and similar levels of acid tolerance were observed at any specific pHi irrespective of whether the pHi resulted from manipulation of the growth rate, manipulation of the pHo, or both. Acid tolerance was also induced by sudden additions of acid to chemostat cultures growing at a pHo of 7.0, and this induction was completely inhibited by chloramphenicol. The end products of glucose fermentation depended on the growth rate and the environmental pHo of the cultures, but neither the spectrum of end products nor the total rate of acid production correlated with a specific pHi. The rate of ATP formation was not correlated with pHi, but a good correlation between the cellular level of H+-ATPase and pHi was observed. Moreover, an inverse correlation between the cytoplasmic levels of ATP and pHi was established. Each pHi below 6. 6 was characterized by unique levels of ATR, H+-ATPase, and ATP. High levels of H+-ATPase also coincided with high levels of acid tolerance of cells in batch cultures induced with sublethal levels of acid. We concluded that H+-ATPase is one of the ATR proteins induced by acid pHi through growth at an acid pHo or a slow growth rate.

Adenosine Triphosphate

Fibreoptic intubation using the cuffed oropharyngeal airway and Aintree intubation catheter.

A cuffed oropharyngeal airway has recently been introduced which has larger internal dimensions than a comparable Guedel airway. This allows a ventilation/exchange bougie, the Aintree Intubation Catheter, mounted on a fibreoptic laryngoscope to pass through it. Its 15-mm connector and pharyngeal cuff suggested the possibility of using a Rüsch sealed-port angle piece to allow ventilation through the oropharyngeal airway during fibreoptic laryngoscopy. This study investigated using this equipment to intubate the trachea through the cuffed oropharyngeal airway in paralysed patients, whilst maintaining ventilation manually with a Bain system. In 20 patients, airway control was satisfactory throughout and tracheal intubation was accomplished without complications. The cuffed oropharyngeal airway was easy to manipulate to improve a suboptimal fibreoptic view of the larynx. This may give it an advantage over the laryngeal mask airway when used as a ventilation/intubation conduit.

Adolescent

Rapid detection of rabies and rabies-related viruses by RT-PCR and enzyme-linked immunosorbent assay.

A rapid detection method for the six established genotypes of rabies and rabies-related viral RNA using RT-PCR-ELISA is described. The detection of digoxigenin-labelled amplified products is performed by solution hybridization to two specific, biotin-labelled, capture probes, which are complementary to the inner region of the amplification products. The capture probe and amplified product hybrid are then immobilised on a streptavidin-coated microtitre plate, bound products are detected by an anti-DIG Fab fragment conjugated to peroxidase, and colorimetric reaction automatically measured. This method was up to 100-fold more sensitive than Southern blot hybridization, detecting 0.00002 TCID50/ml of a genotype 1, classical rabies virus strain. The complete detection methodology from RT-PCR to PCR-ELISA detection could be completed within 10 h. Using this procedure, we were 100% successful in detecting 60 isolates from a representative selection of the six established genotypes from all over the world. This test is a useful additional tool for the detection of the rabies and rabies-related viruses, which is easy to perform, rapid and highly sensitive.

Animals

Bartter's syndrome in pregnancy: a case report and review.

Bartter's syndrome is a rare autosomal recessive disorder characterized by hypokalemia, hyperaldosteronism, sodium wasting, normal blood pressure, hypochloremic alkalosis, and hyperplasia of the juxtaglomerular apparatus. We present a 21-year-old African-American nulliparous patient who was referred to our clinic at 9 weeks' gestation with a history of Bartter's syndrome. Her antenatal course was complicated by muscle cramps, which required increasing potassium supplementation. She developed hypomagnesemia in the third trimester of pregnancy, which necessitated magnesium therapy. She delivered an unaffected infant at term. Bartter's syndrome, although extremely rare in pregnancy, requires prompt recognition and careful management, as it may have significant maternal and neonatal implications.

Adult

Intracellular pH is a major factor in the induction of tolerance to acid and other stresses in Lactococcus lactis.

This study demonstrates that exposure of log-phase Lactococcus lactis subsp. cremoris 712 cells to mildly acid conditions induces resistance to normally lethal intensities of environmental stresses such as acid, heat, NaCl, H2O2, and ethanol. The intracellular pH (pHi) played a major role in the induction of this multistress resistance response. The pHi was dependent on the extracellular pH (pHo) and on the specific acid used to reduce the pHo. When resuspended in fresh medium, cells were able to maintain a pH gradient even at pHo values that resulted in cell death. Induction of an acid tolerance response (ATR) coincided with an increase in the ability of cells to resist change to an unfavorable pHi; nevertheless, a more favorable pHi was not the sole reason for the increased survival at acid pHo. Cells with an induced ATR survived exposure to a lethal pHo much better than did uninduced cells with a pHi identical to that of the induced cells. Survival following lethal acid shock was dependent on the pHi during induction of the ATR, and the highest survival was observed following induction at a pHi of 5.9, which was the lowest pHi at which growth occurred. Increased acid tolerance and the ability to maintain a higher pHi during lethal acid stress were not acquired if protein synthesis was inhibited by chloramphenicol during adaptation.

Acetic Acid

Heminested PCR assay for detection of six genotypes of rabies and rabies-related viruses.

A heminested reverse transcriptase PCR (hnRT-PCR) protocol which is rapid and sensitive for the detection of rabies virus and rabies-related viruses is described. Sixty isolates from six of the seven genotypes of rabies and rabies-related viruses were screened successfully by hnRT-PCR and Southern blot hybridization. Of the 60 isolates, 93% (56 of 60) were positive by external PCR, while all isolates were detected by heminested PCR and Southern blot hybridization. We also report on a comparison of the sensitivity of the standard fluorescent-antibody test (FAT) for rabies antigen and that of hnRT-PCR for rabies viral RNA with degraded tissue infected with a genotype 1 virus. Results indicated that FAT failed to detect viral antigen in brain tissue that was incubated at 37 degrees C for greater than 72 h, while hnRT-PCR detected viral RNA in brain tissue that was incubated at 37 degrees C for 360 h.

Animals

A ventilation-exchange bougie for fibreoptic intubations with the laryngeal mask airway.

The ventilation-exchange bougie is a new airway device which can be mounted on a fibreoptic laryngoscope for passage through the larynx into the trachea via a laryngeal mask airway. Subsequent removal of the fibreoptic laryngoscope and laryngeal mask airway allows a tracheal tube to be railroaded into position over the ventilation-exchange bougie. This study described the use of this technique for elective tracheal intubation in two groups of 12 subjects in whom difficulty with intubation was not expected. All the subjects were successfully intubated by one of two anaesthetists, one experienced and the other inexperienced with fibreoptic intubation techniques. Neither had had prior experience with the ventilation-exchange bougie. Because ventilation was maintained throughout the procedure, intubation did not need to be hurried. Cusum analysis confirmed the impression of a learning curve and the technique could be considered learnt after four and six intubations for the experienced and inexperienced fibreoptic laryngoscopists respectively. No difficulty was found either in intubating the larynx with the fibreoptic laryngoscope and ventilation-exchange bougie or when railroading the tracheal tube over the ventilation-exchange bougie. It is suggested that this new device could have an important role in teaching fibreoptic techniques, management of the difficult airway and failed intubations.

Adult

Oculomotor function in amyotrophic lateral sclerosis: evidence for frontal impairment.

Saccadic eye movements, fixation, and smooth pursuit were recorded in 17 subjects with amyotrophic lateral sclerosis (ALS) and 11 age-matched controls using a magnetic scleral search coil. Reflexive, remembered and antisaccades, and smooth pursuit at four target velocities were studied. Subjects with ALS showed significantly elevated error rates (distractibility) and latency in the antisaccade and remembered saccade paradigms but no abnormality of reflexive saccades. The frequency of small saccades that intruded on steady fixation (square-wave jerks) was also increased in ALS subjects. Peak velocity gain of smooth pursuit and performance on the Wisconsin Card Sort Test did not differ significantly between the two groups. These findings are consistent with prefrontal dysfunction in ALS and provide an independent source of support for the thesis that the pathology of this condition invades frontal cortex.

Adult

Plastination for gross anatomy teaching using low cost equipment.

Plastination offers a means of keeping anatomical specimens without the usual problems associated with wet specimens ie desiccation, mould and specific storage requirements. Plastinated specimens are clean and odourless, require minimal aftercare and can be stored on shelves or in display cases. These specimens are more durable and robust than wet specimens showing similar features. The techniques described in this paper for plastination are cost effective, and produce good quality, robust specimens using low cost equipment which is readily available in most Anatomy departments. The procedures described are easy to follow used in conjunction with von Hagens [4] plastination technical notes.

Anatomy

Septic patients in multiple organ failure can oxidize infused glucose, but non-oxidative disposal (storage) is impaired.

1. Patients suffering trauma and sepsis are insulin resistant, but no studies have specifically been made of patients suffering multiple organ failure. 2. We have studied exogenous glucose utilization in multiple organ failure using a combination of the hyperglycaemic glucose clamp and indirect calorimetry to quantify glucose utilization in multiple organ failure, partitioning it into oxidative and nonoxidative disposal (storage). 3. Fourteen septic patients with multiple organ failure were studied. APACHE II (Acute Physiological and Chronic Health Evaluation Mark II) scores on the day of the study ranged from 11 to 31 (median 16). Twenty percent D-glucose was infused and blood glucose was clamped at 12 mmol/l for 3 h. The results were compared with those obtained on seven healthy control subjects. 4. Glucose utilization and energy expenditure were similar in the two groups for the first 90 min of the clamp, after which glucose utilization and energy expenditure increased steadily in the control subjects but did not change in the patients. Respiratory exchange ratio rose in both groups; considered over the whole of the clamp period, respiratory exchange ratio was slightly lower in the patients than in the control subjects (P < 0.05) but not at any specific time point. Glucose oxidation rose in both groups but non-oxidative glucose disposal (storage) rose only in the control subjects. Glucose oxidation was slightly lower in the patients (P < 0.05) but not at any specific time point and there was no difference between the groups in the amount by which glucose oxidation increased. Non-oxidative disposal in the patients fell significantly (P < 0.01) over the course of the clamp and was significantly lower than in the control subjects (P < 0.01). 5. Growth hormone increased in response to glucose infusion in the patients but not in the control subjects. 6. Like patients suffering uncomplicated sepsis or trauma, patients with multiple organ failure are also insulin resistant. The defect appears to lie in an impairment of the ability to store glucose rather than oxidize it, and this may be due in part to the increase in growth hormone in patients with multiple organ failure.

Adolescent

Manipulation of substrate utilization with somatostatin in patients with secondary multiple organ dysfunction syndrome.

OBJECTIVES: To determine whether glucose utilization and metabolic substrate (glucose and fat) oxidation could be manipulated in patients with secondary multiple organ dysfunction syndrome. DESIGN: Prospective study. SETTING: Intensive care units (ICU) of two university hospitals. PATIENTS: Eight adults free of hepatic disease and hemodynamically stable at the time of study, but with failed respiratory and gastrointestinal systems, who thus required mechanical ventilation and intravenous nutrition. INTERVENTIONS: Patients were infused with 20% dextrose through central venous cannulas at rates that increased and maintained (clamped) their plasma glucose concentration at 216 mg/dL (12 mmol/L) for 3 hrs. Somatostatin was infused continuously during the second and third hours of the clamp to reduce plasma concentrations of endogenous insulin and glucagon. Exogenous insulin was administered together with somatostatin during the third hour to restore basal insulin concentrations. Energy expenditure was measured by indirect calorimetry throughout the study and blood samples were withdrawn regularly for determination of metabolite and hormone concentrations. Main statistical comparisons were made between the baseline data (first hour of the study) and data collected during the second and third hours of the clamp. MEASUREMENTS AND MAIN RESULTS: Plasma glucagon concentrations were reduced by nearly 50% (p < .05) toward the end of the study, whereas no significant changes in plasma concentrations of cortisol or growth hormone occurred. Energy expenditure did not change significantly at any time during the clamp procedure. Glucose utilization (6.1 mg/kg/min [34 mumol/kg/min]) during the first hour of the hyperglycemic clamp, decreased by 53% (p < .05) with the infusion of somatostatin during the second hour of the clamp. However, once exogenous insulin was infused during the third hour, glucose utilization increased by 55% (p < .05) when compared with the baseline (hour 1) rate. Glucose oxidation was nearly doubled during the third hour of the study when compared with oxidation rates during the first and second hours. Fat oxidation decreased steadily during the 3-hr clamp. CONCLUSIONS: Glucagon has a significant inhibitory effect on glucose utilization during intravenous glucose infusion in the multiple organ dysfunction syndrome patient. Pharmacologic intervention with somatostatin and insulin (physiologic dose) can facilitate glucose utilization and oxidation in these patients. Further investigations are needed to determine whether long-term alteration of glucose and fat metabolism would be beneficial in the patient with secondary multiple organ dysfunction syndrome.

Aged

Eye movements.

Explore the source record for details and available documents.

Electronystagmography