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Biomedical subjects

F Regan

Publications and source records attributed to F Regan.

At least 19 recordsLinked to original sources
PubMed2006

Prematurity--another example of perinatal metabolic programming?

Low birth weight is associated with both later adult diseases such as type 2 diabetes mellitus and a number of metabolic abnormalities, the foremost of which is insulin resistance. Indeed the link between an adverse perinatal environment, manifested by low birth weight, and adult life pathology may be an early, permanent reduction in insulin sensitivity. A reduction in insulin sensitivity has been demonstrated in small for gestational age (SGA), term subjects from childhood through to adulthood. Less is known about children born premature into an adverse neonatal environment. We present data demonstrating that premature infants also have metabolic abnormalities similar to those observed in term, SGA children and that these occur irrespective of whether they are SGA or appropriate for gestational age (AGA).

Adipose Tissue↗
PubMed2006

Preoperative autologous blood donation for bone marrow harvests: are we wasting donors' time and blood?

Predeposit autologous blood donation (PAD) is frequently offered to bone marrow donors, but its cost-effectiveness is dubious. We assessed the impact of PAD and bone marrow donation on transfusion requirements; and the use of donated blood units in a retrospective study of 61 bone marrow donors. The mean haemoglobin (Hb) concentration fell from 12.9 to 11.8 g dL(-1) in women who predonated one unit and from 13.2 to 10.9 g dL(-1) in those who predonated two units. In men who donated two units of blood, the Hb concentration decreased to 12.9 g dL(-1). Bone marrow harvest led to a further decline in Hb concentration by 2.3 g dL(-1) in women and by 2.4 g dL(-1) in men. The postharvest Hb fell to or= 9.0 g dL(-1); overtransfusion was even more apparent in men: 71% units were given with a Hb >or= 10.0 g dL(-1). PAD in bone marrow donors is associated with high wastage and increases the likelihood of requiring a transfusion. We recommend that PAD should not be routinely offered to bone marrow donors.

Blood Transfusion, Autologous↗
PubMed2006

Improving the accuracy of estimated blood loss at obstetric haemorrhage using clinical reconstructions.

OBJECTIVES: Following the results of the Confidential Enquiries into Maternal Deaths report, which claims two maternal deaths annually in the UK from postpartum haemorrhage, our aim was to assess the accuracy of 'visual estimation of blood loss' and produce suitable pictorial and written algorithms to aid in the recognition and management of massive obstetric haemorrhage. DESIGN: Observational study to determine discrepancy between actual blood loss (ABL) and estimated blood loss (EBL). SETTING: Teaching hospital. POPULATION: Hundred and three obstetricians, anaesthetists, midwives, nurses and healthcare assistants. METHODS: Clinical scenarios were reproduced in the form of 12 Objective Structured Clinical Examination (OSCE) style stations augmented with known volumes of whole blood. Individual staff estimated the blood loss visually and recorded their results. Digital photographs were used to produce a pictorial 'algorithm' suitable for use as a teaching tool in labour ward. MAIN OUTCOME MEASURES: Areas of greatest discrepancy between EBL and ABL. RESULTS: Significant underestimation of the ABL occurred in 5 of the 12 OSCE stations: 500-ml (50-cm diameter) floor spill, 1000-ml (75-cm diameter) floor spill, 1500-ml (100-cm diameter) floor spill, 350-ml capacity of soaked 45- x 45-cm large swab and the 2-l vaginal postpartum haemorrhage on bed/floor. CONCLUSIONS: Accurate visual estimation of blood loss is known to facilitate timely resuscitation, minimising the risk of disseminated intravascular coagulation and reducing the severity of haemorrhagic shock. Participation in clinical reconstructions may encourage early diagnosis and prompt treatment of postpartum haemorrhage. Written and pictorial guidelines may help all staff working in labour wards.

Algorithms↗
PubMed2005

ABO incompatibility due to immunoglobulin G anti-B antibodies presenting with severe fetal anaemia.

ABO incompatibility is a common haematological problem affecting the newborn. The haemolysis is widely accepted to follow a relatively benign course rarely causing the escalating levels of hyperbilirubinaemia and significant anaemia associated with Rh haemolytic disease of the newborn. Case reports of fetal hydrops secondary to ABO incompatibility are particularly rare. We describe two cases, first that of a twin pregnancy with both fetuses developing severe anaemia at 20 weeks gestation, and then a second case of a preterm baby demonstrating aggressive haemolysis and anaemia within hours of delivery. Both mothers were of black Africian origin and both were identified to have elevated titres of IgG anti-B antibodies.

ABO Blood-Group System↗
PubMed2005

Acute ureteric calculus obstruction: unenhanced spiral CT versus HASTE MR urography and abdominal radiograph.

The aim of this study is to compare the performance of unenhanced spiral CT to the combination of HASTE MR urography (MRU) and plain abdominal radiography (KUB) in patients suspected of having acute calculus ureteric obstruction. 64 patients with suspected acute calculus ureteric obstruction were evaluated. The presence of perirenal fluid, presence and level of ureteric obstruction and calculi were assessed on both techniques. 44 of 64 (69%) patients had acute calculus ureteric obstruction based on clinical, radiographic or surgical findings. MRU showed perirenal fluid in acute ureteric obstruction (77%) with a greater sensitivity than CT showed stranding (45%). The combination of fluid and ureteric dilation on MRU showed a sensitivity of 93% (CT 80%), specificity of 95% (CT 85%), and accuracy of 94% (CT 81%). There were 61 findings of either fluid or ureteric dilatation on MRU in 44 acutely obstructed kidneys compared with 37 similar findings on CT (p<0.005). Although there was excellent reproducibility (Kappa=/>0.75) in the finding of perirenal fluid on MRU, there was only fair interobserver agreement (Kappa<0.4) regarding perirenal stranding on CT. MRU/KUB showed ureteric calculi in 21/29 (72%) of patients with calculi seen by CT. Overall, MRU/KUB revealed 2.4 abnormalities per acutely obstructed ureter compared with 1.8 abnormalities detected by CT. MRU/KUB using HASTE sequences can diagnose the presence of acute calculus ureteric obstruction with similar accuracy to spiral CT. The technique has less observer variability and is more accurate than CT in detecting evidence of obstruction such as perirenal fluid.

Acute Disease↗
PubMed2004

The metabolic consequences of prematurity.

An association between low birth weight, commonly a reflection of an adverse in utero environment, and the subsequent development of diseases such as type 2 diabetes and hypertension in later life is now generally accepted - as is an association between an adverse perinatal environment and a permanent reduction in insulin sensitivity. This and other metabolic abnormalities have been demonstrated from childhood through to adulthood in subjects who were born full-term but small for gestational age (SGA). Less is known about children born prematurely into an adverse neonatal environment. We present data demonstrating that premature infants also have metabolic abnormalities similar to those observed in full-term, SGA children, and that these occur irrespective of whether the premature infants are SGA or appropriate for gestational age (AGA).

Child↗
PubMed2003

Potential of microemulsion electrokinetic chromatography for the separation of priority endocrine disrupting compounds.

This work examines the potential of microemulsion electrokinetic chromatography for the separation of several priority endocrine disrupting compounds (EDCs). The optimised microemulsion system comprised 25 mM phosphate buffer pH 2, 80 mM octane, 900 mM butanol, 200 mM sodium dodecyl sulphate and was further modified with 20% propanol. The use of a low pH buffer resulted in the suppression of electroosmotic flow within the capillary. Reversal of the conventional electrode polarity resulted in faster migration of hydrophobic compounds. Test analytes included the octylphenol, nonylphenol and nonylphenol diethoxylate, which are breakdown products of the alkylphenolic detergents. The synthetic oestrogens diethylstilbestrol and ethynyloestradiol were also included in the separation along with the plastic monomer bisphenol-A. Test analytes were selected due to their reported presence in environmental samples namely industrial and domestic wastewater treatment effluents and sludges. Using the optimised method a separation of six EDCs was achieved within 15 min. The optimised method was then applied to the analysis of a spiked wastewater influent sample with UV detection of all six compounds at 214 nm.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed2002

Development of comparative methods using gas chromatography-mass spectrometry and capillary electrophoresis for determination of endocrine disrupting chemicals in bio-solids.

Two analytical separation techniques are being investigated for their potential in determining a wide range of endocrine disrupting chemicals (EDCs) in the environment. Capillary electrophoresis (CE) in the micellar mode in conjunction with a cyclodextrin (CD) modifier is shown to have potential for determination of alkylphenol breakdown products. Gas chromatography with mass spectrometric (GC-MS) detection is being utilised for validation of the CE method development and in addition as a separation technique to optimise preconcentration using solid-phase extraction. GC has demonstrated potential for the separation of 26 priority chemicals suspected as being endocrine disrupting compounds. The challenge of the method development process lies in the fact that these compounds are of differing polarities, size and charge and therefore are difficult to separate in a single run. Capillary electrophoresis in the CD-MEKC (micellar electrokinetic chromatography) mode is showing potential in this regard. Limits of determination are in the low mg/l range for CE and GC, however, using preconcentration it is possible to improve detection sensitivity with >80% recovery for some analytes and up to 100% recovery for most target species.

Buffers↗
PubMed2002

Are changes in admission practices for elective surgery posing a transfusion threat to patients?

There is an increasing emphasis on reducing in-patient hospital stay for elective surgical procedures. As a result, pre-operative stay has shortened, with less time available for performing baseline investigations before surgery, including those required to ensure a supply of safe, compatible blood. We have estimated the frequency of failure to complete 'group and screen' (G&S) testing before surgery where indicated, so that neither group-compatible blood nor crossmatched blood could be provided promptly if an unexpected haemorrhage occurs. Retrospective data were obtained from elective surgical procedures performed over a 3-week period. Of the 309 procedures performed, 21 patients were exposed to the risk of failure to provide appropriately matched blood had an emergency arisen. (In 20, a G&S was required; in one, a crossmatch was required.) Late samples and lack of information on the request form regarding the date and time of surgery were the main causes. Procedures requiring G&S only as opposed to crossmatch posed the greatest risk. Urgent measures are needed to ensure that, where indicated, a pre-operative G&S result is available before surgery begins. Educating colleagues, redesigning request forms and improving out-of-hour laboratory services and hospital information systems are the main steps needed to reduce this latent risk.

Blood Grouping and Crossmatching↗
PubMed2002

Imaging bowel obstruction: a comparison between fast magnetic resonance imaging and helical computed tomography.

AIM: To compare the accuracy of fast magnetic resonance (MR) imaging using the half-Fourier single shot turbo spin echo (HASTE) sequence with helical computed tomography (CT) in diagnosing bowel obstruction. MATERIALS AND METHODS: Prospective evaluation of 44 patients with clinical evidence of bowel obstruction was conducted using various investigations including HASTE MR and helical CT. MR was performed with a Siemens 1.5 Tesla MR Imaging System and CT was performed with one of two Siemens ARHP CT systems using helical technique. MR acquisition allowed data to be gathered in 6-10 minutes and no contrast media were administered. CT imaging consisted of consecutive helical CT through the abdomen and pelvis with oral and intravenous contrast medium used when indicated. Bowel dilation along with the presence and level of obstruction were determined. RESULTS: Twenty-eight patients had bowel obstruction confirmed at laparotomy or by radiographic assessment. Of these, 25 had small bowel obstruction and three had colonic obstructions. The obstruction was due to fibrous adhesions in nine patients, metastases or primary carcinoma in seven, Crohn's disease in four, hernias in two, and inflammation or abscess in two. Other causes of obstruction included lymphoma, intussusception and anastomotic stricture. The cause of obstruction was correctly diagnosed by CT in 71%, and by MR in 95% of cases. The sensitivity, specificity and accuracy for HASTE MR imaging was 95%, 100% and 96% respectively as compared to 71%, 71% and 71% for helical CT. CONCLUSION: Fast MR imaging using the HASTE sequence is more accurate than helical CT in diagnosing bowel obstruction.

Adult↗
PubMed2000

Plain abdominal x-ray versus computerized tomography screening: sensitivity for stone localization after nonenhanced spiral computerized tomography.

PURPOSE: Urolithiasis followup with plain abdominal x-ray requires adequate visualization of the calculus on the initial x-ray or computerized tomography (CT) study. We compared the sensitivity of plain abdominal x-ray versus CT for stone localization after positive nonenhanced spiral CT. MATERIALS AND METHODS: We evaluated 46 consecutive nonenhanced spiral CT studies positive for upper urinary tract lithiasis for which concurrent plain abdominal x-rays were available. X-ray and CT studies were compared for the ability to visualize retrospectively a stone given its location by CT. A consensus of 1 radiologist and 3 urologists was reached in each case. Cross-sectional stone size and maximum length were measured on plain abdominal x-ray. RESULTS: Plain abdominal x-ray and scout CT had 48% (22 of 46 cases) and 17% (8 of 46) sensitivity, respectively, for detecting the index stone (p <0.00004). Of the 39 stones overall visualized on plain abdominal x-ray only 19 (49%) were visualized on scout CT. Mean cross-sectional area and length of the stones on scout CT were 0.34 cm.2 (approximately 6 x 5.5 mm.) and 6. 5 mm., respectively, while the average size of those missed was 0.11 cm.2 (approximately 4 x 3 mm.) and 3.6 mm. The mean size differences in the groups were highly significant (p <0.0009). CONCLUSIONS: Plain abdominal x-ray is more sensitive than scout CT for detecting radiopaque nephrolithiasis. Of the stones visible on plain abdominal x-ray 51% were not seen on CT. To facilitate outpatient clinic followup of patients with calculi plain abdominal x-ray should be performed when a stone is not clearly visible on scout CT.

Humans↗
PubMed1999

MR cholangiopancreatography using HASTE sequences.

AIM: The aim of this pictorial review is to describe applications of cholangiopancreatography (MRCP) using half-Fourier (HASTE) MR sequences. MATERIALS AND METHODS: 350 patients were imaged over a four-year period with a 1.54 Tesla Siemens Vision scanner and a phased array body coil. The HASTE MR sequence was applied in multiple planes with an acquisition time of 13 seconds allowing breath hold techniques. In addition, a single-shot technique provided single slice acquisitions with a thickness of 20 mm. A chemical fat suppression algorithm reduced intra-abdominal MR high signal. RESULTS: HASTE MRCP accurately determines the presence of level of biliary obstruction in up to 97% of patients. Common bile duct stones are detected with a sensitivity of 93%. Acute cholecystitis is depicted on HASTE MR as pericholecystic high signal in 41/45 (91%) patients and gall stones are detected with a 93% sensitivity. CONCLUSION: HASTE MRCP offers a non-invasive, rapid imaging method to evaluate the gallbladder, common bile duct and pancreas. Its multi-planar, fluid sensitive capabilities are of particular value in detecting common bile duct stones and acute cholecystitis.

Acute Disease↗
PubMed1999

Hydronephrosis in pregnancy: simultaneous depiction of fetal and maternal hydronephrosis by magnetic resonance urography.

Magnetic resonance urographic (MRU) techniques possess image quality and diagnostic capability that are improving with increasingly sophisticated imaging sequences and shorter scanning times. We describe the application of a fast breath-hold MR sequence (HASTE) in the assessment of ureteric obstruction in pregnancy. In the patient presented, HASTE MRU was successful in depicting ureteral anatomy and demonstrated dilation of both ureters below the level of the pelvic brim. This observation suggested distal ureteral obstruction rather than simple hydronephrosis of pregnancy. As a result, bilateral nephrostomies were performed and neonatal prematurity was avoided. Interestingly, in this patient, HASTE MR imaging also showed evidence of concurrent fetal hydronephrosis.

Adult↗
PubMed1999

Ventilation-perfusion scintigraphic evaluation of pulmonary clot burden after percutaneous thrombolysis of clotted hemodialysis access grafts.

The objective of this study is to determine, by using rigorous methods, if pulmonary perfusion defects were detectable by ventilation-perfusion scintigraphy after percutaneous thrombolysis of clotted hemodialysis access grafts. Thirteen patients were studied. Four patients underwent pharmacomechanical thrombolysis with urokinase and the remainder had mechanical thrombolysis alone. Pre- and postthrombolysis scintigraphic studies were performed on all patients. Perfusion defects were described as vascular (well-defined borders confined to segmental boundaries) or nonvascular. Vascular defects were graded by severity (0 to 3) and area (0 to 3) for each involved segment. Nonvascular defects were graded by severity (0 to 1) and area (0 to 1). Two experienced readers evaluated the scans blinded to each other's results and all other clinical data, including thrombolysis outcomes. Twelve patients did not have any significant worsening of their perfusion defect scores postthrombolysis. In only one patient did a study show a new nonvascular perfusion defect with a matching ventilation abnormality. The defect was believed to be caused by mucus plugging. The patient had no evidence of pulmonary embolism. Our study suggests emboli that resulted from the pharmacomechanical or mechanical thrombolysis procedure were either small, underwent lysis before impacting the lung, or were below the limit of detection of ventilation-perfusion scintigraphy.

Adult↗
PubMed1999

Cerebral embolism after mechanical thrombolysis of a clotted hemodialysis access.

Clinically significant embolic complications after thrombolysis of clotted hemodialysis grafts are uncommon. Most of the concern has focused on the risks associated with pulmonary emboli. We report a case of a hemodialysis patient who developed a cerebral embolism after percutaneous graft thrombolysis who was found to have a patent foramen ovale and intermittent right-to-left shunt.

Aged↗