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Biomedical subjects

C L Trevenen

Publications and source records attributed to C L Trevenen.

At least 19 recordsLinked to original sources
PubMed2001

Age-dependent changes in the regulation of cyclooxygenases in the gastrointestinal tract after gram-negative endotoxemia.

BACKGROUND: Cyclooxygenases (COXs) modulate prostaglandin synthesis in the gastrointestinal tract. Prostaglandins have been shown to have a cytoprotective effect on bowel mucosa in adults, but no similar data are available in neonates. Thus, the purpose of the current study was to evaluate age-dependent changes in gastrointestinal tract COX regulation after Escherichia coli lipopolysaccharide exposure in rats. METHODS: Stomach, small bowel, and large bowel COX-1 and COX-2 mRNA levels (reverse transcription polymerase chain reaction technique) and protein content (Western blot) were obtained from neonates (younger than 3 days old) and adult rats 18 hours after exposure to E. coli O111:B4 lipopolysaccharide toxin. Untreated animals served as controls. RESULTS: Stomach, small bowel, and large bowel tissue COX-1 mRNA levels in the newborn were significantly lower (P < 0.01) than in the adult. No age-dependent differences were found for COX-2 mRNA levels. After lipopolysaccharide exposure, no significant changes in COX-1 levels were seen at either age, whereas COX-2 mRNA levels were increased only in the stomach for both ages. Western blot analysis of small bowel tissue for COX-1 and COX-2 showed no lipopolysaccharide-induced changes in protein content, but the COX-1 content was significantly lower in the newborn (P < 0.01). CONCLUSIONS: In the rat, COX expression in the gastrointestinal tract is regulated in an age-dependent fashion. Lower COX-1 expression and a lack of observable increase in COX-2 mRNA levels in the newborn small bowel after endotoxemia may render the bowel more susceptible to bowel injury early in life.

Age Factors↗
PubMed2000

Disseminated bacille Calmette-Guérin infection in an infant with a novel deletion in the interferon-gamma receptor gene.

Six weeks after receiving BCG vaccination, a Canadian aboriginal infant presented with suspected sepsis, lymphadenopathy and hepatosplenomegaly. Lymph node biopsy revealed macrophages filled with acid-fast bacilli. Mycobacterium bovis was cultured from tissue specimens and there was evidence of concomitant cytomegalovirus disease. The infant died of disseminated BCG infection. A novel deletion at nucleotide 165 in the interferon-gamma receptor (IFN-gammaR1) was identified. The incidence of this mutation in the aboriginal population and the impact on the heterozygous state are unknown.

BCG Vaccine↗
PubMed1995

Hyperglycemia in diarrhea-associated hemolytic-uremic syndrome.

Hyperglycemia is a recognized complication of diarrhea-associated hemolytic-uremic syndrome (D + HUS). Hyperglycemia developed in 8 (6.6%) of 121 patients with D + HUS. A literature review revealed a further 11 patients with D + HUS who developed hyperglycemia. The mortality rate in this group of patients is high. Hyperglycemia is more common in patients with D + HUS uremic syndrome who are female, who have an elevated white blood cell count on admission, and who develop anuria or a central nervous system complication.

Amylases↗
PubMed1993

Xanthine calculi presenting at 1 month of age.

Xanthinuria is a rare cause of nephrolithiasis and is usually due to an inherited abnormality in purine metabolism. A 5-year 6-month-old boy was assessed for a history of recurrent episodes of renal colic. The child first presented with symptoms due to xanthine calculi at 1 month of age, the youngest presentation we were able to identify. Xanthine calculi, although rare, should be considered in the differential diagnosis of nephrolithiasis and ureterovesical junction obstruction in children. Xanthine calculi should also be considered when symptoms suggestive of urinary tract infection are present but the urine culture is negative, and when an orange-brown sediment is noted in the urine or similar coloured stains are found in the nappy.

Humans↗
PubMed1993

Myopathy of the Proteus syndrome: hypothesis of muscular dysgenesis.

The Proteus syndrome is a congenital disorder of growth regulation affecting tissues of mesodermal and ectodermal origin. It is expressed as hemihypertrophy, hemimegalencephaly, muscular overgrowth, verrucous epidermal nevi, haemangiomas and bony dysplasias. Muscle biopsies were examined at 7 and 10 yr of age from a girl with this disease. Several cytoarchitectural alterations of myofibres, proliferation of sarcolemmal nuclei, and other myopathic changes were demonstrated in regions adjacent to other with normal myofibres; the boundaries did not correspond to fascicular margins. A perinuclear and subsarcolemmal distribution of excessive desmin was also found. It is suggested that this myopathy represents a new category of neuromuscular disease, "muscular dysgenesis", due to faulty paracrine growth factors.

Biopsy↗
PubMed1993

Ependymal abnormalities in lissencephaly/pachygyria.

The ependyma was examined in eight children with neuroblast migratory disorders of diverse origin: three cases of lissencephaly type 1 with severe to mild degrees of agyria/pachygyria, four cases of lissencephaly type 2 in Fukuyama muscular dystrophy and the Walker-Warburg syndrome, and one case of hemimegalencephalic pachygyria. Morphological and immunohistochemical abnormalities of the ependyma were strikingly similar in all. Discontinuities were disproportionate to the degree of ventriculomegaly. In some regions, the ependyma remained a pseudostratified columnar epithelium, though basal processes were absent. The poles of the horns of the lateral ventricles were replaced by extensive heterotopic ependymal rosettes. Rosettes and rows of ependyma also were in other subventricular sites. Subependymal nodules of large astrocytes and their processes bulged into the ventricular lumen after infancy. Ependymal cells did not express glial fibrillary acidic protein, but showed persistent expression of S-100 protein, cytokeratin CK-904 and sometimes vimentin long after these proteins normally disappear. An abnormal ependyma in lissencephaly/pachygyria may contribute to disturbances in neuronogenesis, guidance of axonal projections and neuroblast migrations; it may be a primary factor in pathogenesis.

Brain↗
PubMed1993

Diarrhea-associated hemolytic uremic syndrome.

Diarrhea-associated hemolytic uremic syndrome (D+ HUS) is the most common cause of acute renal failure in children. The authors report their experience with D+ HUS with 114 patients assessed in Calgary from 1980 to 1992. Epidemiologic, clinical, and pathologic aspects are discussed.

Adolescent↗
PubMed1991

The human tail and spinal dysraphism.

Recent publications have endeavoured to differentiate between the true, or vestigial tail, and the pseudotail by clinical and pathological examination, and have indicated the benign nature of the true tail. The true tail arises from the most distal remnant of the embryonic tail, contains adipose, connective, muscle, and nerve tissue, and is covered by skin. Pseudotails represent a variety of lesions having in common a lumbosacral protrusion and a superficial resemblance to vestigial tails. A review of the case reports indicates spina bifida to be the most frequent coexisting anomaly with both. A review of occult spinal dysraphism shows it to be associated with cutaneous signs in more than 50% of instances. Three cases of spinal dysraphism with tail-like cutaneous structures are described and their radiological, operative, and pathological findings presented. The classification of each of the appendages into true tail or pseudotail remains obscure. Although the finding of these three tails was the subject of much curiosity, surgical treatment was clearly designed to adequately deal with the associated dysraphic state. The presence of a tail-like appendage in the lumbosacral region should alert the clinician to the possibility of underlying spinal dysraphism. Preoperative assessment must include a complete neurological history and examination as well as computed tomographic or magnetic resonance imaging.

Bone Neoplasms↗
PubMed1990

Thymic-renal-anal-lung dysplasia in sibs: a new autosomal recessive error of early morphogenesis.

We report on 3 sisters with a syndrome of unilobed or absent thymus, renal and ureter agenesis/dysgenesis, and intrauterine growth retardation (IUGR). Two of the 3 infants had a unilobed lung and imperforate anus. Recurrence was detected prenatally by the presence of progressive oligohydramnios and IUGR, a unilateral echogenic cystic mass in the renal fossa, and low amniotic fluid disaccharidases in association with an imperforate anus. Several genetic mechanisms can be invoked to explain this occurrence including autosomal recessive inheritance and an unrecognized chromosome imbalance.

Abnormalities, Multiple↗
PubMed1990

Congenital tracheal stenosis in Pfeiffer syndrome.

We report an infant with Pfeiffer syndrome (acrocephalosyndactyly type V) and a solid cartilaginous trachea lacking rings. This airway abnormality has been reported in a child with Crouzon syndrome but has not been described in Pfeiffer syndrome.

Acrocephalosyndactylia↗
PubMed1990

Acridine orange--RNA histofluorescence of sarcomas and small round cell tumors of childhood.

Forty-nine pediatric malignant neoplasms were stained with acridine orange (AO) fluorochrome to qualitatively evaluate cytoplasmic RNA content. The application of AO as a supplementary stain in surgical pathologic diagnosis is based on the premise that specific neoplastic cell types characteristically and consistently contain few or many cytoplasmic ribosomes. Primitive tumors such as Ewing's sarcoma and primitive neuroectodermal tumors showed negative or low-intensity AO-RNA cytoplasmic staining. Differentiated sarcomas such as rhabdomyosarcomas and lymphomas exhibited moderate to strong AO-RNA cytoplasmic fluorescence. Acridine orange--RNA staining provides an easy, convenient, and inexpensive adjunct in the histopathologic differential diagnosis of sarcomas. It is particularly useful for distinguishing Ewing's sarcomas from other small round cell sarcomas of childhood.

Acridine Orange↗
PubMed1990

Follicular lymphomas in pediatric patients.

The clinicopathologic features of twenty cases of follicular lymphoma (FL) in pediatric patients are described. Fifteen boys and five girls were 2 to 20 yr (mean 10 yr) of age at diagnosis. In ten cases (50%) the lymphoma was localized in lymph nodes and in ten cases (50%) in extranodal sites. Fifteen patients had stage I, two stage II and three stage III disease at the time of presentation. The faucial tonsils were the primary site in seven cases, other head and neck sites in five, inguinal lymph nodes in four and possibly another, and the abdomen in two. Six cases (30%) were classified as follicular small cleaved cell type (FSCC), five (25%) as follicular mixed small cleaved and large cell (FMC), and nine (45%) as follicular large cell (FLC). The architectural pattern was purely follicular (F) in five cases (20%), predominantly follicular (F greater than D) in six (30%), follicular and diffuse (F = D) in six (30%) and predominantly diffuse (F less than D) in three (15%). In one case a progression from F greater than D LC to F less than D LC was documented. All patients attained complete remission (CR). One died of acute lymphoblastic leukemia 7 yr after the original diagnosis of FSCC non-Hodgkin's lymphoma (NHL), but the others are all alive and free of disease with a follow-up ranging from 6 mo to 16 yr (median 4 yr). In three patients therapy was initially deferred with no known adverse influence on outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

The histopathology of the upper airway in the neonate following mechanical ventilation.

Laryngotracheobronchial lesions were carefully documented in 26 neonatal autopsies and were classified into two main types. Type I lesions were focal desquamative or ulcerative, asynchronous, and variable in severity involving areas exposed to contact with endotracheal tube or suction catheter. These lesions are most likely due to trauma of artificial ventilation. Type II lesions were diffuse, necrotizing, more synchronous and uniform in severity involving tissues distal to the endotracheal tube and extending to second or third generation bronchi. The early or mild type II lesions consisted of coagulative necrosis of epithelial cells and mucosal oedema. The late or severe type II lesions showed features similar to those of necrotizing tracheobronchitis described by Metley et al. All the cases with type II lesions had been ventilated with 100 per cent oxygen continuously for at least 3 h during life. The use of pure oxygen may be an important factor leading to necrotizing tracheobronchitis.

Bronchi↗
PubMed1988

The BOR syndrome and renal agenesis--prenatal diagnosis and further clinical delineation.

This is the first report of prenatal diagnosis of a fetus with brachio-oto-renal dysplasia (BOR) syndrome with right-sided renal agenesis and severe left hypoplasia. The father of this fetus had malformed external ears, a left-sided preauricular pit and branchial cyst, and bilateral mild to moderate deafness without a demonstrable renal anomaly. This family highlights the variable expressivity seen in the autosomal dominant BOR syndrome, the importance of genetic counselling for families with BOR syndrome, and the aetiologic heterogeneity of renal agenesis.

Abnormalities, Multiple↗
PubMed1988

Expression of markers shared between human natural killer cells and neuroblastoma lines.

Neuroblastoma is a tumor of neuroectodermal origin arising most commonly from the adrenal medulla. We have examined the ability of several monoclonal antibodies which recognize markers predominantly expressed on human natural killer (NK) cells to react with neuroblastoma cell lines in vivo derived sections of tumor. HNK-1 (Leu 7) is a monoclonal IgM antibody which recognizes a carbohydrate epitope on NK cells and a wide range of tumor cell types. We have shown that HNK-1 recognizes the human neuroblastoma lines SMS-KCNR, SMS-KAN, NMB/N7, and IMR/5. Expression of this antigen on cell lines can be slightly increased by retinoic acid-induced differentiation of the cells. N901 (NKH1), a monoclonal antibody raised against interleukin 2-dependent human NK cell lines also recognizes all human neuroblastoma cell lines examined. This expression is independent of differentiation induction and levels remain unaltered following retinoic acid treatment of the cell lines. Lastly, with monoclonal antibody 49H.8, it has been found that reactivity of the lines is weak until induction of differentiation, after which highly significant increases of reactivity are seen. 49H.8 recognizes several cryptic carbohydrate antigens with varying affinities, shown to identify mouse and rat NK cells. In contrast to other NK markers, human neuroblastoma cell lines did not express significant reactivity with B73.1, Leu 11b, or Leu 18. Immunohistochemical staining of sections of human neuroblastoma tumors correlated with the in vitro findings; however, staining with N901 and 49H.8 was only seen on frozen sections, not paraffin-embedded. The significance of shared NK cell-neuroblastoma/neuron antigens is currently under investigation.

Animals↗