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Biomedical subjects

R J Fitzgerald

Publications and source records attributed to R J Fitzgerald.

At least 55 records · Page 3Linked to original sources
PubMed1989

Surgery for neonatal necrotising enterocolitis in Ireland 1980-1985.

Forty-seven infants were operated on for necrotising enterocolitis (NEC) in Ireland in a 6-year-period from 1980 to 1985. Incidence for surgical NEC in Ireland is 1/8733 live births. 44/47 patients were operated on during the acute phase and 3 patients had elective resection of strictures following conservative management. Indication for surgery in the acute phase was pneumoperitoneum in 37 infants. The initial procedure was: drainage alone in 10 patients, laparotomy and defunctioning enterostomy in 18, resection of the necrotic segment and proximal enterostomy in 15. 27/44 acute patients survived giving an overall mortality of 38.6% for acute NEC but mortality directly related to NEC was 31.8%. There was an inverse relationship between mortality and age at surgery. Medical treatment included total parenteral nutrition (TPN) in all patients for a mean time of 20.5 days.

Cohort Studies↗
PubMed1989

Binding of ions and hydrophobic probes to alpha-lactalbumin and kappa-casein as determined by analytical affinity chromatography.

The technique of analytical affinity chromatography was extended to characterize binding of ions and hydrophobic probes to proteins. Using the immobilized protein mode of chromatography, alpha-lactalbumin and kappa-casein were covalently attached to 200-nm-pore-diameter controlled-pore glass beads and accommodated for high-performance liquid chromatography. The existence of a high affinity binding site (Kdiss = 0.16 microM) (site I) for calcium ion in alpha-lactalbumin was confirmed by chromatography of [45Ca2+]. In addition, chromatography of the hydrophobic probes, 1-(phenylamino)-8-naphthalene-sulfonate (ANS)2 and 4,4'-bis[1-(phenylamino)-8-naphthalenesulfonate (bis-ANS) indicated that Ca2+ bound to a second site (presumably the zinc site or site II) with weaker affinity. Dissociation constants obtained for apo-alpha-lactalbumin were about 80 microM for ANS and 4.7 microM for bis-ANS in the absence of sodium ion. Addition of Ca2+ initially caused a reduction in surface hydrophobicity (lowered affinity for the probe dyes) followed by an increase at higher Ca2+ concentrations (greater than 0.5 mM), suggesting that occupancy of site II restores an apo-like conformation to the protein. Moreover, the effect of Zn2+ was similar to that observed in the higher Ca2+ concentration range, whereas Na+ apparently bound to site I. A calcium binding site of moderate affinity also exists in kappa-casein (Kdiss = 15.6 microM). A cluster of negative charges, probably including the orthophosphate group, most likely comprise this binding site. By preventing self-association, analytical affinity chromatography permits microscale characterization of ligand equilibria in proteins that are unaffected by protein-protein interactions.

Animals↗
PubMed1989

Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

Animals↗
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

An unusual case of complete urethral duplication in a female child.

A case is reported of a female child with complete urethral duplication draining a single bladder and with the accessory urethra communicating with the urachus. The clinical, operative and histological findings suggest that the urethral duplication may represent an abortive duplication of the bladder.

Female↗
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↗
PubMed1988

Corrosive injury of the oesophagus in childhood.

A 10-year retrospective review of 73 children who had ingested a corrosive agent was performed. Presentation, management, and eventual outcome were assessed, and comparisons were made between those who received early medical treatment and those who did not. Results suggested that immediate proper assessment of the oesophagus and institution of appropriate therapy may reduce the incidence of complications associated with treatment of subsequent stricture formation. The importance of oesophagoscopy in the direct visualization of the oesophagus within 24-48 h of the burn is stressed.

Anti-Bacterial Agents↗
PubMed1987

Aberrant thymus: a misleading mediastinal mass.

We report two cases in which aberrant thymic tissue caused a misleading superior mediastinal mass. The diagnosis can be made by awareness of it and by use of appropriate investigations. Should surgery be performed we recommend frozen section biopsy if ectopic thymus is suspected, and if confirmed, the mass should not be excised unless it is causing serious mechanical problems.

Choristoma↗
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↗
PubMed1986

Effects of chlorhexidine gluconate in drinking water on dental caries and oral microorganisms in the Syrian hamster.

Hamsters infected with Streptococcus sobrinus (formerly Streptococcus mutans) strain 6715-1119 were given high-sucrose diet 2000. After 5 days, they were presented with 0.05 or 0.1 per cent w/v chlorhexidine gluconate (CHX) continuously in their drinking water, which was well-tolerated. Compared to infected but untreated controls, their caries scores were less by 84 and 97 per cent respectively after 42 days. Coronal dental plaque deposits were reduced in a dose-related fashion. Culture plates of oral swabs showed reductions in Strep. sobrinus and total streptococci after 10 and 35 days of CHX. Hamster oral streptococci were more sensitive to CHX than were lactobacilli but neither was completely eliminated. The incidence of stained tooth deposits after 0.1 per cent CHX was slightly but not significantly greater than in controls.

Animals↗
PubMed1986

Status of a group of spina bifida children not managed by early surgery.

At Our Lady's Hospital for Sick Children, Crumlin, the policy towards neonates with Spina Bifida is one of individualised care. This means that those children who, experience has shown, will not be long term survivors are not subjected to procedures that are distressing and traumatic to the infant and parents. They are given full nursery care. A small number of children treated on this basis thrive. The question arises whether or not they have been further handicapped by this approach. Since this is a problem which causes concern to both parents and clinicians, this study reviews the present state of these survivors. In the five year period 1979-1983, there was a total of 192 infants admitted to Our Lady's Hospital with open myelomeningocoele. 66 were treated with early surgical intervention. 75 died without any surgical procedure at a mean of 46 days. 51 children underwent late intervention, despite which 29 died. A group of 22 are alive, aged 3-7 years. The mean first admission of these 22 patients was 77 days and was uneventful. However, all 22 are severely handicapped; all are paraplegic, doubly incontinent and have some degree of mental handicap. All have hydrocephalus graded moderate to gross and 17 have been shunted. Amongst these 22 surviving patients, we have been unable to identify, in the initial period, specific events or developments which have clearly caused additional damage to the infant's intellectual or physical well-being.

Cerebrospinal Fluid Shunts↗
PubMed1986

Should the tradition of right cerebral hemisphere shunting still prevail?

A review of the literature suggests that the right hemisphere compared with the left may be more sensitive to, and take longer to recover from, cerebral trauma. As there are also grounds for suggesting that shunting may be associated with limited cerebral insult, it is possible to conclude that, theoretically, left hemisphere shunting may be a preferable policy.

Cerebral Cortex↗
PubMed1986

Comparison of extracellular protein profiles of seven serotypes of mutans streptococci grown under controlled conditions.

Extracellular proteins produced by the four human commensal species of mutans streptococci were analysed. The organisms used were Streptococcus mutans, serotypes c, e and f, Streptococcus cricetus, serotype a, Streptococcus rattus, serotype b, and Streptococcus sobrinus, serotypes d and g. They were grown in continuous culture at different generation times and pH values in media containing either glucose or fructose to determine the extent of variation in extracellular protein production that could occur for an individual strain. The results for different organisms grown under the same conditions were then compared. The total amount of protein of molecular mass greater than or equal to 60 kDa varied considerably with the growth conditions and with the strain. Generally more protein was present at a higher pH, conditions under which the organisms also form more lipoteichoic acid. With respect to individual protein components SDS-PAGE proved better than isoelectric focusing for detecting phenotypic responses by a particular strain to environmental changes and differences between the different strains. Differences in the molecular masses of protein components were particularly pronounced in the regions designated P1 (185-200 kDa), P2 (130-155 kDa) and P3 (60-95 kDa). Every strain produced at least one component in the P1 region that cross-reacted with antiserum to the purified protein from S. mutans serotype c, a protein which is indistinguishable from antigens B and I/II. Two components in the P2 region were dominant in the case of S. cricetus and S. sobrinus strains and showed glucosyltransferase (GTF) activity. GTF activity was also detected in the P3 region, particularly with S. mutans strains.

Bacterial Proteins↗
PubMed1986

Immunological cross-reactivity of anionic proteins from caries-free and caries-active salivas which differ in biological properties toward oral streptococci.

We examined whether the anionic antimicrobial proteins in the saliva of certain caries-free (CF) individuals are immunologically cross-reactive with proteins in caries-active (CA) saliva which display identical isoelectric points but which exhibit growth-supportive properties for the oral streptococci. In the immunoblotting experiments reported here, the proteins present in CF and CA whole salivas reacted similarly with an antiserum prepared against the anionic inhibitory proteins. This antiserum also showed identical reactivity with the purified protein fraction containing the anionic proteins of interest from whole saliva of either CF or CA subjects. Additionally, an antiserum to CA saliva was found to react with the CF anionic inhibitory proteins. The fact that the inhibitory and noninhibitory proteins react similarly with the antisera used provides further evidence for similarity between both classes of proteins.

Adult↗