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Biomedical subjects

K McHugh

Publications and source records attributed to K McHugh.

At least 19 recordsLinked to original sources
PubMed1995

Interleukin-4 induces expression of the integrin alpha v beta 3 via transactivation of the beta 3 gene.

Osteoclastic bone resorption is dependent upon cell-matrix recognition. This process is mediated by the integrin alpha v beta 3 whose expression is enhanced, in avian osteoclast precursors, by bone-seeking steroids. The purpose of this study was to determine if bone-modulating cytokines impact on alpha v beta 3 expression by mouse marrow macrophages (BMMs), known to differentiate into osteoclasts. Of the cytokines tested. Interleukin-4 (IL-4) is most effective in increasing beta 3 mRNA levels by a mechanism involving transactivation of the beta 3 gene. Moreover, IL-4 augmented beta 3 mRNA is mirrored by plasma membrane appearance of alpha v beta 3. As IL-4 induces beta 3 and not alpha v mRNA, the beta 3 chain appears to regulate surface expression of the heterodimer. The functional significance of IL-4-induced alpha v beta 3 is underscored by the fact that, while attachment to fibronectin is unaltered, treatment of BMMs with the cytokine enhances alpha v beta 3-mediated binding to vitronectin 5-fold. Expression of this heterodimer by BMMs driven along a non-osteoclastic lineage suggests alpha v beta 3 may play a role in the inflammatory response of macrophages.

Animals↗
PubMed1995

Experimental colitis alters myenteric nerve function at inflamed and noninflamed sites in the rat.

BACKGROUND & AIMS: Studies in inflammatory bowel disease have shown extensive structural abnormalities in the enteric nervous system of inflamed and noninflamed gut; however, functional correlates are lacking. The aim of this study was to determine the effect of colitis on myenteric nerve function at inflamed and noninflamed sites in rat intestine. METHODS: Tritiated noradrenaline release was measured from longitudinal muscle myenteric plexus preparations from the distal and transverse colon and terminal ileum of rats with colitis induced by trinitrobenzene sulfonic acid or Trichinella spiralis larvae. RESULTS: As characterized by myeloperoxidase activity and histology, both models induced inflammation restricted to the distal colon. In distal colon in trinitrobenzene sulfonic acid colitis, KCl- or electrical field stimulation-evoked 3H release was suppressed by 56% and 60%, respectively; in T. spiralis-infected rats, the KCl-evoked release was suppressed by 58%. 3H release was also suppressed by similar magnitudes in noninflamed transverse colon and terminal ileum of each model. CONCLUSIONS: Experimental distal colitis alters myenteric nerve function in inflamed distal colon and noninflamed gut regions. These changes are independent of the manner in which colitis is induced and provide a basis for the extensive disruption of physiological function observed in inflammatory bowel disease.

Adrenergic Fibers↗
PubMed1995

The post-angiocardiography urogram in children: should it be abandoned?

This study examines the value of the urogram radiograph taken after angiocardiography, in children with suspected congenital heart disease, to screen for co-existent urinary tract abnormalities. A retrospective audit of post-angiocardiography urograms over a three year period 1990 to 1993 is presented. 184 urograms obtained in 166 children were reviewed (86 males; mean age 18.1 months). Twenty-five urograms (13.6%) were obtained in cases where the urinary tract had previously been investigated. These urograms contributed no additional information. Image quality was suboptimal in 62 examinations (33.7%), due to gas, faeces or poor opacification, and two lesions were undetected on suboptimal radiographs. Urinary tract abnormalities were detected in 17 patients (10.2%). These lesions were also detectable at sonography. We suggest that routine post-angiocardiography urograms can be abandoned in favour of sonographic screening of the urinary tract in children with congenital heart disease.

Adolescent↗
PubMed1994

A comparison of cognitive and behavioral inductions of negative mood.

Sixty undergraduate subjects were exposed to one of three depressive mood inductions: cognitive, behavioral, or control. Subjects in the cognitive induction group read negative self-statements consistent with Beck's (1974) cognitive theory of depression. Subjects in the behavioral induction group were exposed to insoluble discrimination problems consistent with Lewinsohn's (1974) behavioral theory that lack of reinforcement produces depression. The control group read a neutral passage. Following the mood induction, subjects rated their current moods using the Multiple Affect Adjective Checklist (MAACL; Zuckerman & Lubin, 1965). The cognitive and behavioral inductions produced significantly higher MAACL total and subscale scores than did the control condition; however, the cognitive and behavioral inductions did not differ from one another. Because the cognitive and behavioral mood inductions appear equally powerful, they may be used by researchers who are attempting to identify variables that are related to subjects' differing responses to behavioral and cognitive influences on depression.

Cognition↗
PubMed1994

Specific learning disability in children with neurofibromatosis type 1: significance of MRI abnormalities.

To determine whether previously reported areas of increased T2 signal intensity on MRI examination in children with neurofibromatosis type 1 (NF 1) are associated with deficits in development and learning common in this population, we evaluated 51 children with NF 1 (aged 8 to 16 years). Forty children completed the full assessment protocol (MRI, medical, psychometric, speech therapy, and occupational therapy assessments). The mean Full Scale IQ scores for the entire study population showed a left shift compared with the normal population, and the distribution of IQ scores was bimodal, suggesting that there are two populations of patients with NF 1--those with and those without a variable degree of cognitive impairment. There was no association between lower IQ scores and any clinical variable. Areas of increased T2 signal intensity unidentified bright objects (UBO+) were present in 62.5% of the study population, and their presence was not related to clinical severity, sex, age, socioeconomic status, macrocephaly, or family history of NF 1. However, compared with children without areas of increased T2 signal intensity (UBO-), the UBO+ group had significantly lower mean values for IQ and language scores and significantly impaired visuomotor integration and coordination. Children with areas of increased T2 signal intensity were at a much higher risk for impaired academic achievement. Children without increased T2 signal on MRI (UBO-) did not significantly differ from the general population in any measure of ability or performance. Areas of increased T2 signal on MRI represent dysplastic glial proliferation and aberrant myelination in the developing brain and are associated with deficits in higher cognitive function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Characterization of suppression of food intake following acute colon inflammation in the rat.

Experimental colitis was induced in rats by intrarectal infusion of trinitrobenzenesulfonic acid and ethanol. Colitis was accompanied by a large suppression of food intake of 3 days duration. The reduction of food intake was effected through a reduction of meal size, with no change in meal frequency. Those same rats demonstrating approximately 70%-80% suppression of daily food intake showed no reduction of sham feeding. These data indicate that malaise alone is inadequate to explain the suppression of food intake associated with acute colitis. Rather, the data suggest that the suppression of eating results from an exaggerated postprandial satiety signal elaborated during the period of acute inflammation, an interpretation consistent with the demonstration of a slowed rate of gastric emptying in association with the colitis.

Analysis of Variance↗
PubMed1992

Infantile hepatic hemangioendotheliomas: significance of portal venous and systemic collateral arterial supply.

This report describes four infants with hepatic hemangioendotheliomas and cardiac failure who had extensive portal venous and systemic collateral arterial supply complicating hepatic arterial embolization. One patient with diffuse hepatic hemangioendothelioma and extensive portal vein supply but minimal systemic collateral arteries showed no improvement after technically successful hepatic artery embolization and died with disseminated intravascular coagulation and sepsis. A second infant with extensive portal vein and collateral supply died without undergoing embolization. Two patients had portal vein-hepatic vein fistulas as well as an extensive systemic arterial supply. Both infants tolerated staged hepatic and collateral artery embolization, although one patient died of congestive heart failure, probably related to pulmonary hemangiomas. The authors conclude that angiographic study of the potential collateral vessels and portal venous circulation should be performed before embolization. Patients with shunting from the portal vein to the hepatic vein and minimal systemic arterial collateral circulation should not undergo hepatic artery embolization.

Angiography↗
PubMed1992

Sonography in thyroid carcinoma in children.

This paper reviews the clinical, sonographic and pathological findings of 20 children with thyroid carcinoma in an attempt to determine the value and limitations of sonography in thyroid neoplasms in this age group. Although sonography is an excellent technique for the evaluation of thyroid disorders and masses, certain limitations must be kept in mind. Microscopic foci of tumour might be missed and sonography cannot predictably differentiate benign from malignant disease. Previous radiation exposure should increase the level of suspicion for malignancy.

Adenocarcinoma↗
PubMed1991

Multiple gastrointestinal atresias: sonography of associated biliary abnormalities.

The pre-operative finding of biliary ductal dilatation in the setting of multiple gastrointestinal atresias has not been previously reported. This paper illustrates the sonographic findings in two neonates with multiple gastrointestinal atresias from the prepyloric region to the rectum. Biliary ductal dilatation was seen in both patients and highly echogenic, mobile intraluminal bowel debris secondary to calcified meconium was evident in one. Post-operative biliary gas was demonstrated on sonography in one case.

Bile Duct Diseases↗
PubMed1991

Wegener's granulomatosis in childhood.

The authors reviewed the medical histories and radiological examinations of five pediatric patients with a histologic diagnosis of Wegener's granulomatosis (WG) seen over a six year period in whom a total of 22 thoracic CT scans were performed. Involvement of both the upper and lower respiratory tracts was seen in all patients at presentation. One patient had subglottic stenosis necessitating tracheotomy. Pulmonary hemorrhage occurred in three patients at initial diagnosis. Classic cavitary lung nodules were seen in two patients--one at initial presentation, the other at relapse. The plain radiographic lower respiratory tract manifestations of pediatric WG were protean both at initial presentation and during follow up. Similarly, disease expression was highly variable on thoracic CT examinations but, overall, multifocal parenchymal infiltrates with or without small peripheral nodules were the commonest thoracic CT manifestations. As a consequence of cytotoxic and corticosteroid therapy the long-term prognosis of WG has improved considerably in recent years. Knowledge of the varied patterns of the primary disease and potential for iatrogenic complications are necessary for successful radiologic assessment of pediatric patients with WG.

Adolescent↗
PubMed1991

Splenic necrosis in Wegener's granulomatosis.

The CT appearance of asymptomatic splenic necrosis in a 11-year-old girl with Wegener's granulomatosis is presented. Sonography showed splenic inhomogeneity with patency of the splenic artery and vein. Follow-up CT showed lobulation and shrinkage of the spleen with return to a normal attenuation.

Adolescent↗
PubMed1991

Delayed presentation of traumatic diaphragmatic hernia.

Nine cases of delayed presentation of diaphragmatic hernia secondary to blunt trauma are presented. The delay in presentation varied from one to 16 years from the time of the original injury. The chest radiography was abnormal in all cases. In some, herniation could be reasonably inferred but in others there were only non-specific signs. Once the diagnosis of delayed presentation of traumatic diaphragmatic hernia is suspected, we have found barium studies to be the most useful confirmatory investigations.

Adult↗
PubMed1991

Simple renal cysts in children: diagnosis and follow-up with US.

To assess the sonographic frequency of simple renal cysts in children, the authors retrospectively reviewed the results of abdominal sonographic studies of 16,102 children performed over a 5-year period between January 1, 1985, and December 31, 1989. Patients with abnormal renal function, dysplastic kidneys, or a family history of polycystic kidney disease were excluded from the study. The authors' review of the sonograms revealed 37 simple cysts in 35 patients (0.22%); the cysts were evenly distributed by age and sex and measured from 0.3 to 7.0 cm in maximum diameter. Sixteen cysts (43%) were in the upper pole of the right kidney. Follow-up sonographic studies of 23 cysts in 22 patients for up to 5 years showed no change in size in 17 cysts (74%). The largest cyst was drained percutaneously; all other cysts were managed conservatively. No patient showed deterioration of renal function. Therefore, the authors concluded that in a pediatric patient demonstrating normal renal function, no further intervention is necessary when a simple renal cyst is identified at sonography.

Adolescent↗