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Biomedical subjects

D T Cass

Publications and source records attributed to D T Cass.

At least 37 records · Page 2Linked to original sources
PubMed2000

Clinical review of the 'Snodgrass' hypospadias repair.

BACKGROUND: Snodgrass first described the tubularized, incised plate (TIP) urethroplasty for distal hypospadias repair in 1994 based on the concept of hingeing the incised urethral plate. The use of this technique allows a vertically orientated glanular meatus to be produced. A retrospective review of patients who had this procedure for the primary repair of distal hypospadias at New Children's Hospital was performed to objectively assess the cosmetic and functional outcomes of this technique. METHODS: All patients having a TIP urethroplasty for the primary repair of distal hypospadias between 1996 and 1998 were requested to attend for review in an independent clinic. The parents were interviewed and the patient was examined to determine meatal location, meatal size, glanular configuration, urinary stream, straightness of erections, cosmesis, and the presence or absence of cutaneous sinus tracts or a urethral fistula. RESULTS: Sixty patients were identified. Forty-nine were reviewed in person, 10 were reviewed by telephone and one could not be traced. The median age at surgery was 13 months (range: 6-144 months), with a median follow up of 27 months (range: 2-33 months). A glanular meatus was achieved in 57 patients (97%) and a conical glanular configuration was achieved in 58 patients (98%). The urinary stream and erections were straight in 54 (89%) and 58 patients (98%), respectively. Suture sinus tracts were present in 14 (24%) patients. Six patients (10%) developed a urethral fistula and three (5%) developed meatal stenosis. A good or satisfactory final cosmetic and functional result was achieved in 58 patients (98%). CONCLUSIONS: The results of TIP urethroplasty are satisfactory at New Children's Hospital with the benefit of a cosmetic final outcome similar to a circumcised penis.

Child↗
PubMed2000

Small bowel injuries in children.

OBJECTIVE: To determine the common features of small bowel injury (SBI) in childhood and the consequences of delayed diagnosis. METHODOLOGY: A retrospective case review was performed of children with traumatic SBI between January 1988 and November 1999. RESULTS: Twenty-eight patients were identified with SBI. Road trauma accounted for 71% of them. Tachycardia was present on admission in 82% of patients with SBI including all but one of the intestinal perforations. SBI was associated with a Chance fracture of the lumbar spine in three patients (11%). An abdominal computed tomography scan with intravenous contrast was abnormal in all patients with a perforation or mesenteric tear. Diagnosis was delayed in six patients, one of whom died as a result of sepsis from a small bowel perforation. CONCLUSIONS: Persistent tachycardia with an appropriate mechanism of injury following blunt abdominal trauma requires active exclusion of SBI. Delayed diagnosis is associated with significant morbidity and mortality.

Adolescent↗
PubMed1999

Dose response relationship between adriamycin and birth defects in a rat model of VATER association.

BACKGROUND/PURPOSE: The aim of this study was to reproduce the animal model of esophageal atresia and the VATER association. The purpose was a dose response analysis of Adriamycin teratogenicity in the rat and comparison of these anomalies with the human VATER association. METHODS: Twenty time-mated Sprague-Dawley rats received intraperitoneal Adriamycin (dose range, 0 to 2.5 mg/kg/d) for 4 consecutive gestational days E6 to E9. The embryos were harvested on day E21, inspected, weighed, and dissected with a binocular dissecting microscope. Statistical analysis was performed with exact chi2. RESULTS: Threshold doses of 1.25 and 1.5 mg/kg/d Adriamycin produced renal and gastrointestinal anomalies, respectively (exact chi2, P < .00001). In doses below 1.25 mg/kg/d Adriamycin, no anomalies were seen, and in above-threshold doses, the frequency of anomalies rose sharply as the dose increased. At 2.25 mg/kg/d of Adriamycin all embryos were abnormal, and Adriamycin at 2.5 mg/kg/d led to resorption of all embryos. CONCLUSIONS: Adriamycin induced esophageal atresia, and VATER in the rat is a reproducible model that has many similarities to the VATER anomalies in the human. There is a relationship between dose and the frequency as well as severity of anomalies. Further studies of this model are likely to provide information relevant to the understanding of this human congenital disease.

Abnormalities, Drug-Induced↗
PubMed1999

Children at play: the death and injury pattern in New South Wales, Australia, July 1990-June 1994.

OBJECTIVES: To describe and to understand the pattern of play-related deaths and injury (excluding organized sports) among children in New South Wales (NSW), Australia. METHODOLOGY: This study utilized a state-wide prospective surveillance data collection of paediatric traumatic deaths and injuries at the Royal Alexandra Hospital for Children. Deaths and injury cases were selected from the NSW Trauma Death Registry and Childsafe NSW database. Information including basic demographics, the surrounding circumstances of death and injury incidents, and the required treatment was collected. RESULTS: There were 30 play-related deaths and 92 drownings over the 4-year period. The male to female ratio was about 2:1. Excluding drowning, which has been reported elsewhere, and sports, the leading causes of play-related deaths were burns (eight) and asphyxiation (eight). An average of 6444 presentations to the emergency departments per year were recorded with sex ratio and age distribution pattern similar to the deaths. The home was the most common place (55.5%) of play-related injury, specifically the living and sleeping area. Falls, both under and above 1 metre, were the most common causes of injury (50.9%). The leading mechanism was cuts and lacerations (21.2%). Nearly one-third (32.7%) of all injuries were to the head, with face, cheek, forehead and scalp as the most common injured body part. Significant associations between place of injury, injured body parts and age were observed. CONCLUSIONS: Play-related injury is common among children, and in some cases causes severe injury and death. To tackle the problem of play-related deaths and injuries, a holistic approach is suggested. This includes the provision of a safe environment, supervision by parents, education of children and detailed data collection.

Accident Prevention↗
PubMed1998

Congenital central hypoventilation syndrome and Hirschsprung's disease.

Five cases of the Hirschsprung's disease-congenital central hypoventilation syndrome (CCHS) association are presented and 41 other published cases reviewed. These children have a distinct pattern of associated features, an equal sex incidence, and a characteristic spectrum of disease severity which suggests that the condition is genetically distinct from other cases of Hirschsprung's disease. While approximately 1.5% of Hirschsprung's disease patients, and 10% of those with total colonic aganglionosis, will have CCHS, up to 50% of CCHS patients will have Hirschsprung's disease. Approximately 20% of CCHS/Hirschsprung patients will also have neuroblastoma or ganglioneuroma, usually multiple. Abnormalities of the eye and autonomic nervous system are also common. The ventilatory abnormality is usually evident on the first day of life. The aganglionosis is also severe, with more than half (59%) of the patients having aganglionosis extending into the small bowel.

Deglutition Disorders↗
PubMed1998

Hirschsprung disease, microcephaly, mental retardation, and characteristic facial features: delineation of a new syndrome and identification of a locus at chromosome 2q22-q23.

We have identified six children with a distinctive facial phenotype in association with mental retardation (MR), microcephaly, and short stature, four of whom presented with Hirschsprung (HSCR) disease in the neonatal period. HSCR was diagnosed in a further child at the age of 3 years after investigation for severe chronic constipation and another child, identified as sharing the same facial phenotype, had chronic constipation, but did not have HSCR. One of our patients has an interstitial deletion of chromosome 2, del(2)(q21q23). These children strongly resemble the patient reported by Lurie et al with HSCR and dysmorphic features associated with del(2)(q22q23). All patients have been isolated cases, suggesting a contiguous gene syndrome or a dominant single gene disorder involving a locus for HSCR located at 2q22-q23. Review of published reports suggests that there is significant phenotypic and genetic heterogeneity within the group of patients with HSCR, MR, and microcephaly. In particular, our patients appear to have a separate disorder from Goldberg-Shprintzen syndrome, for which autosomal recessive inheritance has been proposed because of sib recurrence and consanguinity in some families.

Abnormalities, Multiple↗
PubMed1997

Frequency of RET mutations in long- and short-segment Hirschsprung disease.

Hirschsprung disease, or congenital aganglionic megacolon, is a genetic disorder of neural crest development affecting 1:5,000 newborns. Mutations in the RET proto-oncogene, repeatedly identified in the heterozygous state in both long- and short-segment Hirschsprung patients, lead to loss of both transforming and differentiating capacities of the activated RET through a dominant negative effect when expressed in appropriate cellular systems. The approach of single-strand conformational polymorphism analysis established for all the 20 exons of the RET proto-oncogene, and previously used to screen for point mutations in Hirschsprung patients allowed us to identify seven additional mutations among 39 sporadic and familial cases of Hirschsprung disease (detection rate 18%). This relatively low efficiency in detecting mutations of RET in Hirschsprung patients cannot be accounted by the hypothesis of genetic heterogeneity, which is not supported by the results of linkage analysis in the pedigrees analyzed so far. Almost 74% of the point mutations in our series, as well as in other patient series, were identified among long segment patients, who represented only 25% of our patient population. The finding of a C620R substitution in a patient affected with total colonic aganglionosis confirms the involvement of this mutation in the pathogenesis of different phenotypes (i.e., medullary thyroid carcinoma and Hirschsprung). Finally the R313Q mutation identified for the first time in homozygosity in a child born of consanguineous parents is associated with the most severe Hirschsprung phenotype (total colonic aganglionosis with small bowel involvement).

DNA Mutational Analysis↗
PubMed1997

Hirschsprung's disease, colonic atresia, and absent hand: a new triad.

Colonic atresia (CA) has been reported in association with Hirschsprung's Disease (HSCR) on 11 previous occasions. In most reported cases the atresia has involved the right side of the colon; but in this, the twelfth case report, the atresia involved the left side of the colon, with aganglionosis of the entire distal gut. In addition, the child had an absent hand. The authors believe that this triad has not been reported previously. The literature is reviewed, and possible mechanisms are discussed.

Abnormalities, Multiple↗
PubMed1996

School bus related deaths and injuries in New South Wales.

OBJECTIVE: To report the circumstances of paediatric bus related deaths and injuries in New South Wales (NSW) to identify preventable factors. DESIGN: Retrospective survey using two surveillance systems-the NSW Paediatric Death Review Database and the Childsafe Injury Surveillance System. PATIENTS: Children (0-14 years of age) who died or were injured as a result of a school bus related incident. RESULTS: Twenty-two deaths and 58 injuries were recorded. Three of the children who died were passengers (two deaths were due to errant behaviour), two were alighting from the bus (bus door entrapment) and 17 (77%) were pedestrians crossing the road before or as the bus departed. The major causes of death were head injury and blood loss. Seventeen of the injured children were pedestrians and most (82%) of these sustained serious injury requiring admission to hospital. CONCLUSIONS: The greatest risk to schoolchildren from bus related injuries was as pedestrians after alighting from a bus, especially when moving behind the bus. Preventable factors include slowing of traffic (40 kph) near stationary school buses, and parents waiting on the side of the road where the child alights from the bus. Continuing road safety education remains important for schoolchildren and parents as well as for drivers.

Accidents, Traffic↗
PubMed1996

Null mutation of endothelin receptor type B gene in spotting lethal rats causes aganglionic megacolon and white coat color.

Mutations in the gene encoding the endothelin receptor type B (EDNRB) produce congenital aganglionic megacolon and pigment abnormalities in mice and humans. Here we report a naturally occurring null mutation of the EDNRB gene in spotting lethal (sl) rats, which exhibit aganglionic megacolon associated with white coat color. We found a 301-bp deletion spanning the exon 1-intron 1 junction of the EDNRB gene in sl rats. A restriction fragment length polymorphism caused by this deletion perfectly cosegregates with the sl phenotype. The deletion leads to production of an aberrantly spliced EDNRB mRNA that lacks the coding sequence for the first and second putative transmembrane domains of the G-protein-coupled receptor. Radioligand binding assays revealed undetectable levels of functional EDNRB in tissues from homozygous sl/sl rats. We conclude that EDNRB plays an essential role in the normal development of two neural crest-derived cell lineages, epidermal melanocytes and enteric neurons, in three mammalian species--humans, mice, and rats. The EDNRB-deficient rat may also prove valuable in defining the postnatal physiologic role of this receptor.

Amino Acid Sequence↗
PubMed1996

Changing patterns of diagnosis and treatment of infantile hypertrophic pyloric stenosis: a clinical audit of 303 patients.

This review of 303 patients with infantile hypertrophic pyloric stenosis (IHPS) concentrates on the influence of clinical audit on diagnosis, complications, and factors contributing to hospital stay. Although the audit has enabled improvement in care by pediatric surgeons, there has been less change in areas controlled by other specialities. During a 12-year period, the number of patients diagnosed solely by clinical examination decreased from 74% to 28%, and the use of diagnostic tests increased (ultrasonography from 16% to 65% and barium meal from 12% to 28%). This trend continued throughout the series despite a review after 8.5 years, which recommended fewer tests. Although there may be some benefit from earlier confirmation of IHPS (the percentage of patients with a serum chloride value of less than 85 mmol/L decreased from 26% to 15%), the need for diagnostic tests could be reduced by expectant management. Better improvement occurred with surgical complications; the incidence of mucosal perforation decreased from 7 of 151 (4.6%) in the first 6 years to 0 of 152 in the last 6 years, and wound dehiscence was reduced from 3 to 0. The wound infection rate decreased from 9% to 4%, but had fluctuations. The average length of stay was reduced from 3.7 to 3.2 days. Further reductions in hospital stay will depend on earlier operation for patients with normal electrolyte values at the time of admission (61%) and a preparedness to confidently discharge patients even if there is vomiting. From the data available, early operation on the day of admission and discharge the next day would be a reasonable strategy for the majority of patients whose admission electrolyte values are normal. Complications such as mucosal perforation and wound dehiscence should be rare. This is not to suggest that IHPS is a condition of minor consequence; the surgeon must be skilled and care meticulous. If electrolytes are disturbed at the time of operation or if unrecognized mucosal perforation occurs, what should be an uneventful illness can result in disaster.

Age Factors↗
PubMed1995

Interstitial deletion of the endothelin-B receptor gene in the spotting lethal (sl) rat.

The autosomal recessive spotting lethal (sl) rat phenotype is characterized by absence of intramural ganglion cells in the entire colon and distal small bowel, thus resembling the human Hirschsprung (HSCR) disease. A strategy for identifying the gene responsible for this rat defect was initiated by backcrossing DA x sl rats. After excluding linkage with two candidate genes, RET and Endothelin-3 (EDN3), a highly significant lod score (Z = 47.05 at theta = 0) was found between the Endothelin-B Receptor (EDNRB) gene and the sl phenotype. The exon-intron structure of this rat gene was reconstructed and each exon of the sl rat was screened for possible mutations. A 301 bp interstitial deletion, encompassing the distal half of the first coding exon (exon 2) and the proximal part of the adjacent intron, was demonstrated. This deletion results in two transcriptional products, 270 and 238 bp shorter than wild type cDNA. The discovery of the molecular defect underlying the sl rat phenotype should contribute to the understanding of the genetic heterogeneity of HSCR in man.

Animals↗
PubMed1995

Mutation analysis of the RET receptor tyrosine kinase in Hirschsprung disease.

Hirschsprung disease (HSCR), or congenital aganglionic megacolon, is the most common cause of congenital bowel obstruction with an incidence of 1 in 5000 live births. Recently, linkage of an incompletely penetrant, dominant form of HSCR was reported, followed by identification of mutations in the RET receptor tyrosine kinase. To determine the frequency of RET mutations in HSCR and correlate genotype with phenotype, we have screened for mutations among 80 HSCR probands representing a wide range of phenotypes and family structures. Polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) analysis of RET's 20 exons for mutations among probands revealed eight putative mutations (10%). Sequence changes, which included missense, frameshift and complex mutations, were detected in both familial and isolated cases, among patients with both long- and short-segment HSCR and in three kindreds with other phenotypes (maternal deafness, talipes and malrotation of the gut, respectively). Two mutations (C609Y and C620R) we identified have previously been associated with multiple endocrine neoplasia type 2A (MEN2A), medullary thyroid carcinoma (MTC) and, on rare occasions, HSCR. Thus, while HSCR family members may be at risk for developing neuroendocrine tumors, it follows that identical mutations in RET may be able to participate in the pathogenesis of distinct phenotypes. Our data suggest that: (i) the overall frequency of RET mutations in HSCR patients is low and therefore, other genetic and/or environmental determinants contribute to the majority of HSCR susceptibility, and (ii) at present, there is no obvious relationship between RET genotype and HSCR phenotype.

Base Sequence↗
PubMed1994

Postnatal diagnosis and outcome of urinary tract abnormalities detected by antenatal ultrasound.

OBJECTIVES: To determine the incidence of urinary tract abnormalities detected by antenatal ultrasound; the value of fetal renal measurements in predicting significant uropathy; and the nature and clinical outcome of fetal uropathy. DESIGN AND SETTING: A retrospective analysis of babies with urinary tract abnormalities detected before birth who were born at or referred to a teaching hospital. PATIENTS: One hundred and twenty-five babies born between June 1989 and November 1992. Sixty-nine babies were born at Westmead hospital and 56 were born elsewhere and referred to Westmead Hospital for investigation. RESULTS: The incidence of uropathy detected before birth among babies born at the teaching hospital was 5.1 per 1000 births. In 60% of these babies, significant abnormalities were confirmed after birth (3.1 per 1000 births). We found a significance of 71% and a specificity of 89% for fetal measurements in predicting significant uropathy. Among all 125 babies the most common abnormalities were pelviureteric junction (PUJ) anomalies (34%), minimal hydronephrosis (26%), ureteric reflux (18%) and multicystic kidney (7%). Pyeloplasty has been performed in 23 (46%) of the 52 kidneys with PUJ anomalies. Renal parenchymal abnormality was detected in four of 22 kidneys with ureteric reflux (18%). Of these four, all were exposed to Grade IV or V ureteric reflux but none had been infected. CONCLUSIONS: Antenatal ultrasound is a sensitive, though nonspecific, tool for the non-invasive identification of congenital abnormalities of the urinary tract, which are common and frequently asymptomatic after birth. Although ureteric reflux may not be predicted from renal measurements, the degree of fetal hydronephrosis indicates the likelihood of obstructive abnormality and, thus, the extent of postnatal investigation required.

Female↗
PubMed1994

A medium term follow-up study of patients with hypertrophic pyloric stenosis.

A structured questionnaire was sent to the parents of 120 children from a cohort 192, who had undergone a pyloromyotomy for pyloric stenosis at Westmead Hospital during the years 1984-91. Information was gained from 85 children in 82 families regarding gastrointestinal complaints and family history of pyloric stenosis. There were few gastrointestinal problems, no reports of recurrent abdominal pain, but two reports of clinically significant vomiting (2.3%) and one of infantile colic. Of the 85 individuals studied, 21 (24.7%) had a positive family history of pyloric stenosis, a higher frequency than previously reported.

Child↗
PubMed1993

A gene for Hirschsprung disease (megacolon) in the pericentromeric region of human chromosome 10.

Hirschsprung disease (HSCR) is characterized by a congenital absence of enteric ganglia along a variable length of the intestine. Although long considered to be a multifactorial disease, we have identified linkage in a subset of five HSCR families to the pericentromeric region of chromosome 10, thereby providing monogenic inheritance in some families. A maximum two-point lod score of 3.37 (theta = 0.045) was observed between HSCR and D10S176, under an incompletely penetrant dominant model. Multipoint, affecteds-only and non-parametric analyses supported this finding and localize this gene to a region of approximately 7 centiMorgans, in close proximity to the locus for multiple endocrine neoplasia type 2 (MEN2). The co-occurrence of these two entities in some families might be attributable to shared pathogenetic origins.

Alleles↗