Gastrointestinal manifestations in pediatric AIDS

Current debate over the influence of phonological awareness on early reading development is polarised around small-unit (phoneme) processing and large-unit (onset-rime) processing. These opposing theories were contrasted by assessing the impact of pre-school phonological skills on reading amongst children experiencing their first year of formal instruction by a mixed method. Those beginning readers who could decode nonwords were found to have accomplished this by employing their letter-sound knowledge rather than by making analogies based on familiar rime units. Children displayed this pattern of performance regardless of their pre-school rhyming skills. Further investigations revealed that explicit awareness of onset and rime units was poor, even amongst children whose implicit rhyming skills were excellent. This evidence, together with the children's knowledge of orthographic units, was consistent with the view that letter-sound correspondences rather than onset or rime units formed the basis of their first attempts to utilise phonology in reading. The findings are discussed with reference to instructional influences on early reading and phonological awareness.     

Vascular manifestations in systemic sclerosis (scleroderma)

Progressive systemic sclerosis (PSS), a disease still of unknown origin, is a generalized autoimmune disorder characterized by immunological abnormalities, microvascular dysfunction, and tissue fibrosis. The mechanism leading to selective microvascular injury in PSS is not completely known, however it is now clear that neuropeptides, vascular endothelium, and disturbances in the regulation of fibroblast function are the three major contributors to the increased fibrosis of skin and internal organs. Thus, endothelial cell and fibroblast dysfunction may be linked through the paracrine activity of soluble endothelial cell products: the cytokine cascade (IL-1, TGF-beta-1, PDGF, TNF, etc.). In systemic sclerosis, the exaggerated generalized vasospastic tendency is clinically represented by Raynaud's phenomenon as shown by an early digital arterial closure after cold stimulation, and by an inadequate vasodilatory response to heat. In this review we summarize recently established data that center around the role of adhesion molecules, immune reactions, and aberrant fibroblast biology and metabolism in effecting vascular and connective tissue alterations in this disease. Only a better knowledge of the pathophysiological process involved in scleroderma might lead to the development of new therapeutic approaches.     

Gastrointestinal manifestations of cystic fibrosis: radiologic-pathologic correlation

Cystic fibrosis (CF), the most common lethal autosomal recessive disease in white populations, is characterized by dysfunctional chloride ion transport across epithelial surfaces. Although recurrent pulmonary infections and pulmonary insufficiency are the principal causes of morbidity and death, gastrointestinal symptoms commonly precede the pulmonary findings and may suggest the diagnosis in infants and young children. The protean gastrointestinal manifestations of CF result primarily from abnormally viscous luminal secretions within hollow viscera and the ducts of solid organs. Bowel obstruction may be present at birth due to meconium ileus or meconium plug syndrome. Complications of meconium ileus include volvulus, small bowel atresia, perforation, and meconium peritonitis with abdominal calcifications. Older children with CF may present with bowel obstruction due to distal intestinal obstruction syndrome or colonic stricture, and tenacious intestinal residue may serve as a lead point for intussusception or cause recurrent rectal prolapse. Radiologic studies often demonstrate thickened intestinal mucosal folds in older children and uncommonly show colonic pneumatosis, peptic esophageal stricture due to gastroesophageal reflux, and duodenal ulcer. Appendicitis due to inspissated secretions is uncommon. Obstruction of ducts and ductules produces exocrine pancreatic insufficiency, pancreatitis, cholestasis, cholelithiasis, and cirrhosis with portal hypertension. On imaging studies, the pancreas is commonly small and largely replaced by fat, sometimes displays calcifications, and is rarely replaced by macrocysts. Radiologic features of hepatobiliary disease include an enlarged radiolucent liver from steatosis, gallstones, a shrunken nodular liver, splenomegaly, and portosystemic collateral vessels. With the improved survival of CF patients, an increased risk for developing gastrointestinal carcinomas has been established, many occurring as early as the 3rd decade.     

Gastrointestinal manifestations of vascular anomalies in childhood: varied etiologies require multiple therapeutic modalities

BACKGROUND/PURPOSE: Vascular anomalies, including hemangiomas and vascular malformations afford complex diagnostic and therapeutic challenges when gastrointestinal (GI) manifestations are present. METHODS: Twenty-one patients evaluated or treated in our Vascular Anomalies Program from 1993 through 1997 were reviewed retrospectively with regard to presentation, treatment modalities, and outcome. RESULTS: Four patients had hemangiomas, and 17 had various vascular malformations. GI symptoms began in infancy or early childhood in all patients. Manifestations included GI bleeding (n = 15), obstruction (n = 2), diarrhea (n = 2), ascites (n = 2), pain (n = 1), emesis (n = 1), ileo-ileal intussusception (n = 1), protein-losing enteropathy (n = 1), and hypersplenism (n = 1). Four patients had proven portal hypertension. Fourteen had associated musculoskeletal or cutaneous lesions. Congestive heart failure, partial anomalous pulmonary venous return, pulmonary edema, and pleural or pericardial effusion occurred in one patient each. Bleeding was the most common symptom of both hemangiomas and malformations. Of four patients with hemangiomas, three were treated with corticosteroids or interferon. Endoscopic banding and embolization of an associated arterioportal hepatic shunt were each used in one patient. One patient died. The malformations were treated with resection (n = 8), endoscopic banding or sclerosis (n = 7), percutaneous or intraoperative sclerosis (n = 5), embolization or device interruption (n = 3), and portosystemic shunt (n = 2). GI symptoms were ameliorated in 12 patients with malformation, improved in two, unchanged in two, and one died after prolonged palliation. CONCLUSIONS: Vascular anomalies with gastrointestinal manifestations are heterogeneous in their presentation and type. Although bleeding is the most common symptom of both hemangiomas and vascular malformations, treatment differs. Pharmacological angiogenesis inhibition is the mainstay of hemangioma therapy. Resection, endoscopic or radiologic vascular obliteration, and portal decompression are important in treating vascular malformations. An individualized and interdisciplinary approach is often required to successfully diagnose and treat these complex lesions.     

Manifestations of scleroderma pulmonary disease

Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.     

A case of bleomycin-induced scleroderma

The association of exposure to bleomycin with the development of scleroderma-like cutaneous abnormalities has been reported. We experienced a case of scleroderma involving the hands, feet, and forearms after bleomycin chemotherapy. The present report supports the possible causal relation of bleomycin with scleroderma. Regarding the widespread use of bleomycin, this complication is thought to be under appreciated.     

Peripheral neuropathy in scleroderma

The diagnostic relevance of recording motor evoked potentials (MEPs) after electrical stimulation of the cervical region, as compared with conventional needle electromyography (EMG), was evaluated in 26 patients with brachial plexus (BP) damage of different aetiology, severity and topography. MEP abnormalities (absence or latency increase) were observed in at least one muscle of all the patients, with a global incidence of 61.5% of the muscles examined. Neurogenic EMG signs were present in all but one patient with an incidence of 62.2% of the muscles examined. Combining the two methods, the global incidence of abnormalities rose to 69.9%. MEP abnormalities were consistent with the clinical topography and severity of BP lesions and were fairly parallel with EMG findings. Recording MEPs after percutaneous electrical stimulation of the cervical region may be regarded as a rapid, non-invasive method for quantitative electrophysiological assessment of BP damage.     

Thymoma in a case of scleroderma

A case of scleroderma with manifestations in the oesophagus and both lungs and a concomitant thymic lympho-epithelioma is presented. This case represents a further documentation of the well-established association between thymoma and collagen disorders.     

An immunogenetic study of familial scleroderma

OBJECTIVE: To study the role of the HLA system in the genetic susceptibility to familial systemic sclerosis (SSc). METHODS: HLA class I antigens were determined by classic serological methods and HLA-DRB, -DQA and -DQB genes were analysed by genetic typing in 36 individuals belonging to two families with several individuals affected by SSc. RESULTS: The results did not show any association of the inheritance to SSc with any particular HLA allele in these families but revealed a striking frequency of ANA autoantibodies in healthy spouses of the members of these families. CONCLUSION: The otherwise infrequent familial incidence of SSc does not appear to be primarily linked to the HLA system in this study but it is suggested that other unknown exogenous environmental factors could be implicated in the development of the disease in families.     

Control of fibrosis in systemic scleroderma

Scleroderma is characterized by an excessive deposition of collagen in all involved organs. This is due to an overproduction of extracellular matrix (ECM) molecules following induction of gene expression, whereas there is no evidence that the composition of the connective tissue matrix is altered. Several in vivo studies and in vitro experiments suggest that a close interaction between inflammatory cells and fibroblasts is required for the initial activation of fibroblasts. TGF-beta presumably plays an important role, but other cytokines, e.g., PDGF or FGF, may also be involved. Many of the ECM molecules have been shown to interact closely with fibroblasts and provide signals that regulate fibroblast metabolism. The cellular response towards those signals is a further aspect of fibrosis that has attracted attention during recent years. The altered expression of receptor proteins on the cell surface of scleroderma fibroblasts for example might explain in part the lack of down-regulation of collagen synthesis in late phases of the disease. This review summarizes the alterations of connective tissue in scleroderma, and discusses the role of cytokines as well as the ECM for the regulation of fibroblast function and their implication for the development of fibrosis.     

Drug-induced scleroderma and sclerodermiform conditions

In Tamhane, Hochberg, and Dunnett (1) we focused primarily on step-down test procedures based on contrasts among the sample means to find the minimum effective dose in a dose-response study. In the present article we use the global tests of Bartholomew (2,3) and Hayter (4) in these step-down procedures. We also propose a new step-down procedure that permits tests based on a class of contrasts [step and basin contrasts of Ruberg (5) are examples of such contrasts] that could not be used with the step-down procedures studied in our previous paper because of lack of control of the familywise error rate. A simulation study to compare the four procedures proposed in the present paper with the top four procedures from the previous article is carried out. It is found that the step-down procedure based on Bartholomew's test and the new step-down procedure based on step and modified basin contrasts generally perform better than the other procedures for a wide range of dose-response profiles.     

Coagulation factor XIII in scleroderma

BACKGROUND: In contrast to most major salivary gland malignancies, mucoepidermoid carcinoma has been rarely documented and tentatively accepted as carcinoma ex pleomorphic adenoma. The authors present the cytologic and clinical findings for six examples of these rare tumors. METHODS: The six examples were identified during an extensive review of the authors' salivary gland files, and all were high grade mucoepidermoid carcinomas on histologic evaluation. RESULTS: Overall, mucoepidermoid carcinomas cytologically presented as non-specific high grade malignancies and consisted of highly malignant cells, in clusters or isolated, that were rarely associated with intracellular and extracellular mucin. In only two cases, a background of cellular and stromal elements consistent with pleomorphic adenoma was identified. CONCLUSIONS: Although it is nearly impossible cytologically to distinguish these lesions from other high grade primary or metastatic carcinomas (such as poorly differentiated squamous cell carcinomas, adenosquamous carcinomas, and salivary duct carcinomas), this limitation is not dramatic, as a cytologic diagnosis of high grade malignancy per se allows for proper preoperative patient management.