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Biomedical subjects

P Byrne

Publications and source records attributed to P Byrne.

At least 19 recordsLinked to original sources
PubMed2006

Hydroview lens implant calcification: 186 exchanges at a district general hospital.

AIM: This paper describes the experience at a district general hospital of coping with an abrupt onset of calcification of Hydroview intraocular lens (IOL) implants requiring exchange surgery mostly for symptoms of glare, even though the visual acuities were relatively good. METHODS: In this retrospective study, the operative details of 174 consecutive lens exchanges by one surgeon were retrieved from the surgeon's notes. Of these, pre and post-operative details of 106 consecutive patients were obtained from the hospital notes. RESULTS: Of the 174 lens exchanges, all were sutureless except one and 31 eyes (18%) had had previous capsulotomies. Of 143 eyes with intact posterior capsules, eight (5.6%) needed anterior vitrectomy. Lens replacements were in the bag in 136 (95%), in the sulcus in five (3.5%), and in the anterior chamber in two (1.5%). Of the 31 eyes with previous capsulotomies, 10 (32%) needed anterior vitrectomy. Lens replacements were in the bag in 22 (71%) and in the sulcus in the remaining nine cases (29%). Postoperatively the best-corrected visual acuity was improved in 53%, remained the same in 35%, and deteriorated in 12%. CONCLUSION: The lens exchange procedure was mostly predictable with satisfactory visual results allowing preoperative counselling of risks to be similar to that for cataract surgery. The onset and resolution of the period of implantation of lenses requiring exchange has not been explained.

Aged↗
PubMed2006

Pregnancy outcome in immigrant women in the Rotunda Hospital.

In recent years the numbers of immigrants attending maternity hospitals has risen. The amount of antenatal care these women receive varies widely. Analysis was performed of deliveries to immigrant women in the Rotunda Hospital in 2002. Women were sub-divided depending on antenatal care received in Ireland. Women who received no antenatal care were 'unbooked', those who attended the hospital two to 28 days before delivery were 'late bookers'. The remaining women were 'booked'. There were 1,954 deliveries to immigrant women; 1,1 73 (60%) 'booked', 391 (20%) 'late bookers' and 390 (20%) 'unbooked'. 'Unbooked' women had a higher rate of spontaneous vertex delivery (63%) (p < 0.01). 'Late bookers' had a higher rate of caesarean section (27.6%) (p < 0.01). The 'late bookers' infants were more likely to be preterm, low birth weight and had a higher rate of neonatal ICU (NICU) admissions (p < 0.01). This study has identified 'late booker' immigrants as a high-risk group.

Adolescent↗
PubMed2006

Is vaginal breech delivery outdated for all singletons and twins? The current kaleidoscope of obstetric thinking.

The best practice for the delivery of a term breech in singleton and twin pregnancies is still controversial. We sought the opinions of obstetricians working in Ireland. A questionnaire was used to address the management of the obstetrician's "own hypothetical pregnancy" in three different scenarios. We also inquired about factors which might influence the decision on mode of delivery. The response rate was 104/174 (60%). In the scenario of a singleton fetus presenting by the breech in a nulliparous woman, 15/84 (18%) of obstetricians would chose a spontaneous vaginal delivery compared to 40/80 (50%) for a multiparous woman (p < 0.01). In the scenario of a second twin in breech presentation (nulliparous and multiparous), 75/93 (81%) would choose a spontaneous vaginal delivery. When asked about a singleton cephalic presentation, 85/91 (93%) would choose a spontaneous vaginal delivery. These decisions were influenced by concerns about perinatal morbidity [91/100 (91%)], published evidence [73/98 (75%)], the delivery doctor's inexperience [56/94 (60%)], but not by gender. Our study indicates that obstetricians in Ireland consider that there is a role for vaginal breech delivery in selected scenarios.

Attitude of Health Personnel↗
PubMed2006

Study of ovarian cancer management.

Ovarian cancer is the most lethal gynecological malignancy. Many patients present at an advanced stage as the symptoms of early stage disease can be vague. AIM We evaluated the demographics, treatment regimens and survival rates of ovarian cancer patients attending Beaumont Hospital Dublin over a nine year period. A retrospective chart review of ovarian cancer patients attending Beaumont Hospital between 11/10/94 and 30/6/3 was performed. Patients were selected from pathology records. Patients with borderline histology and those who died of unrelated causes were excluded. 31% of individuals presented with distension as their only clinical sign. 20% presented with a mass as their only clinical sign. The most common cell type was papillary serous adenocarcinoma in two thirds of cases. 54% presented with advanced disease [stage IIl-IV]. Treatment involved surgical clearance or debulking +/- chemotherapy. 5 year survival for Stage I was 95% versus 19% for Stage IlI. This highlights the importance of early diagnosis.

Adult↗
PubMed2006

Smoking and alcohol in pregnancy. Survey in the immediate post-partum period.

This was a questionnaire-based study of 151 postnatal women. We found 42% of women were smokers prior to pregnancy and only 37% of these women succeeded in quitting smoking during pregnancy. Success in quitting was significantly related to the number of cigarettes smoked (p<0.05). However, 71% of pregnant smokers were aware of the associated risks. Alcohol was consumed by 89% of women and 10% admitted to binge drinking during pregnancy. Only 44% of the study group were aware of the associated risks of alcohol. We propose that we need to change our social acceptance of these behaviours before pregnancy, and provide support to those women during pregnancy.

Adolescent↗
PubMed2004

Audit of thromboprophylaxis in women undergoing caesarean section.

Thromboembolism is a major cause of maternal mortality. Pregnancy is associated with an increased risk of thromboembolic diseases, with an even greater risk in women undergoing caesarean section. Since the introduction of the RCOG guidelines in 1995 on thromboprophylaxis for women undergoing caesarean section, there has been a significant reduction in the number of women dying from pulmonary embolism in the UK. The aims of our study was to conduct an audit cycle to assess our compliance with RCOG guidelines for thromboprophylaxis in women undergoing caesarean section to introduce changes in practice based on the observations of this audit, and to re-audit our practice to assess the effect of the changes. A retrospective audit of 100 women undergoing caesarean section was done in the Rotunda Hospital in June 2001. Changes in practice were introduced based on the findings of this audit. Obstetricians were asked to complete a checklist pre-operatively and to assign the patients a risk category-low, moderate or high. Prophylaxis was prescribed based on this risk assessment. Following the introduction of this change in practice, we re-audited 100 women delivered by caesarean section in June 2002. In the first audit, risk assessment was as follows: 20 low, 75 moderate and 5 high. Twenty-one of 75 (28%) of moderate risk patients in the first audit received appropriate prophylaxis. In the re-audit, risk assessment was as follows: 33 low, 66 moderate and 1 high. Following the introduction of new clinical practice, 45 of 66 (68%) of those in the moderate risk group received appropriate prophylaxis. All women in the low risk groups received appropriate prophylaxis in both audits. Our audit cycle of thromboprophylaxis in women undergoing caesarean section has demonstrated that the introduction of new clinical practice resulted in greater compliance with the RCOG guidelines, but further improvement could be achieved. These observations are discussed and recommendations are made to further improve compliance with RCOG guidelines.

Adolescent↗
PubMed2004

The evaluation and treatment of female urinary incontinence--a comparison of clinical practice in the Republic of Ireland with the recommendations of the International Continence Society.

In 1998 the International Continence Society (ICS) developed a set of recommendations for the diagnostic evaluation and treatment of urinary incontinence. The aim of this study was to determine to what extent current clinical practice in the Republic of Ireland correlated with the ICS recommendations. We personally interviewed 100 gynaecologists at units around Ireland. Participants were presented with two clinical scenarios, one described a patient with predominantly genuine stress incontinence, the other described a patient with an overactive bladder. Ninety-five (95%) requested a midstream urine sample for culture and sensitivity, and 74 (74%) considered urodynamics an appropriate initial investigation for a woman with stress incontinence. Physiotherapy was recommended as a first line treatment for stress incontinence by 76 (76%). Burch colposuspension, chosen by 55 (55%), was the most common first line surgical procedure. Other first line surgical procedures were TVT [31(31%)] Marshall-Marchetti-Krants procedure [5(5%)], anterior colporrhaphy [4 (4%)] and a variety of other procedures [5 (5%)]. When considering the initial investigation for a woman with an overactive bladder, 95 (95%) asked for a midstream urine sample for culture and sensitivity and 85 (85%) requested urodynamic investigations. Initial management of this condition included anticholinergic therapy alone [57 (57%)], anticholinergic therapy combined with bladder retraining [36 (36%)], bladder retraining alone [5 (5%)], and cystoscopy and bladder distension 2 (2%). Seventy-six (76%) felt that cystoscopy was an appropriate investigation for a woman with symptoms of an overactive bladder who has failed to respond to initial therapy. The study reveals a significant degree of diversity in the evaluation and management of patients who present with symptoms of urinary incontinence. It also highlights a number of areas where current clinical practice deviates from the recommendations of the ICS. In particular, there is a high and inappropriate use of urodynamics in the initial management of these patients.

Adult↗
PubMed2003

A new predictor of cephalopelvic disproportion?

Cephalopelvic disproportion (CPD) is a recognised obstetric problem with potential risk to both mother and infant. Identification of those mothers at risk of CPD is difficult and has concentrated in the past on such measurements as maternal shoe size and height. Our objective in this study was to examine new anthropomorphic parameters as indicators of CPD. This was a case controlled study of sixty consecutive women, and their partners, who had caesarean section performed for CPD and 60 case matched controls. Measurements included maternal and paternal head circumference, height, shoe-size, body mass index (BMI), infant weight and head circumference. Parity, gestation at delivery, and mode of onset of labour were recorded. Data were analysed using Stata Release 6. Prognostic factors were tested for association with CPD using conditional logic regression. The most important anthropomorphic risk factors for CPD were maternal head circumference in relation of height (P < 0.001), and paternal head to height ratio (P = 0.017). Head to height ratio is taken as the head circumference in centimeters divided by the height in metres. Body mass index was higher in CPD cases (maternal case mean = 27.1, control mean = 25.5; paternal case mean = 27.2, control mean = 26.2). Infant head circumference was not a predictor. Primiparity was an important independent predictor (P<0.001), regardless of the mode of onset of labour. Maternal or paternal shoe-size, induction of labour and gestation at delivery were not predictors. The risk profile for CPD which emerges is one of a tall father where both mother and father have large head-to-height ratios.

Adult↗
PubMed2003

Deep brain stimulation of the subthalamic nucleus: effectiveness in advanced Parkinson's disease patients previously reliant on apomorphine.

OBJECTIVES: To assess the efficacy of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with advanced Parkinson's disease previously reliant on apomorphine as their main antiparkinsonian medication. METHODS: Seven patients with motor fluctuations despite optimal medical treatment given as predominantly apomorphine infusion (n=6), or intermittent apomorphine injections (n=1) underwent bilateral STN DBS using frameless stereotactic surgery. Standard assessments of parkinsonism and motor fluctuations, using Unified Parkinson's Disease Rating Scale (UPDRS) were performed before and six months after surgery. Assessments were performed both on and off medication, and postoperative with the stimulators switched on and off. RESULTS: Bilateral STN DBS improved motor scores (UPDRS III) by 61% when off medication (p<0.05). Clinical fluctuations (UPDRS IV items 36-39) were reduced by 46.2% (p<0.05). Total daily apomorphine dose was reduced by 68.9% (p<0.05) and apomorphine infusion via a pump was no longer required in four patients. There were no operative complications. Two patients required treatment for hallucinations postoperatively but there was no significant change in mini-mental state examination. CONCLUSIONS: In patients with advanced Parkinson's disease, previously reliant on apomorphine, bilateral STN DBS is an effective treatment to reduce motor fluctuations and enable a reduction in apomorphine use.

Aged↗
PubMed2003

Variability in position of the subthalamic nucleus targeted by magnetic resonance imaging and microelectrode recordings as compared to atlas co-ordinates.

BACKGROUND: Traditional methods for localisation of target nuclei for deep brain stimulation (DBS) have used brain atlas co-ordinates for initial targeting. It is now possible to visualise the subthalamic nucleus (STN) on magnetic resonance imaging (MRI) and determine the individual variability of its position. METHODS: The present study was performed in patients undergoing STN DBS for Parkinson's disease. The STN was directly targeted from axially obtained MRI and verified with microelectrode recordings. Postoperatively, the most effective contact was identified for each patient, and its position was calculated. RESULTS: Fifty electrodes were inserted in 25 patients. The target position varied considerably in relation to the mid-commissural point. The mean effective contact position lies just dorsal to the location of the STN in a standard brain atlas. CONCLUSION: The STN varies in position, and can be accurately targeted from MRI alone.

Adult↗
PubMed2003

Use of the NeuroMate stereotactic robot in a frameless mode for movement disorder surgery.

BACKGROUND/AIMS: To evaluate the use of the NeuroMate stereotactic robot with a novel ultrasound registration system for movement disorder surgery (MDS). METHODS: Using the robot in a frameless mode, 51 patients underwent MDS. Surgical planning was carried out using MRI data obtained more than 24 h before surgery. RESULTS: 37 out of 50 targets in the subthalamic nucleus were satisfactorily identified with a single microelectrode trajectory and the final electrode positions were at a mean distance of 1.7 mm from the calculated target. There was a significant improvement in motor scores of the Unified Parkinson's Disease Rating Scale III (off medication) at 6 (43%) and 18 months (51.7%) compared to pre-operative scores (p < 0.05). CONCLUSIONS: The frameless robot using only MRI data can be used for MDS. The temporal separation of imaging from the surgical procedure provides additional time for detailed image analysis and planning.

Humans↗
PubMed2002

Importance of radiotherapy in the outcome of patients with primary CNS lymphoma: an analysis of the CHOD/BVAM regimen followed by two different radiotherapy treatments.

PURPOSE: To assess the effect of a reduced dose of radiotherapy (RT) in patients with primary CNS lymphoma (PCNSL) responding to the cyclophosphamide, doxorubicin, vincristine, and dexamethasone (CHOD)/carmustine, vincristine, methotrexate, and cytarabine (BVAM) regimen. PATIENTS AND METHODS: Patients received one cycle of CHOD and two of BVAM. In the first trial, all 31 patients received 45-Gy whole-brain RT (CHOD/BVAM I). In the second, with 26 patients, RT dose was reduced to 30.6 Gy if there was a complete response (CR) after chemotherapy (CHOD/BVAM II). RESULTS: Age, performance status, and chemotherapy received were similar in both protocols. CR rate at the end of all treatment was 68% for CHOD/BVAM I and 77% and for CHOD/BVAM II. Treatment modality was the only predictor of relapse, with 3-year relapse risks of 29% and 70% for CHOD/BVAM I and II, respectively. This was specifically important in the 25 patients less than 60 years old (3-year relapse risk, 25% v 83%; P =.01). The 5-year overall survival (OS) was 36%. Age (< 60 v > or = 60 years) was the only predictor for OS in the multivariate analysis (relative risk, 2.1; 95% confidence interval, 1.4 to 2.8). RT dose was the only predictor of OS in patients younger than 60 years old who achieved CR at the end of all treatment (3-year OS, 92% v 60% for patients receiving 45 or 30.6 Gy, respectively; P =.04). CONCLUSION: Reduction of the RT dose from 45 Gy to 30.6 Gy in patients younger than 60 years old with PCNSL who achieved CR resulted in an increased risk of relapse and lower OS.

Actuarial Analysis↗
PubMed2002

Pharmacological salvage of a combined distal bypass and free flap with catheter-directed thrombolysis.

With recent improvements in microvascular techniques, the use of combined distal bypass and free-flap transfer has been advocated for salvaging the critically ischaemic limb in extreme conditions. Distal bypass, however, carries an inherent risk of graft failure due to thrombosis, and this may threaten the viability of the free flap and, indeed, the lower limb. We present the case of a 66-year-old man with acute-on-chronic ischaemia of his left leg and rectus abdominis free flap. Despite a prolonged ischaemic time of 72 h, both were successfully salvaged using catheter-directed recombinant tissue plasminogen activator. This is previously unreported in the literature.

Aged↗
PubMed2002

Chimerism analysis in sex-mismatched murine transplantation using quantitative real-time PCR.

Marine experimental stem cell transplantations require the accurate discrimination and quantification of donor cells from host cells. A Y-chromosome-specific, quantitative real-time PCR (kinetic PCR) protocol for blood-derived DNA was developed. The assay sensitivity was extremely high with accurate detection of only 10 pg (six copies of Y target DNA) in a variable background of female DNA background ranging from 2.5 to 50 ng. The dynamic range of the assay provided accurate results ranging from 2.2 x 10(-2)% to 100% of male DNA in female background. The kinetic PCR assay can be used in all mouse strains, and a sample size as low as 2.5 ng total DNA is sufficient for analysis. Therefore, kinetic PCR allows engraftment kinetic studies on repeated blood draws of individual animals with no need for sacrifice. Compared to conventional PCR, the assay is much simplified, as neither the accurate adjustment of sample DNA concentration nor a post-reaction analysis procedure is required. The procedure is simple, free of radioactivity, and permits a throughput of 500-600 reactions per day.

Animals↗
PubMed2002

Perinatal outcome in unbooked women at the Rotunda Hospital.

To determine the incidence and outcome of unbooked pregnancies in women at the Rotunda Hospital Retrospective case control study. All unbooked deliveries in the Rotunda Hospital over a two year period were identified and matched with a control. Control patients were selected as the next delivery after each case and were regular antenatal attenders. Demographic and obstetric data was collected from each case and control and compared using the Chi-square test. There were 101 unbooked women in the study, during this time there were 11522 deliveries giving an incidence of unbooked pregnancies of 0.88%. Unbooked women were found to be young, multiparous, unemployed and unmarried. They were more likely to deliver by spontaneous vaginal delivery to preterm, low birth weight infants and were at greater risk of a stillbirth and neonatal death. Unbooked pregnancies account for a small proportion of our antenatal population. However, perinatal outcome is significantly worse in unbooked patients compared to those who are regular antenatal attenders.

Adult↗
PubMed2001

Identification of gene clusters differentially expressed during the cellular injury responses (CIR) to cisplatin.

The goal of this study was to identify changes in mRNA levels in tumour cells after a toxic exposure to cisplatin (IC(99)dose). Using suppression-subtractive hybridization (SSH) 2 cDNA libraries were created, an UP library (202 cDNA fragments) and a DOWN library (153 cDNA fragments). Using reversed Northern hybridization 16 and 30 fragments were truly differentially expressed in the UP and DOWN libraries, respectively. Most prominent in the UP library were the mitochondrial and injury response clusters and in the DOWN library the cytoskeletal, protein synthesis and signalling clusters. These distinct clusters potentially represent an expression profile of the cisplatin-induced cellular injury response.

Antineoplastic Agents↗
PubMed2001

Il-17 mobilizes peripheral blood stem cells with short- and long-term repopulating ability in mice.

Autologous and allogeneic bone marrow transplantations have evolved as important cancer therapy modalities. For both indications, peripheral blood has been shown to have distinct advantages over bone marrow as the stem cell source. Cytokine combinations for mobilization have enhanced stem cell yield and accelerated engraftment. However, novel mobilizing agents and strategies are needed to further improve clinical outcomes. Within the donor graft, the dynamic equilibrium between T cells and stem cells critically influences engraftment and transplantation results. IL-17 is a cytokine produced almost exclusively from activated T cells. IL-17 was expressed in vivo with adenovirus technology. Here, proof-of-principle studies demonstrate that IL-17 effectively mobilizes hemopoietic precursor cells (CFU-granulocyte-erythrocyte-macrophage-monocyte, CFU-high proliferative potential) and primitive hemopoietic stem cells (Lin(-/low)c-kit(+)Sca1(+)). Moreover, mouse IL-17 adenovirus-mobilized peripheral blood stem cells rescued lethally irradiated mice. Bone marrow was found to be 45-75% of donor origin at 1 year. In secondary recipients, donor-derived bone marrow cells ranged from 45 to 95%. These data show that IL-17 mobilizes stem cells in mice with short- and long-term reconstituting capacity. Additional comparative studies are needed as well as studies in tumor models to refine distinct potential clinical applications for IL-17-mobilized peripheral blood stem cells.

Animals↗