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Biomedical subjects

A J Tierney

Publications and source records attributed to A J Tierney.

At least 19 recordsLinked to original sources
PubMed1999

Serotonin-like immunoreactivity in the stomatogastric nervous systems of crayfishes from four genera.

We used whole-mount immunocytochemistry to characterize the distribution of serotonin in the stomatogastric nervous systems of seven species of crayfish representing three genera from the family Cambaridae (Orconectes, Cambarus, and Procambarus) and one from the family Astacidae (Pacifastacus). In all species, we observed serotonin-like immunoreactivity in four gastropyloric receptor (GPR) neurons located in the lateral ventricular nerves, with one pair of neurons in each nerve. As in other crustaceans, the GPR axons project to the stomatogastric ganglion and to the bilateral commissural ganglia. In three crayfishes, we observed the GPR axons crossing the commissural ganglia, and extending toward the thoracic nervous system. This feature was most clearly and consistently seen in Pacifastacus leniusculus. The number of stained somata in the commissural ganglia varied among crayfish species from two (in Procambarus clarkii) to five (in Pacifastacus leniusculus). The largest soma (the L cell) displayed both serotonin- and tyrosine hydroxylase-like immunoreactivity in all species, suggesting that serotonin and dopamine are cotransmitters in this cell. The inferior esophageal nerve and a branch of this nerve (the inner labral nerve) contained several axons with serotonin-like immunoreactivity. These axons were clearly present in only one species (Procambarus clarkii). Serotonin acts as a neuromodulator of rhythms produced by circuits in the crab and lobster stomatogastric ganglion, and is likely to play a similar role in crayfish. Differences are apparent in the distribution of serotonin among crayfish species and between crayfish and other crustaceans, and could result in differences in the physiological action of this modulator.

Animals↗
PubMed1998

Nursing models: extant or extinct?

Although nursing models have always had their sceptics, they are now being subjected to more sustained criticism. Critiques have tended to focus mostly on the value of models for nursing practice but, increasingly, their place in nursing science is also being questioned. Reed believes that the growing disparagement of nursing models is symptomatic of the tensions between modernist and postmodernist perspectives on nursing. Drawing its title from Reed's discussion, this paper--from the opposite side of the Atlantic--reflects on the original purpose of nursing models and critically examines their relevance now, using the first and best-known British nursing model (the Roper-Logan-Tierney model for nursing) as the particular example for scrutiny. Although the popularity of this model is acknowledged, Fraser highlights the concern that it has not been tested. Can, and should, models be tested? This question is addressed in view of its apparent importance to the debate about whether or not nursing models have any continuing, legitimate role in theory or in practice.

Humans↗
PubMed1997

FMRFamide-like peptides in the crayfish (Procambarus clarkii) stomatogastric nervous system: distribution and effects on the pyloric motor pattern.

Whole-mount immunocytochemistry was used to map the location of FMRFamide-like peptides in the crayfish (Procambarus clarkii) stomatogastric nervous system. This system contains the pyloric and gastric mill central pattern generators, which receive modulatory inputs from projection neurons with somata located primarily in other ganglia of the stomatogastric nervous system. Our studies revealed stained somata in the commissural and esophageal ganglia. A pair of stained somata was located in the inferior ventricular nerve, and another pair of somata was located in the stomatogastric nerve where it is joined by the two superior esophageal nerves. The stomatogastric ganglion contained no stained somata, but the neuropil was brightly stained and 2-4 axons projected laterally in small nerves directly from the ganglion. These results indicate that FMRFamide or related peptides may act as neuromodulators in the crayfish stomatogastric nervous system. To test this hypothesis, we studied the effects of FMRFamide and four related peptides (DF2, NF1, F1 and LMS) on the pyloric motor pattern. DF2, NF1 and F1 all excited certain pyloric cells, especially the lateral pyloric (LP) and ventricular dilator (VD) neurons, and enhanced pyloric cycling frequency in most actively rhythmic preparations. FMRFamide had no detectable effects on pyloric cells, and LMS had inhibitory effects, causing disruption of the pyloric rhythm in actively cycling preparations and reducing tonic activity in non-rhythmic preparations.

Animals↗
PubMed1996

Venovenous extracorporeal membrane oxygenation: the effects of proximal internal jugular cannulation.

Venovenous (VV) extracorporeal membrane oxygenation (ECMO) using a double lumen catheter has become an accepted method of providing ECMO support for critically ill newborn infants. In addition, use of the cephalic jugular catheter can provide augmented venous blood flow, potentially prevent increased cerebral venous pressure, maintain cerebral venous blood flow, and increase ECMO oxygen delivery. The authors compared their experience using VV double-lumen (VVDL) ECMO with a cephalic jugular catheter with their previous experience using venoarterial (VA) ECMO. They compared 15 infants who had meconium aspiration syndrome (MAS) and 12 who had congenital diaphragmatic hernia (CDH) treated with VVDL ECMO with a cephalic jugular catheter with the same number of infants with each condition treated with VA ECMO (historical controls). There were no significant differences between the groups with respect to birth weights, oxygen indexes before ECMO, of ECMO flows at 4 and 24 hours. For infants with MAS treated with VVDL ECMO, the overall duration of ECMO support was significantly shorter (63 hours VVDLv 118 hours VA; P = .001), and the average cephalic flow was 33 mL/kg for infants treated with VVDL support. For infants with CDH, there were no differences in any of the variables evaluated, including total duration (100 hours VVDLv 128 hours VA; P = .06 [NS]), and the average cephalic flow was 39 mL/kg for infants treated with VVDL support. The venous oxygen content was significantly lower in infants with MAS treated with VVDL ECMO than for historical controls treated with VA ECMO at 4 hours of ECMO support (15.8 v 16.7; P < or = .05). No other significant differences were noted for any of the calculated oxygen transport variables comparing VVDL with VA ECMO infants with CDH treated with VVDL ECMO were extubated sooner than those treated with VA ECMO (10.3 days VVDL v 15.4 days VA; P = 048). In addition, there was no significant difference in the overall incidence of complications or death. This experience suggests that VVDL ECMO using a cephalic jugular catheter results in shorter ECMO runs and provides support that is comparable to VA ECMO for infants with CDH and MAS while avoiding carotid artery cannulation and ligation.

Cardiac Catheterization↗
PubMed1996

Undernutrition and elderly hospital patients: a review.

Numerous surveys have revealed that many hospital patients are undernourished. Elderly patients are particularly vulnerable to the adverse consequences of undernourishment. Slow acquisition and application of available knowledge has been blamed as a principle reason for lack of progress in tackling the problem of 'hospital malnutrition'. This paper provides a resumé of the knowledge accumulated from research with the purpose of promoting active and informed nursing involvement in the detection and management of undernutrition in hospital wards.

Age Distribution↗
PubMed1995

Congenital diaphragmatic hernia: associated malformations--cystic adenomatoid malformation, extralobular sequestration, and laryngotracheoesophageal cleft: two case reports.

Two infants with unusual bronchopulmonary malformations associated with congenital diaphragmatic hernia (CDH) are presented. One infant had extralobular sequestration and cystic adenomatoid malformation of the lower lobe, in addition to a left-sided CDH. The second infant had a laryngotracheoesophageal cleft extending to the carina (type III) in addition to a left-sided CDH. These associated malformations can have major implications in terms of diagnosis, resuscitation, and surgical management of infants with CDH.

Abnormalities, Multiple↗
PubMed1995

Inhaled nitric oxide for premature infants after prolonged rupture of the membranes.

We evaluated the use of inhaled nitric oxide in eight premature infants (520 to 1440 gm, 24 to 31 weeks of gestation) who failed to respond to conventional management and who had prolonged rupture of the membranes and oligohydramnios. All infants had a significant improvement in oxygenation and a fall in mean airway pressure with inhaled nitric oxide. Further studies are required to determine the safety and efficacy of this form of therapy.

Administration, Inhalation↗
PubMed1995

HIV/AIDS--knowledge, attitudes and education of nurses: a review of the research.

This paper provides a review of research relating to knowledge, attitudes and education of nurses in relation to HIV/AIDS. Early studies portrayed nurses (and other health-care workers) as fearful of AIDS, ill-informed, and negative and discriminatory in their attitudes towards people with HIV/AIDS. Several major surveys in the UK in the late 1980s produced broadly similar findings and, in the absence of more recent countering evidence, it cannot be assumed that there has been significant improvement. Research surveys of HIV/AIDS education provision for nurses are also reviewed. A recent survey of UK nursing colleges revealed weaknesses in provision, and a lack of training and confidence among nurse teachers. Although evaluation research has been scarce, some studies have demonstrated the beneficial effects of various forms of education on nurses' HIV/AIDS-related knowledge and attitudes, and these are also reviewed. Although early predictions of a rapidly escalating AIDS epidemic have proved to be exaggerated, at least in developed countries, it is vital that nurses do not become complacent. This review should encourage nurses, irrespective of clinical specialty, to reconsider their own knowledge and attitudes and to press for further HIV/AIDS education if they consider that it is still lacking.

Curriculum↗
PubMed1994

Inhaled nitric oxide in infants referred for extracorporeal membrane oxygenation: dose response.

To determine the role of inhaled nitric oxide (NO) in a population of critically ill hypoxic near-term infants and to determine the dose response to inhaled NO, we examined a consecutive group of 23 infants referred for neonatal extracorporeal membrane oxygenation (ECMO) who had an oxygen index of 20 or greater after treatment with bovine surfactant. Inhaled NO was administered in concentrations from 5 to 80 ppm in random order to 23 infants. Overall, 13 infants had a significant response (an improvement in arterial oxygen pressure > 10 mm Hg or arterial oxygen saturation > 10%) to the first administration of inhaled NO, and one infant had a late response. There was no significant difference in the response to inhaled NO as measured by changes in arterial oxygen pressure or in the alveolar-arterial difference in partial pressure of oxygen, for any of the doses from 5 to 80 ppm. Thirteen infants had echocardiographic evidence of persisted pulmonary hypertension; 11 of these infants responded, compared with 3 responders among the 10 infants without persistent pulmonary hypertension of the newborn (p < 0.01). Overall, 11 infants required ECMO; there were two deaths in this group. Seven infants had congenital diaphragmatic hernia; five of those had a response to NO inhalation and four required ECMO. Our study demonstrates that there is no significant difference in response between low and high doses of inhaled NO and that this treatment may prevent the need for ECMO in some infants referred for this therapy, especially in infants with pulmonary hypertension. Prospective, controlled, randomized, and blinded trials of low doses of inhaled NO are needed to determine the clinical role of this potentially useful therapy.

Administration, Inhalation↗
PubMed1994

An analysis of nursing's performance in the 1992 assessment of research in British universities.

Nursing was rated as lowest of all 72 subjects reviewed in the 1992 assessment of research in British universities. Of the 29 academic nursing departments assessed, 17 received the lowest possible rating and only five were given an average or above average rating. Immediate coverage of these results in the nursing press was slow and superficial, and sometimes misleading. This paper explains how the Research Assessment Exercise (RAE) was carried out. It is argued that academic nursing departments are crucial to the profession in its current pursuit of an improved research capability and productivity and, therefore, that the results of the RAE should be of interest and concern to nurses. The analysis presented of nursing's results shows that the larger, longer-established departments based in research-strong 'old' universities have more research-active staff, and it was these departments that received the best ratings in the RAE. In contrast, most of the nursing departments assigned the lowest possible rating were small, recently established departments in 'new' universities that could not have been expected to distinguish themselves in their first research assessment. It is suggested, however, that any new academic nursing departments should be strategically placed in research-strong universities. Although this paper is concerned with nursing in British universities, the general notion of research funding being allocated on the basis of performance is (or is likely to become) pertinent to other countries, especially those in Europe, North America and Australasia.

Education, Medical↗
PubMed1994

Measuring the costs and quality of palliative care: a discussion paper.

In an era of ever increasing emphasis on cost-effectiveness of health care, and with the introduction of the internal market, there is now an urgent need for information on the costs and quality of palliative care. This paper highlights the complexities involved in acquiring and measuring such information and discusses methods which were tried out in an exploratory study. The study took the form of in-depth case studies in two hospices, one in the voluntary sector and one in the NHS.

Consumer Behavior↗
PubMed1993

Conducting research interviews with elderly people by telephone.

Telephone interviews were employed by nurse researchers as a means of collecting data from elderly people following their discharge from hospital. The paper reviews the literature concerning interviews with elderly patients by telephone and recounts first-hand experience of the method on the basis of over 500 telephone interviews. Although some difficulties were encountered in conducting interviews with the hearing-impaired and the unwell, the method was found to be a cost-effective and useful means of obtaining follow-up data for research purposes. The prime factor in ensuring successful use of the method was the recruitment of subjects via personal interview prior to telephone contact.

Aged↗
PubMed1993

The complexities of using a structure, process and outcome framework: the case of an evaluation of discharge planning for elderly patients.

Effective planning for discharge from hospital of elderly patients is becoming increasingly important as the elderly population rises. Donabedian's structure-process-outcome framework was used for an evaluation of discharge planning at a large teaching hospital. This paper discusses first the difficulties of defining the boundaries between each of the three Donabedian categories, and then makes some suggestions as to what factors require inclusion when considering the structures, processes and outcomes of discharge planning for elderly patients.

Aged↗
PubMed1993

Challenges for nursing research in an era dominated by health service reform and cost containment.

Many health care systems around the world are under reform, not least for reason of necessary cost containment. As one of the largest items of a health service budget, the costs of nursing services are attracting particular attention. This behooves the nursing profession, if only in its own interest, to accumulate convincing evidence of the cost-effectiveness of nursing. Nursing's research track record in the assessment of the costs, quality, and effectiveness of nursing is assessed in this paper and found to be generally weak. The complexity of such research is acknowledged; the need for research which will insure and demonstrate the highest quality of nursing at the lowest possible cost is presented as a key challenge for nurse researchers in the present era.

Cost Control↗
PubMed1992

Neonatal congenital diaphragmatic hernia and extracorporeal membrane oxygenation.

OBJECTIVE: To describe the outcome of infants with congenital diaphragmatic hernia (CDH) presenting early who were referred for possible extracorporeal membrane oxygenation (ECMO). DESIGN: Retrospective descriptive study. SETTING: Neonatal Intensive Care Unit of the Royal Alexandra Hospital, Edmonton. PATIENTS: Fifteen infants referred to our program since its introduction, in February 1989; 13 received ECMO. The criterion for ECMO was the presence of an oxygen index of more than 40 on three occasions within 2 hours. INTERVENTION: ECMO was performed by means of cannulation of the right carotid artery and jugular vein for 111.0 hours on average. RESULTS: In 5 of the 13 infants who underwent ECMO the procedure was performed after surgical repair; all were successfully weaned off ECMO, and the cannula was removed without incident. In the remaining eight ECMO was started before surgical repair; of the six who received it during repair four ultimately survived. None of the previously described predictors of outcome for CDH, including diagnosis before 25 weeks' gestation (in six cases), were useful in determining the survival of the patients. Bleeding was the most common complication and cause of death. CONCLUSION: ECMO is associated with survival in infants with CDH who fail to respond to conventional therapy and who have a poor prognosis according to previously established criteria.

Extracorporeal Membrane Oxygenation↗
PubMed1992

A rare intrapericardial mass in a neonate.

We describe a rare case of a neonate born with an intrapericardial mass composed of extralobar pulmonary sequestration and a cyst of bronchogenic origin. After an uneventful delivery, this full-term newborn was noted to be grunting and indrawing. He remained tachypneic despite adequate management for bilateral pneumothoraces. Diagnostic studies showed a 3 x 3 x 4 cm diameter cystic lesion in the anterior mediastinum causing posterior-lateral displacement of the superior vena cava. The heart itself was structurally normal. Bronchoscopy and esophagoscopy failed to detect any structural abnormalities. At 3 weeks of age, sternotomy and resection of the lesion was performed. The mass was clearly intrapericardial and consisted of sequestrated pulmonary tissue with a unilocular mucus filled bronchogenic cyst. Small systemic tributaries fed the lesion from the posterior-superior aspect. There was no connection with the heart or great vessels. Postoperative recovery was uneventful.

Bronchi↗