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Biomedical subjects

B Sweeney

Publications and source records attributed to B Sweeney.

At least 19 recordsLinked to original sources
PubMed2002

Minimum duration of reactivation at 3 months of age.

Briefly exposing subjects to an isolated component of an event after they have forgotten can reactivate their memory of it, leading to renewed retention on an ensuing test. In two experiments with forty-eight 3-month-old infants, we asked what minimum duration of a reactivation treatment could recover their forgotten memory of an operant mobile task and whether the minimum duration was affected by how long the memory was forgotten. In Experiment 1, the minimum duration for reactivating the memory 1 week after forgetting was 120 s-substantially longer than the minimum duration required for reactivation at 6 months after the same relative delay. In Experiment 2, the minimum effective duration for reactivation increased linearly with the time since forgetting, from 7.5 s after 1 day to 180 s after 3 weeks. This study reveals that the duration of an effective memory prime is directly related to age and to memory accessibility.

Attention↗
PubMed2002

New onset seizures in the elderly: aetiology and prognosis.

Late onset epilepsy is increasing in incidence. These patients often have significant underlying morbidity. This retrospective study in a tertiary referral centre identified 68 patients aged 65 years or older, with new onset seizures over a four-year period. 81% of patients (n = 55) were followed up at an average of 2.7 years post diagnosis. 38% of patients had evidence of cerebrovascular disease (CT visualised focal infarction, haemorrhage or small vessel ischaemia in 32%, clinical diagnosis with normal CT brain in 6%). No patient was found to have a space-occupying lesion. Of the 55 patients followed up, 45% of these had died at a mean age of 82 years old and 1.9 years post diagnosis (range 12 hours to 5 years). Three patients died as a direct result of seizures (trauma and sepsis). 14 patients died of clearly unrelated causes. Eight patients died from underlying vascular disease or Alzheimer's dementia. Patients who died during follow-up were on average 3.4 years older at the time of diagnosis than survivors (p< 0.05). Patients with atrial fibrillation at the time of diagnosis, had increased mortality (relative risk 2.53; 95% C.I. 1.19 - 5.36), but they were older than those without atrial fibrillation. At the time of follow up, 92% of those taking anti-convulsants were maintained seizure free on anticonvulsant monotherapy.

Age Factors↗
PubMed2002

Vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney: treatment and outcome.

PURPOSE: Horseshoe kidney is the most common renal fusion anomaly. We determined the treatment and outcome of vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney. MATERIALS AND METHODS: We reviewed the medical and radiological records of 52 consecutive children, including 32 boys and 20 girls, in whom horseshoe kidney was diagnosed at 2 children's hospitals during 1990 to 1999. Patient age at diagnosis was 1 day to 12 years (mean 3.9 years). In 2 children with horseshoe kidney neuropathic bladder was secondary to spina bifida and they were excluded from study. The diagnosis was made in all cases by abdominal ultrasound and confirmed by excretory urography or (99m)technetium-dimercaptosuccinic acid scan. Voiding cystourethrography was performed in 40 cases (80%). Patients were followed for 2 to 11 years (mean 4.2). RESULTS: Associated urological anomalies were identified in 26 patients (52%) with horseshoe kidney, including primary vesicoureteral reflux in 13, ureteropelvic junction obstruction in 12 and ectopic ureter in 1. Surgical intervention to correct the anomalies in 15 of the 26 children (58%) involved pyeloplasty in 8, ureteral reimplantation in 2, endoscopic treatment for vesicoureteral reflux in 2, ureterolithotomy in 1, upper pole heminephrectomy in 1 and valve fulguration in 1. No significant complications were observed in surgically treated patients. CONCLUSIONS: More than half of the patients with a clinically symptomatic horseshoe kidney have vesicoureteral reflux or ureteropelvic junction obstruction. Many patients with horseshoe kidney require surgical intervention for associated urological anomalies with good results.

Child↗
PubMed2001

Polyunsaturated fatty acids influence neonatal monocyte survival.

The n-3 and n-6 polyunsaturated fatty acids (PUFAs) are essential dietary constituents. They are potent modulators of the human immune response, and research has endeavoured to optimise the ratio of n-3 to n-6 fatty acids in the lipid emulsion component of total parenteral nutrition to harness their beneficial effects in the clinical setting. PUFAs modulate apoptosis of certain tumour cells and cell lines. Monocytes, which are major effector cells of the innate immune system, play a central role in the initiation, development, and outcome of the immune response. They are crucial in the defence against invading pathogens and are involved in the lysis of infected or malignant cells, wound healing, repair, and remodeling of tissues. In the present study we investigated whether PUFAs might evoke apoptosis in newborn monocytes. Purified cord-blood monocytes collected from uncomplicated full-term pregnancies were incubated for 24 h in complete medium in the presence or absence of one of the n-3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic (EPA) or the n-6 PUFA arachidonic acid (AA). Following incubation, cells were triple-labelled with annexin V, CD14, and propidium iodide prior to flow-cytometric analysis to determine the degree of cell death. All experiments were performed in triplicate and data expressed as mean +/- 1 S.D. (%). In the absence of fatty acids, 30 +/- 4% of control cord monocytes underwent apoptosis or necrosis after 24 h incubation. At a concentration of 50 microM, none of the PUFAs had a significant effect on monocyte cell death, but at a dose of 100 microM, DHA resulted in 60 +/- 4% cell death (P < 0.05) while the other PUFAs had no significant effect. In contrast, at higher concentrations (200 microM), all the PUFAs significantly increased monocyte cell death (AA: 70 +/- 5%, DHA: 86 +/- 2%, EPA: 70 +/- 4%). PUFAs thus exert a potent influence on cord monocyte cell survival in vitro. Their effect is dose-dependent and DHA appears to be the most potent of the fatty acids tested. The influence of PUFAs on neonatal monocyte-cell survival suggests a novel mechanism whereby PUFAs may modulate the immune response.

Apoptosis↗
PubMed2001

Reflux nephropathy in infancy: a comparison of infants presenting with and without urinary tract infection.

PURPOSE: We compared the incidence of renal scarring in infants with high grade vesicoureteral reflux in those presenting with and without urinary tract infection. METHODS AND METHODS: We reviewed the medical records of 81 male and 46 female infants (194 renal refluxing units) with a mean age of 4 months who had grade IV or V primary vesicoureteral reflux and underwent an anti-reflux procedure between 1984 and 1997. Dimercapto-succinic acid (DMSA) scans and voiding cystourethrography were performed in all cases. Patients were followed for 2 to 16 years, including 90% for greater than 3 years. Renal ultrasound and DMSA scan were done at followup. RESULTS: A total of 97 patients (76%) (148 refluxing renal units) presented clinically with urinary tract infection. The initial DMSA scan demonstrated renal scarring in 40 of the 106 grade IV (38%) and 28 of the 42 grade V (67%) refluxing renal units. There was no scarring on followup in previously normal refluxing renal units. Of the patients 30 (24%) (46 refluxing renal units) were diagnosed before a urinary tract infection developed, 16 underwent screening due to vesicoureteral reflux in a sibling and in 10 reflux was initially suspected due to hydronephrosis on prenatal ultrasound. In the remaining 4 patients vesicoureteral reflux was suspected during abdominal ultrasound to investigate abdominal pain, jaundice, associated hypospadias and fetal alcohol syndrome, respectively. DMSA scan showed evidence of scarring in 6 of 21 grade IV (29%) and 9 of 25 grade V (36%) refluxing renal units in this group. Followup revealed scarring in only 1 previously normal refluxing renal unit. CONCLUSIONS: The incidence of reflux nephropathy in primary grade V vesicoureteral reflux is lower in cases detected by screening and with treatment it remained lower than in cases of urinary tract infection that presented clinically. Early treatment of grade V vesicoureteral reflux made possible by screening may prevent renal damage.

Adolescent↗
PubMed2001

Jejunoileal atresia and associated malformations: correlation with the timing of in utero insult.

PURPOSE: Duodenal atresia is associated with a higher incidence of associated congenital malformations than jejunoileal atresia, supporting the hypothesis that the duodenal obstruction occurs early in fetal life. In this study, the authors analyzed the incidence of major associated malformations in jejunal atresia (JA) and ileal atresia (IA) to determine if there is a positive correlation between the proximity of the intestinal atresia and the association of other major anomalies. METHODS: Records of all patients with jejunoileal atresias treated at the authors' institution between 1980 and 1997 were examined. RESULTS: There were 83 patients with jejunoileal atresias, 38 with JA, and 45 with IA. Sixteen (42%) of the JA patients had an associated major congenital malformation, whereas only 1 (2%) of the IA patients had an associated malformation. A single atresia was found in 18 (47%) of JA patients and 41 (91%) of IA patients. Twenty (53%) of the JA patients had either multiple or apple-peel atresia. Thirteen patients (16%) died, 11 with JA, and 2 with IA. Of the 11 patients with JA who died, 6 had multiple atresias, 4 had cystic fibrosis, and 1 had small bowel volvulus. CONCLUSION: The higher incidence of associated major congenital extraintestinal malformations in JA compared with IA patients suggests that some cases of JA may arise from a malformative process.

Abnormalities, Multiple↗
PubMed2001

The Bioinformatics Template Library--generic components for biocomputing.

MOTIVATION: The efficiency of bioinformatics programmers can be greatly increased through the provision of ready-made software components that can be rapidly combined, with additional bespoke components where necessary, to create finished programs. The new standard for C++ includes an efficient and easy to use library of generic algorithms and data-structures, designed to facilitate low-level component programming. The extension of this library to include functionality that is specifically useful in compute-intensive tasks in bioinformatics and molecular modelling could provide an effective standard for the design of reusable software components within the biocomputing community. RESULTS: A novel application of generic programming techniques in the form of a library of C++ components called the Bioinformatics Template Library (BTL) is presented. This library will facilitate the rapid development of efficient programs by providing efficient code for many algorithms and data-structures that are commonly used in biocomputing, in a generic form that allows them to be flexibly combined with application specific object-oriented class libraries. AVAILABILITY: The BTL is available free of charge from our web site http://www.cryst.bbk.ac.uk/~classlib/ and the EMBL file server http://www.embl-ebi.ac.uk/FTP/index.html

Algorithms↗
PubMed2000

New diabetes outreach network model created.

In conclusion, collaboration between the MDON, MNA, and DCP resulted in the development of a statewide model for offering MNA-approved continuing education to MDON contract agencies and the community. Educational programs are standardized, current, based on clinical practice and education standards, and taught uniformly throughout the state. Our next step will be to determine whether the patient outcomes of the CQL Project show a correlation between presentations conducted and positive outcomes for patient care and treatment.

Diabetes Mellitus↗
PubMed1999

Infants' memory processing of a serial list: list length effects.

Six-month-olds, trained with a three-mobile serial list, exhibit a primacy effect 24 h later. In three experiments, we demonstrated that increasing list length impairs their memory for serial order. In all experiments, 6-month-olds were trained with a five-mobile list. In Experiment 1, infants failed to exhibit a primacy effect on a 24-h delayed recognition test, recognizing mobiles from all serial positions. In Experiment 2, infants did exhibit a primacy effect on a reactivation (priming) test, suggesting that they may originally have encoded serial-order information. Experiment 3 confirmed that serial-order information was represented in infants' training memory. After the reactivation treatment, infants were precued with one list member and tested for recognition of another. When precues specified valid order information, infants recognized test mobiles from the later serial positions. The memory dissociation for serial order on delayed recognition and reactivation tests adds to the growing evidence that young infants possess two functionally distinct memory systems.

Analysis of Variance↗
PubMed1998

Postoperative nausea and vomiting in arthroscopic day-case surgery: a comparison between desflurane and isoflurane.

We compared the postoperative effects, in particular nausea and vomiting, of two commonly used anaesthetic agents, isoflurane and desflurane, in patients undergoing day-case arthroscopic surgery. We found a significantly higher incidence of postoperative nausea and vomiting in those patients receiving desflurane. In our study, desflurane was associated with a higher incidence of peroperative respiratory complications, including airway irritability and coughing.

Adolescent↗
PubMed1998

Evidence of CNS impairment in HIV infection: clinical, neuropsychological, EEG, and MRI/MRS study.

OBJECTIVES: To identify by clinical examination, EEG, MRI, and proton spectroscopy, and neuropsychological assessment the prevalence of signs of CNS involvement in patients infected with HIV, and to relate such findings to the evidence of immunosuppression. METHODS: The design was a cross sectional analysis of a cohort of male patients with infected HIV with an AIDS defining diagnosis or low CD4 count (<350), and seropositive asymptomatic subjects, both groups being followed up in a longitudinal study. Control groups consisted of seronegative subjects from the same genitourinary medicine clinics. RESULTS: This report sets out the cross sectional findings at the seventh visit in the longitudinal study. Patients with AIDS had more signs of neurological dysfunction, poorer performance on a neuropsychological test battery, were more likely to have an abnormal EEG, and to have abnormalities on MRI. They more often had cerebral atrophy, abnormal appearing white matter, and abnormal relaxometry and spectroscopy. There was little evidence of abnormality in seropositive people who had a CD4 count >350 compared with seronegative people from a similar background. CONCLUSIONS: Detailed testing failed to disclose significant CNS impairment without immunosuppression in men infected with HIV. Findings from MRI and magnetic resonance spectroscopy (MRS) correlated with those of the neurological examination and neuropsychological assessment. A combination of such assessments offers a simple surrogate for studies of CNS involvement in HIV disease.

AIDS Dementia Complex↗