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Biomedical subjects

R J Fitzgerald

Publications and source records attributed to R J Fitzgerald.

At least 19 recordsLinked to original sources

Post traumatic intra-abdominal pseudo-aneurysms in children.

Pseudoaneurysms are uncommon following blunt abdominal trauma. A review of the literature has shown that such cases are usually managed aggressively. We report our experience of two cases of post traumatic intra-abdominal pseudoaneurysms which were managed conservatively.

Abdominal Injuries↗

Abdominopelvic mesh compartmentalization reduces the complications of radiotherapy in children: a preliminary report.

AIM: The aim of this report was to assess the effects of radiotherapy (RT) in children with abdominopelvic tumours in whom a biodegradable (Polyglactin 910) mesh had been inserted prior to commencement of radiotherapy. METHODS: Retrospective analysis was carried out of four patients with abdominopelvic tumours who underwent radiotherapy between 2000 and 2002 as part of their management. RESULTS: All children tolerated radiotherapy well with no evidence of acute or chronic radiation enteritis. One child developed prolonged postoperative ileus and a second child developed infective diarrhoea and fever, not related to radiation. CONCLUSION: We have highlighted a good tolerance of radiotherapy in children following the insertion of a Polyglactin 910 mesh prior to starting radiation and would recommend further larger studies with longer follow-up to support this.

Abdominal Neoplasms↗

Proteolytic enzyme activities in Cheddar cheese juice made using lactococcal starters of differing autolytic properties.

AIMS: To determine proteolytic enzyme activities released in Cheddar cheese juice manufactured using lactococcal starter strains of differing autolytic properties. METHODS AND RESULTS: The activities of residual chymosin, cell envelope proteinase and a range of intracellular proteolytic enzymes were determined during the first 70 days of ripening when starter lactococci predominate the microbial flora. In general, in cell free extracts (CFE) of the strains, the majority of proteolytic activities was highest for Lactococcus lactis HP, intermediate for L. lactis AM2 and lowest for L. lactis 303. However, in cheese juice, as ripening progressed, released proteolytic activities were highest for the highly autolytic strain L. lactis AM2, intermediate for L. lactis 303 and lowest for L. lactis HP. CONCLUSIONS: These results indicate that strain related differences in autolysis influence proteolytic enzyme activities released into Cheddar cheese during ripening. No correlation was found between proteolytic potential of the starter strains measured in CFE prior to cheese manufacture and levels of activities released in cheese juice. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings further support the importance of autolysis of lactococcal starters in determining the levels of proteolytic activities present in cheese during initial stages of ripening.

Cheese↗

Cheddar cheese cooking temperature induces differential lactococcal cell permeabilization and autolytic responses as detected by flow cytometry: implications for intracellular enzyme accessibility.

AIMS: To determine the influence of cheese cooking temperature on autolysis and permeabilization of two lactococcal starter strains in broth and in Cheddar cheese juice during ripening. METHODS AND RESULTS: Flow cytometry (FCM) was used to identify and enumerate intact and permeabilized cells in broth and in Cheddar cheese juice. Levels of intracellular enzyme activities were quantified concurrently. Permeabilized cell numbers increased for both strains in broth following a temperature shift from 32 to 38 degrees C and was accompanied by an increase in the level of accessible intracellular enzyme activities. The relative proportions of intact and permeabilized cell populations, as detected by FCM in cheese juice, changed during 42-day ripening. Permeabilized cell populations increased during ripening for both strains; however, an increase in accessible intracellular enzyme activity was observed only for the highly autolytic strain Lactococcus lactis AM2. CONCLUSIONS: Differences in the autolytic and permeabilization response induced by cooking temperature in two lactococcal strains affects intracellular enzyme accessibility in Cheddar cheese. SIGNIFICANCE AND IMPACT OF THE STUDY: This study highlights the importance of the autolytic and permeabilization properties of lactic acid bacteria starter strains and their impact on cheese ripening.

Bacteriolysis↗

Gastric stromal tumors in children.

Gastrointestinal stromal tumors (GIST) in children are rare and their behavior has been regarded as difficult to predict on pathological criteria. We report our experience with two gastric GISTs in children aged 10 and 11 years. Both remain alive and free of disease at 5 years and 2 years respectively. Comparison of the pathological features in the resected specimens with a recently proposed guidelines for predicting outcome in this group of tumors is reported.

Antigens, Neoplasm↗

In vitro generation and stability of the lactokinin beta-lactoglobulin fragment (142-148).

The objectives of this study were to investigate the generation of beta-lactoglobulin fragment (142-148) (beta-LG f(142-148) during the hydrolysis of whey proteins, and the in vitro stability of this fragment upon incubation with gastrointestinal and serum proteinases and peptidases. An enzyme immunoassay (EIA) protocol was developed for the quantification of beta-LG f(142-148) in whey protein hydrolysates and in human blood serum. The minimum detection limit was 3 ng/mL. The level of the peptide in whey protein hydrolysates was influenced by the degree of hydrolysis (DH). As expected, highest levels of this peptide were found in hydrolysates generated with trypsin. Sequential incubation of hydrolysates at different DH values with pepsin and Corolase PP, to simulate gastrointestinal digestion, generally resulted in the degradation of beta-LG f(142-148) as determined by EIA. Reversed-phase HPLC and angiotensin-I-converting enzyme (ACE) activity assays demonstrated that synthetic beta-LG f(142-148) was rapidly degraded upon incubation with human serum. Furthermore, beta-LG f(142-148) could not be detected by EIA in the sera of 2 human volunteers following its oral ingestion or in sera from these volunteers subsequently spiked with beta-LG f(142-148). These in vitro results indicate that beta-LG f(142-148) is probably not sufficiently stable to gastrointestinal and serum proteinases and peptidases to act as an hypotensive agent in humans following oral ingestion. The in vitro methodology described herein has general application in evaluating the hypotensive potential of food protein-derived ACE inhibitory peptides.

Angiotensin-Converting Enzyme Inhibitors↗

Translevator anal anomalies with cutaneous fistulae passing deep to the scrotum.

METHODS: The authors present a series of 9 patients collected from 4 centers with translevator anal anomalies, each of which has a fistula tracking forward deep to the scrotum and opening at the peno-scrotal junction. Whereas some would appear to be covered ani in type, others are deeper and would appear to fit in with an intermediate type of classification emphasizing the idea of a "spectrum" of malformation. RESULTS: The anatomic arrangement, associated anomalies (eg, 2 had hypospadias), and surgical management is described briefly in each case. Careful examination may be necessary to identify the fistula. CONCLUSIONS: It is recommended that the surgery be individualized depending on the findings. On a theoretical embryologic basis there is abnormality in the formation of the outer genital folds, and there also may be abnormality in some cases of the inner genital folds.

Abnormalities, Multiple↗

Twelve-year experience in the investigation and treatment of paragangliomas.

We report a 12-year laboratory experience in the diagnosis of 37 patients with phaeochromocytoma, one with malignant paraganglioma and one with ganglioneuroblastoma. Surgery was performed in eight different hospitals, which underlines the difficulty of ensuring uniformity of investigations. Of the 37 with phaeochromocytoma, 15 were in the right adrenal gland, 12 were on the left, seven were bilateral and three were extra adrenal. Twenty-three were male and 15 were female; the median age was 36 years. Four of five patients with von Hippel-Lindau disease had bilateral adrenal tumours and four had neurofibromatosis. None had multiple endocrine neoplasia. Using essential hypertensive patients as a reference population, diagnostic sensitivity was 80% for noradrenaline, 54.4% for adrenaline, 19.1% for dopamine, 93.3% for total normetanephrine, 33.3% for total metanephrine, 78.7% for 3-methoxy-4-hydroxymandelic acid (HMMA) and 23.5% for homovanillic acid (HVA). However, if each patient's results were taken as a package, the sensitivities were 100% for noradrenaline, 63.6% for adrenaline, 30.3% for dopamine and 89% for HMMA. Seven recent patients had gene analysis. There were six (15.4%) deaths due directly or indirectly to the paraganglioma. Postoperative blood pressures were normal in 74%. The decrement in catecholamine values post-surgery is shown. Urinary noradrenaline values fell by a mean of 94.5% and the use of urinary noradrenaline as a tumour marker is also demonstrated.

Adrenal Gland Neoplasms↗

Prophylactic thyroidectomy in the treatment of thyroid medullary carcinoma. Age for surgery?

Since the association of RET proto-oncogene mutations and medullary thyroid carcinoma in children there has been much discussion regarding timing of surgery. Our study group was formed from a brother and sister (8 and 5) and 3 brothers (9, 13, 16) selected on the basis of a positive family history for thyroid medullary carcinoma. Histological examinations of the thyroidectomy specimens showed that the 8- and 9-year old had microinvasive carcinoma and the remaining three had C-cell hyperplasia. Our recommendation is for prophylactic thyroidectomy for children with RET proto oncogene mutations at an early age, clearly before age 5.

Adolescent↗

Catecholamine secretion and ploidy in phaeochromocytoma.

The aim was to evaluate 24 hr urine catecholamine, HMMA and HVA excretion in relation to ploidy in phaeochromocytoma. Data from five diploid and nine tetraploid tumours showed a significant reduction in urine noradrenaline (p = 0.02) and HMMA (p = 0.03) in diploid tumours but no difference in adrenaline, dopamine and HVA excretion using the Mann-Whitney U test. None of the patients showed recurrence after a mean of 5.7 years of follow up. A review of published ploidy studies in phaeochromocytoma shows that malignancy is more than six times more common in non-diploid tumours but diploidy does not equate with benignity. No biochemical marker is a reliable index of malignancy. All patients should undergo lifetime review for recurrence.

Adrenal Gland Neoplasms↗

Purification and characterization of a lysine-p-nitroanilide hydrolase, a broad specificity aminopeptidase, from the cytoplasm of Lactococcus lactis subsp. cremoris AM2.

A hydrolase activity that cleaves lysyl-p-nitroanilide (Lys-pNA) has been purified from the cytoplasm of Lactococcus lactis subsp. cremoris AM2 by chromatography on DE52, DEAE Affi-Gel Blue Gel, Hydroxyapatite Bio-Gel HTP and Phenyl Sepharose. The purified aminopeptidase was found to have a native M(r) of 50,000-55,000 by gel filtration chromatography and by FPLC gel filtration on Superose 12 and to be composed of a single polypeptide chain following SDS-PAGE. Enzyme activity was almost completely inhibited by EDTA, amastatin, puromycin and bestatin, while the sulphydryl-reactive agents p-chloromercuribenzoate and iodoacetamide were inhibitory. The enzyme was found to be very unstable during the purification procedures at 4 degrees C and its stability was greatly improved when 10 ml glycerol/l and 2 mM-dithiothreitol were included in the purification buffers. The purified enzyme was found to hydrolyse a wide range of dipeptides, tripeptides and longer peptides provided that proline was not present in the penultimate position from the N-terminus or that a pyroglutamyl residue was not present at the N-terminus. While neither Asp-pNA nor Pro-pNA was hydrolysed by the purified enzyme, the release of N-terminal acidic residues from peptides was observed in addition to the release of N-terminal proline from Pro-Leu-Gly-NH2, Pro-Leu-Gly-Gly and Pro-His-Pro-Phe-His-Leu-Phe-Val-Tyr. This ability of Lys-pNA hydrolase to release N-terminal proline residues was employed in concert with a purified aminopeptidase P preparation to release alternate N-terminal amino acids from Tyr-Pro-Phe-Pro-Gly. The complementary action of these enzymes represents an alternative mechanism to that of post-proline dipeptidyl aminopeptidase for metabolism of proline-containing peptides.

Amino Acid Sequence↗

Pelvic distraction to improve exposure in radical surgery for pelvic tumours in children.

We describe one patient who had pubic osteotomy and three who had symphysiotomy as an aid to radical tumour resections over the last 7 years. In each it was possible to distract the pelvis so improving access to the tumour. All four patients had pelvic rhabdomyosarcomata, three primarily in the prostate and lower bladder and one was a large tumour filling the pelvis, probably of bladder origin. No immediate or long-term complications of the procedure occurred, and in the two patients who died (2.5 years and 1 year post-surgery) or in the two survivors.

Child, Preschool↗

The Dandy-Walker syndrome--a 10-year experience of its management and outcome.

Hydroephalus of childhood may be associated with intracranial haemorrhage, infection, aqueductal stenosis, Arnold-Chiari malformation (spina bifida), tumours or more uncommonly with the Dandy-Walker syndrome (DWS). We present our experience with the management of this condition over a 10-year period. Twelve children with a definite diagnosis of DWS are reviewed with regard to the age at diagnosis, investigations, treatment, associated problems and overall outcome. Two patients died; there was a high incidence of mental retardation (65%) and associated problems. All but one child had ventriculo-peritoneal shunting and two had cysto-peritoneal shunts in addition to their V-P shunts. There were no familial cases; one child had a chromosomal abnormality. Although the long-term outcome is dismal in most cases, about 35% of the children have a reasonable outcome and hence the condition warrants energetic treatment.

Child↗

Scarring following renal trauma in children.

OBJECTIVE: To assess factors relating to renal scarring following kidney injury. PATIENTS AND METHODS: A total of 25 children who had documented renal injury between 1981 and 1988 were included in the study and 19 were followed up for 1 month to 12 years (mean 5.5 years) and the development of hypertension and renal scars assessed using ultrasonography and radionuclide scans (dimercapto-succinic acid, DMSA). RESULTS: Of the 19 children 13 had renal contusions, four had renal lacerations and two sustained severe renal injury, one of whom had pelvi-ureteric disruption. Eighteen patients presented with macroscopic or microscopic haematuria except the patient with pelvi-ureteric junction disruption who presented 3 weeks later with abdominal distension, vomiting and hypertension. All the patients were managed without an operation except the latter patient who required nephrectomy. Renal scarring was demonstrated in four children at a mean follow-up of 3.5 years, one following renal contusion (5% scarring), two after renal laceration (50% scarring) and one after rupture of the kidney (100% scarring). In one patient intravenous pyelography did not reveal a renal scar but a radionuclide scan performed 5 years later demonstrated a scar. Transient hypertension was noted in only two patients but peripheral plasma renin levels were normal. CONCLUSION: Renal scars developed in four of 19 patients with renal trauma and more than half of the patients with severe renal injury. Long-term follow-up including a radionuclide scan is therefore necessary in patients with renal injury. Although no sustained hypertension was noted in any patients in this study, long-term blood pressure assessments would seem prudent.

Child↗

Varicocele and the horizontal testis: a change in position?

Horizontal lie of the testis has recently been observed in association with varicoceles in a pediatric population. Six children with a varicocele presented to the surgical department during a 6-month period. All had an associated horizontal lie of the testis. In two of these cases, high ligation of internal spermatic veins was performed, after which one reverted to a vertical position with resolution of the varicocele. Seven children who underwent high ligation of a varicocoele over a 5-year period were examined. All were found to have no evidence of the varicocele at follow-up. All but one had a vertical lie. Horizontal lie of the testis in children is a new clinical sign that should alert the examiner to the possibility of an underlying varicocele.

Adolescent↗

A microbiological study of recurrent dentinal caries.

A cross-sectional microbiological study of recurrent (secondary) dentinal caries was conducted. Freshly extracted human teeth containing amalgam restorations judged to be clinically intact were scrubbed with chlorhexidine soap and soaked in povidone-iodine solution. The teeth were then split to remove the fillings and examined for dentinal caries. Of 54 teeth examined, 22 (40%) were free of dentinal caries in the restored site. The remainder were assigned to arbitrary groups of questionable (15), initial (8) and active caries (9), based on the amount of dentinal decay observed. Comparison of pre-extraction bite-wing radiographs with the in situ findings revealed the sensitivity for secondary caries detection to be only about 50%. In contrast, the specificity for absence of caries was 73%. There was considerable variation in the numbers and types of micro-organisms found in dentine samples from lesions of comparable severity. Facultatively, anaerobic streptococci were the most numerous and most prevalent micro-organisms in the affected dentine, but no single species was significantly associated with recurrent caries. Mutans streptococci were found in 40% of sites with any degree of caries and in only 3 of the 9 sites with the most caries. Homofermentative lactobacilli were present in 18 of the 54 dentine samples, including 4 from caries-free sites. While the prevalence and numbers of lactobacilli increased with the degree of caries, they occurred in less than half of the affected dentine samples. Actinomyces occurred in 15 of 32 affected sites but only in 2 of the 9 most active sites. Their numbers never exceeded 3 x 10(3) CFU/mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomyces↗