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Biomedical subjects

B Connolly

Publications and source records attributed to B Connolly.

13 recordsLinked to original sources
PubMed1992

The changing role of surgery in the management of rhabdomyosarcoma.

A retrospective analysis was performed of 56 patients presenting to Our Lady's Hospital for Sick Children, Crumlin, Dublin, Ireland, over a 25 year period with a diagnosis of rhabdomyosarcoma, in an effort to assess the changing role of surgery in the management of this disease. There were 38 males and 18 females; the age range at presentation was from birth to 13 years with a median of three years. Head and neck tumors occurred most frequently (23) followed by pelvic (14), paratesticular (6), extremities (6), gastrointestinal (4) and thoracic (3). Prior to 1971 there were no survivors while a doubling of survival has been observed within the past decade (31% to 63%). The minimum period of follow-up was four years. Surgical intervention ranged from total primary excision (20) to biopsy only (21) with total or subtotal resection performed electively in 15. Surgical evaluations, including examinations under anesthesia, staging laparotomy and second look laparotomy were also invaluable in assessing disease status. The incorporation of multiagent chemotherapy together with more selective use of radiotherapy has enabled a more conservative role to be adopted by the surgical oncologist thereby minimizing longterm sequelae.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Biological roles of the Escherichia coli RuvA, RuvB and RuvC proteins revealed.

In Escherichia coli, the ruvA, ruvB and ruvC gene products are required for genetic recombination and the recombinational repair of DNA damage. New studies suggest that these three proteins function late in recombination and process Holliday junctions made by RecA protein-mediated strand exchange. In vitro, RuvA protein binds a Holliday junction with high affinity and, together with RuvB (an ATPase), promotes ATP-dependent branch migration of the junction leading to the formation of heteroduplex DNA. The third protein, RuvC, which acts independently of RuvA and RuvB, resolves recombination intermediates by specific endonucleolytic cleavage of the Holliday junction.

Adenosine Triphosphate↗
PubMed1991

Resolution of Holliday junctions in vitro requires the Escherichia coli ruvC gene product.

In previous studies, Holliday junctions generated during RecA-mediated strand-exchange reactions were resolved by fractionated Escherichia coli extracts. We now report the specific binding and cleavage of synthetic Holliday junctions (50 base pairs long) by a fraction purified by chromatography on DEAE-cellulose, phosphocellulose, and single-stranded DNA-cellulose. The cleavage reaction provided a sensitive assay with which to screen extracts prepared from recombination/repair-deficient mutants. Cells with mutations in ruvC lack the nuclease activity that cleaves synthetic Holliday junctions in vitro. This deficiency was restored by a multicopy plasmid carrying a ruvC+ gene that overexpressed junction-resolving activity. The UV sensitivity and deficiency in recombinational repair of DNA exhibited by ruv mutants lead us to suggest that RuvC resolves Holliday junctions in vivo.

Bacterial Proteins↗
PubMed1990

Genetic recombination in Escherichia coli: Holliday junctions made by RecA protein are resolved by fractionated cell-free extracts.

Escherichia coli RecA protein catalyzes reciprocal strand-exchange reactions between duplex DNA molecules, provided that one contains a single-stranded gap or tail, to form recombination intermediates containing Holliday junctions. Recombination reactions are thought to occur within helical RecA-nucleoprotein filaments in which DNA molecules are interwound. Structures generated in vitro by RecA protein have been used to detect an activity from fractionated E. coli extracts that resolves the intermediates into heteroduplex recombinant products. Resolution occurs by specific endonucleolytic cleavage at the Holliday junction. The products of cleavage are characteristic of patch and splice recombinants.

Adenosine Triphosphate↗
PubMed1989

Localized amyloidosis of seminal vesicles: report of three cases in surgically obtained material.

Localized amyloidosis of the seminal vesicles (ASV) is reported as an incidental finding in surgical specimens from three elderly men. In two cases, the amyloid deposits were bilateral, subepithelial, and clinically inapparent, features similar to other cases in the literature. In one case, the diagnosis was made on a transrectal prostatic needle biopsy that included a small portion of seminal vesicle; to our knowledge, this has not been previously reported. Electron microscopy in one case demonstrated nonbranching fibrils characteristic of amyloid, and pretreatment of tissue sections using the permanganate method in two cases showed almost complete ablation of congophilia. Evidence suggests that ASV is a permanganate-sensitive, non-AA (amyloid, protein A) type of amyloid that may be different from all other types of amyloid previously characterized.

Aged↗
PubMed1988

Has vesicostomy a role in the neuropathic bladder?

This retrospective study aims to assess the efficacy of vesicostomy in the management of deteriorating upper renal tracts in patients with neuropathic bladders for whom intermittent self catheterization is not a clinical option. Between 1980-1987 vesicostomy was performed in 16 such patients (11 female, 5 male). Eleven had myelomeningocoele, 4 sacral anomalies and one cerebral palsy with scoliosis. All patients had urinary tract infections and deteriorating hydronephrosis and hydroureter (IVP, U/S); associated reflux in 13, impaired GFR in 4 and abnormal biochemistry in 8. The mean age at surgery was 3.3 years (8 mths. to 9 years). In all cases deterioration was arrested by vesicostomy. Fifteen patients showed structural or functional improvement and one stabilized. Late closure of the vesicostomy in two cases resulted in disimprovement of biochemical and radiological parameters. Acceptance of the vesicostomies was good. We advocate vesicostomy as an effective drainage procedure to preserve function in patients with neuropathic bladders and deteriorating renal tracts, in whom intermittent self catheterization is not a realistic alternative.

Child↗
PubMed1988

Physical monitoring of mating type switching in Saccharomyces cerevisiae.

The kinetics of mating type switching in Saccharomyces cerevisiae can be followed at the DNA level by using a galactose-inducible HO (GAL-HO) gene to initiate the event in synchronously growing cells. From the time that HO endonuclease cleaves MAT a until the detection of MAT alpha DNA took 60 min. When unbudded G1-phase cells were induced, switched to the opposite mating type in "pairs." In the presence of the DNA synthesis inhibitor hydroxyurea, HO-induced cleavage occurred but cells failed to complete switching. In these blocked cells, the HO-cut ends of MATa remained stable for at least 3 h. Upon removal of hydroxyurea, the cells completed the switch in approximately 1 h. The same kinetics of MAT switching were also seen in asynchronous cultures and when synchronously growing cells were induced at different times of the cell cycle. Thus, the only restriction that confined normal homothallic switching to the G1 phase of the cell cycle was the expression of HO endonuclease. Further evidence that galactose-induced cells can switch in the G2 phase of the cell cycle was the observation that these cells did not always switch in pairs. This suggests that two chromatids, both cleaved with HO endonuclease, can interact independently with the donors HML alpha and HMRa.

DNA↗
PubMed1988

Pledgets in ingrowing toenails.

Eighty children had cotton wool pledgets inserted under the nail corner for ingrowing toenails. Success was achieved in 44 (72%) of the 61 children followed up for a mean of 2.5 years. Appearance was excellent and compliance high. Initial insertion under anaesthesia improved the results, and chronicity did not adversely affect the outcome.

Adolescent↗
PubMed1987

CSF/shunt infections--the bane of our lives!

Thirty one patients were treated for 43 laboratory proven shunt or CSF infections, between 1980 to 1986 inclusive. They required 63 separate treatments. Infective episodes were grouped retrospectively according to method of treatment employed i.e. 1) placement of external drainage system or 2) reservoir and tapping, 3) intravenous or intraventricular antibiotics alone, 4) total change of shunt prosthesis, 5) partial change of prosthesis or 6) removal of all the prosthesis. See Table II. The single most important factor in eradication of shunt infection was the entire removal of the total shunt system and achieved success in 80% of instances. Conversely utilization of any of the existing infected system failed in 77% of cases. Route of administration of antibiotics, choice or change of side, or method of treatment chosen did not appear to influence success greatly.

Bacterial Infections↗
PubMed1987

Trends in tracheoesophageal fistula.

The changing trends in the management of patients with esophageal atresia, with or without tracheoesophageal fistula during 1974 to 1983, and its effect on survival and morbidity rates are analyzed herein. Of 139 patients in this series, 44 per cent were in Waterston group C. The over-all mortality rate was 25.5 per cent but this decreased consistently after 1980 to 11.0 per cent in 1983. The incidence of infants in the series who weighed less than 1.8 kilograms at birth increased from 7 per cent before 1979 to 18 per cent after 1979 and the survival rate increased from zero to 50 per cent. All six infants who were 30 to 34 weeks gestation and referred after 1979 survived. Severe pneumonia at admission decreased from 24 to 11 per cent in two five year periods. Delayed primary anastomosis and Livaditis circular myotomy overcame many problems of the "long gap" associated with pure esophageal atresia, resulting in successful anastomosis in all eight patients treated in the latter years. Of six patients who presented before 1979, three patients died and three required interposition grafts. Significant anastomotic leaks decreased from 14.7 to 3.2 per cent and the mortality rate decreased from 70 to zero per cent, reflecting many factors, such as extrapleural repair, use of total parenteral nutrition and improved neonatal, ventilatory and intensive care.

Abnormalities, Multiple↗
PubMed1976

Interdisciplinary early intervention program.

Developmental data were obtained on 40 children with Down's syndrome by an interdisciplinary team during an ongoing early intervention program. Interventive methods are described. Results are compared with available data on children with Down's syndrome who were not in early intervention programs. Comparisons of developmental progress are also made of children begun in the early intervention program before six months of age with those begun after six months of age. Conclusions from the study indicate that early intervention helps the child in earlier attainment of many developmental tasks and enhances functioning of the family unit.

Counseling↗