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Biomedical subjects

D F Thomas

Publications and source records attributed to D F Thomas.

At least 19 recordsLinked to original sources
PubMed1992

Novel inhibitors of prolyl 4-hydroxylase. 2. 5-Amide substituted pyridine-2-carboxylic acids.

A series of 5-[(arylcarbonyl)amino]- and 5-(arylcarbamoyl)pyridine-2-carboxylic acids has been prepared and tested for activity as inhibitors of the enzyme prolyl 4-hydroxylase (EC 1.14.11.2). All the analogues prepared were inhibitors of the enzyme in vitro, the best compounds being equipotent with the known inhibitor pyridine-2,5-dicarboxylic acid (9). Like 9 these amidic analogues were not active in a cultured embryonic chick tendon cell model, considered to be a predictor of in vivo activity. The activity of the amides is not consistent with the model described for the mode of action of 9 with the enzyme and aspects of this are discussed.

Amides↗
PubMed1992

Use of 99mtechnetium-dimercaptosuccinic acid to study patterns of renal damage associated with prenatally detected vesicoureteral reflux.

Static isotope imaging with 99mtechnetium-dimercaptosuccinic acid was performed at a mean age of 34 days in 32 children (50 kidneys) whose vesicoureteral reflux had been identified as a result of prenatal ultrasound scanning. Three patterns of isotope uptake were observed: 1) noninfected primary vesicoureteral reflux (15 children, 24 kidneys), 2) noninfected secondary (obstructed) vesicoureteral reflux (9 patients, 11 kidneys) and 3) infected primary reflux (8 infants, 15 kidneys). In 20 pattern 1 kidneys (83%) renal morphology and differential isotope were normal. In the 4 kidneys (17%) that showed evidence of impaired function this took the form of global parenchymal loss, that is small kidneys rather than focal scarring. In pattern 2 the combination of fetal vesicoureteral reflux and obstruction was a potent cause of renal damage with total or near total loss of function in 7 of 9 refluxing units associated with posterior urethral valves and in 2 kidneys with secondary ureteropelvic junction obstruction. Appearances of focal scarring were confined in pattern 3 and were found in 4 kidneys (27%). This overall incidence of detectable renal damage was lower than expected. Even when infection occurs, prenatal diagnosis may lessen the risk of scarring by enabling treatment to be instituted promptly. The findings suggest that uncomplicated primary vesicoureteral reflux is a relatively benign insult to the fetal kidney and that reflux nephropathy found in children presenting clinically is the result of infected vesicoureteral reflux in postnatal life. Any comparison of published studies will prove difficult until there is a more standardized approach to imaging technique and patient selection.

Female↗
PubMed1991

Experience with the Fowler Stephens and microvascular procedures in the management of intraabdominal testes.

The Fowler Stephens operation and microvascular procedures were compared for the management of 23 intra-abdominal testes in 15 boys, 7 of whom had the prune belly syndrome. The Fowler Stephens operation was used for 15 testes (4 single-stage and 11 two-stage) and microvascular transfer was used for 8 testes. Eleven testes treated by the Fowler Stephens procedure (73%) and 7 treated by microvascular procedures (88%) were viable and intrascrotal after an average follow-up of 3.0 years, giving an overall success rate of 78%. Eight of 9 post-pubertal testes were biopsied. Severe maturational arrest was evident in all and carcinoma in situ was present in one.

Abdomen↗
PubMed1991

Antenatally detected pelviureteric junction obstruction. Is non-operation safe?

We report follow-up data (minimum of 1 year) on 63 kidneys with antenatally detected pelviureteric junction obstruction, as defined by renographic criteria. The condition was bilateral in 10 patients (i.e. 20 kidneys), 2 patients had unilateral obstruction with contralateral multicystic dysplastic kidneys, and 41 patients had unilateral obstruction with a normal contralateral kidney. In the latter group, 29 (71%) had good function (greater than 40%) at initial assessment. Of the 63 kidneys, 24 (38%) were operated upon following initial assessment, mainly for impaired function. Of 39 patients, initially managed non-operatively, 8 (21%) were operated upon subsequently: 3 for deteriorating function (2 of whom have been reassessed and both have regained their lost function) and 5 for other renographic or ultrasonic indications). Of the original 63 kidneys, 31 (49%) continue to be managed non-operatively; 16 of these (52%) show improving ultrasound appearances, 8 of 17 studied show improved drainage, and all unilateral cases have stable good function. It is concluded that non-operative management of selected cases of antenatally detected pelviureteric junction obstruction is safe.

Female↗
PubMed1990

Prenatally diagnosed reflux: a follow-up study.

This report analyses the characteristics and outcome of 25 infants with vesicoureteric reflux detected prenatally on the basis of dilatation of the fetal urinary tract. Sixteen infants had bilateral reflux--a total of 41 refluxing units. The high proportion of males (84%) contrasts with clinically presenting reflux, which is dominated by females. Prenatally diagnosed reflux is generally of a higher grade--usually grade IV. Eight children (32%) had coexistent congenital abnormalities. Chemoprophylaxis was completely effective in 17 children (68%), who remained infection-free; 3 children (12%) had a single urinary infection and were managed conservatively whilst 5 (20%) experienced 2 or more infections and required reimplantation or vesicostomy. Spontaneous cessation of reflux was observed in 6 (35%) of 17 refluxing ureters reassessed after a mean interval of 2.1 years. The significance of isotope findings was sometimes difficult to assess but results in 30 refluxing units support the concept that focal renal scarring is usually a consequence of infected reflux in postnatal life.

Female↗
PubMed1990

Fetal uropathy.

Explore the source record for details and available documents.

Female↗
PubMed1989

Bilateral fetal uropathy: what is the outlook?

OBJECTIVE: To assess the morbidity and mortality associated with a prenatal diagnosis of bilateral fetal uropathy. DESIGN: Retrospective study. SETTING: Departments of radiology, paediatric surgery, obstetrics, and pathology in two teaching hospitals that serve as referral centres for the Yorkshire region. PATIENTS: 126 Cases of fetal uropathy were referred either prenatally or postnatally from hospitals in Yorkshire between August 1982 and December 1987. The disease was bilateral in 54 cases and unilateral in 72 cases. In 14 cases bilateral fetal uropathy was associated with coexistent disease. INTERVENTIONS: All cases were managed individually by an obstetrician after discussion with the radiologists and paediatric surgeons. Babies who survived were treated prophylactically with antibiotics after delivery and were operated on if appropriate. END POINT: Assessment of prognosis for long term renal function for each baby referred between August 1982 and December 1987: follow up ranged from six months to five years. MEASUREMENTS AND MAIN RESULTS: Of the 54 fetuses with bilateral fetal uropathy, 13 were terminated as the prenatal findings of ultrasonography were considered to be incompatible with long term survival. Ten of the liveborn babies died, five of renal or pulmonary insufficiency, or both, and five of associated congenital anomalies. Thirty one infants survived to follow up; four of these had serious coexistent disease and two had impaired renal function. Thus the overall mortality was 43% and the morbidity rate 19%. The renal anomaly was associated with other serious disease in 14 cases (26%) compared with two (3%) of the 72 cases of unilateral fetal uropathy. All but two of the 27 infants with isolated bilateral urinary tract disease had excellent prospects for survival. CONCLUSION: Although bilateral fetal uropathy is associated with a high morbidity rate and mortality, careful prenatal assessment can help to identify fetuses with a poor prognosis. The outlook for a fetus with isolated renal disease if treated promptly after delivery is excellent and compares favourably with that reported after prenatal surgical intervention.

Abnormalities, Multiple↗
PubMed1989

Cloacal malformations: embryology, anatomy and principles of management.

The cloacal anomaly is characterised by the persistence of a common channel draining the urinary, genital and alimentary tracts via a single orifice. It results from abnormal compartmentalisation of features that are normal in the primitive female embryo. Abnormal embryology and cloacal anatomy are described in detail. Cloacal abnormalities are usually diagnosed promptly in the neonatal period. Management can be divided into three phases: (1) investigating and defining the anatomy, (2) neonatal intervention with relief of obstruction and (3) definitive surgical reconstruction. Successful management of the child with a cloacal abnormality remains one of the greatest challenges to the pediatric surgeon.

Cloaca↗
PubMed1988

Multicystic dysplastic kidney: is nephrectomy still appropriate?

We analyzed 25 cases of multicystic kidney to assess the impact of prenatal diagnosis on the management of this condition. The incidence of unilateral multicystic kidney was 1 in 4,300 live births. Of the 23 children with unilateral multicystic kidneys only 3 (13 per cent) had a readily palpable lesion. These findings suggest that multicystic kidney is a more common renal anomaly than was previously recognized and that the majority of cases remained undiagnosed before the advent of prenatal diagnosis. Ultrasound re-evaluation in 11 children suggests that the natural history of multicystic kidneys is towards spontaneous involution. Two kidneys were not identifiable by followup ultrasound. Hypertension and malignancy complicating multicystic kidney are reported infrequently. The literature on hypertension does not generally support the view that multicystic kidney poses a significant risk of hypertension in later childhood or adult life. We believe that the routine removal of multicystic kidneys in infancy is no longer appropriate.

Evaluation Studies as Topic↗
PubMed1988

Oral vancomycin in prevention of necrotising enterocolitis.

Eighty four very low birthweight babies (considered high risk for developing necrotising enterocolitis) were given vancomycin orally for 48 hours before introduction of oral feeds; one developed necrotising enterocolitis. One hundred and twenty very low birthweight babies (not considered such high risk) were fed without first receiving vancomycin; 17 developed necrotising enterocolitis. Although this was not a randomised control trial, results indicate a role for vancomycin in prophylaxis of necrotising enterocolitis.

Administration, Oral↗
PubMed1987

Percutaneous nephrostomy in paediatrics.

Percutaneous nephrostomy has been performed on 18 kidneys in 16 children with an age range of 1 day old to 14 years. The indications and techniques for percutaneous nephrostomy are described, the results are documented, and the effects of the procedure on the management of these patients are discussed. It is shown that percutaneous nephrostomy in paediatrics is a safe and reliable method for draining renal collecting systems in order to relieve obstruction, to assess renal function and to drain pyonephroses.

Child↗
PubMed1986

Enterocolitis in Hirschsprung's disease: a controlled study of the etiologic role of Clostridium difficile.

Cytopathic toxin neutralized by Clostridium sordellii antiserum was found in the feces of seven out of 13 children with Hirschsprung's disease complicated by enterocolitis (54%). Clostridium difficile was isolated from ten of these 13 children (77%). The frequency of fecal toxin positivity, the magnitude of toxin titers, and the isolation rate of C difficile were all significantly greater in children with Hirschsprung's enterocolitis than in children whose Hirschsprung's disease was not complicated by enterocolitis or in children without Hirschsprung's disease. It is suggested that C difficile may be causally related to enterocolitis in Hirschsprung's disease, but the age distribution of positive results indicates that the major etiologic role is confined to children under three years of age. Vancomycin was found to be an effective form of treatment in the children with enterocolitis in whom it was employed.

Bacteriological Techniques↗
PubMed1986

Pseudomembranous colitis in children and adults.

Pseudomembranous colitis remains a potentially lethal complication of antibiotic usage. Identification of Clostridium difficile as the major pathogen has led to a rational successful approach to therapy and has widened the spectrum of associated disease. The frequent asymptomatic colonization of healthy neonates by C. difficile remains an enigma.

Adult↗