Distinctive activation patterns in constitutively active and gefitinib-sensitive EGFR mutants

Mutations in the kinase domain of epidermal growth factor receptor (EGFR) are associated with clinical responsiveness to gefitinib in patients with non-small-cell lung cancers (NSCLC). Recently, we have identified many novel EGFR mutations in NSCLC tissues. In this study, we found that gefitinib could suppress the tyrosine phosphorylation of most EGFR mutants better than the wild-type receptor. However, gefitinib had quite variable growth-suppressive effects on different EGFR mutant-expressing cells. All tested EGFR mutants have high basal phosphorylation at multiple tyrosine residues. Upon EGF stimulation, the mutated EGFRs did not have apparently stronger phosphorylation at tyrosines 845, 992, 1,068, and 1,173 than the wild-type receptor. However, stronger phosphorylation at tyrosine 1,045 was observed in the S768I, L861Q, E709G, and G719S mutants. The E746-A750 deletion mutant was less responsive to EGF than the wild-type and other mutant receptors. The S768I, L861Q, E709G, and G719S mutants were refractory to EGF-induced ubiquitination and had more sustained tyrosine phosphorylation. E709G and G719S also lacked EGF-induced receptor downregulation. Our results indicate that, in addition to sensitivity to gefitinib, EGFR mutations also caused various changes in EGFR's regulatory mechanisms, which may contribute to the constitutive activation of EGFR mutants and oncogenesis in NSCLC.

Solitary hepatic lymphangioma--a case report

Hepatic lymphangioma is an extremely rare benign neoplasm that is usually associated with lymphangiomas of other viscera. We report a patient with huge, solitary hepatic lymphangioma involving only the liver. The clinical features and computed tomography findings of this case are described.

Bronchoscopic Nd-YAG laser surgery for tracheobronchial mucoepidermoid carcinoma--a report of two cases

Mucoepidermoid carcinoma (MEC) of the tracheobronchial tree represents 0.2% of all lung tumours. It arises from the excretory ducts of the bronchial mucosa and is classified into low- and high-grade tumours using criteria derived from similar tumours of the major salivary glands. Low-grade MEC behaves in a benign fashion with less parenchymal and hilar lymph nodal invasion. The traditional method of treatment is by thoracotomy. The bronchoscopic approach to this lesion using lasers has rarely been reported. This article reports two cases of low-grade tracheobronchial MEC, which were both managed through bronchoscopic neodymium yttrium aluminium garnet (Nd-YAG) laser surgery. The patients were free from disease, 26 and 36 months after surgery. Bronchoscopic laser surgery promises to be an effective alternative treatment modality for tracheobronchial MEC. It is minimally invasive, results in less hospital stay and does not impair pulmonary functions.

Laparoscopic cholecystectomy for gallbladder lymphangiomas

Intraabdominal lymphangiomas are rare benign tumors that can be difficult to diagnose preoperatively. The clinical presentation of these tumors is variable and potentially misleading. Therefore, complex imaging studies are required to evaluate this condition. Ultrasound and CT scan are important to make the correct preoperative diagnosis and also provide important information regarding location, size, and adjacent organ involvement. The treatment of choice is complete excision. This report describes two patients with cystic lymphangiomas originating in the gallbladder. The correct diagnosis was made preoperatively in one patient, and both patients were treated successfully by laparoscopy.

Decrease of deleted in malignant brain tumour-1 (DMBT-1) expression is a crucial late event in intrahepatic cholangiocarcinoma

AIMS

To investigate the participation of DMBT-1, a candidate tumour suppressor gene, in the development of intrahepatic cholangiocarcinoma via intraductal papillary neoplasm of the liver (IPN-L) arising in hepatolithiasis. DMBT-1 plays a role in mucosal immune defence.

METHODS AND RESULTS

The expression of DMBT-1 was examined immunohistochemically in biliary epithelial cells in hepatolithiasis (n = 25), invasive and non-invasive cholangiocarcinoma associated with hepatolithiasis (n = 52), IPN-L with hepatolithiasis (n = 49), cholangiocarcinoma without hepatolithiasis (n = 32), and 10 normal control livers. DMBT-1 was expressed more frequently in the biliary epithelia of hepatolithiasis when compared with normal livers (P < 0.05). DMBT-1 expression was also frequent in IPN-L (57%) and non-invasive cholangiocarcinoma (79%). By contrast, DMBT-1 was decreased in invasive cholangiocarcinoma with and without hepatolithiasis (50% and 30%, respectively) (P < 0.05). The homozygous deletion of the DMBT-1 gene was recognized in four (20%) of 20 cholangiocarcinoma tissues and two (50%) of four cholangiocarcinoma cell lines, corresponding to the reduction of DMBT-1 expression. No deletion was detected in hepatolithiasis tissues.

CONCLUSION

DMBT-1 expression is increased in IPN-L and non-invasive cholangiocarcinoma as well as in biliary epithelia in hepatolithiasis. Decreased expression of DMBT-1 and homozygous deletion of the DMBT-1 gene in invasive cholangiocarcinoma suggest that they occur in the late stage of cholangiocarcinogenesis.

Histopathological and CT features of pulmonary sclerosing haemangiomas

AIM

To demonstrate the computed tomography (CT) features of pulmonary sclerosing haemangiomas.

MATERIALS AND METHODS

Six pathologically proven sclerosing haemangiomas were included in this retrospective review. Patients consisted of five women and one man aged 20-54 years (mean, 34.5 years). Their CT features were recorded according to enhancement patterns and the presence of a tail sign, prominent pulmonary artery sign, air-trapping sign, presence of calcification or cystic spaces, consolidation, and interstitial infiltration. The predominant composition of an individual sclerosing haemangioma was documented by means of microscopy.

RESULTS

Inhomogeneous enhancement was frequently present and depended on the various compositions of the tumours, especially those in sclerotic and predominantly papillary predominant types. The presence of a tail sign, intra-tumoural cystic areas, and a prominent artery sign were the frequent features in our cases.

CONCLUSION

Sclerosing haemangioma should be considered in young or middle-aged female patients whose CT images show them having an inhomogeneous enhancing soft tissue mass with a smooth outline and with above the aforementioned features.

Biliary papillary neoplasm of the liver

Biliary papillary neoplasia of the liver characterized by intraductal papillary growth of neoplastic biliary epithelia with a fine fibrovascular stalk has been sporadically reported, and includes intraductal growing cholangiocarcinoma and biliary papillomatosis. In addition, biliary papillary dysplasia and in situ and microinvasive carcinoma with papillary configuration reported in hepatolithiasis and in other chronic biliary diseases, could be included in this category. Usually, they arise in the intrahepatic large bile ducts, and the neoplastic and non-neoplastic parts of the intrahepatic biliary tree show saccular and segmental dilatation with mucin hypersecretion. This neoplasia frequently shows intraductal spreading and peribiliary glandular involvement. Acute repeated episodes of cholangitis or obstructive jaundice are a frequent clinical manifestation. Gastroenteric metaplasia with aberrant expression of cytokeratin 20, MUC2, MUC5AC, and/or MUC6, is frequent in the neoplastic parts, and biliary epithelial dysplasia with such metaplasia may give rise to in situ and then invasive carcinoma in hepatolithiasis. Interestingly, this type tends to contain foci of mucinous carcinoma elements, and this element may be predominant (mucinous carcinoma). Some may progress to "mucinous biliary cystadenocarcinoma" without ovarian mesenchymal stroma and with intraluminal continuous growth into the neighboring bile duct lumens. Interestingly, the biliary papillary neoplasm resembles histologically, phenotypically and clinically intraductal papillary mucinous neoplasm of the pancreas which is now being established as an infrequent, slow-growing pancreatic neoplasm. Recognition of such biliary papillary neoplasm with respect to the pancreatic equivalent may lead to a better understanding and further studies of the intrahepatic biliary neoplasm.

Decomposition of 2-naphthalenesulfonate in aqueous solution by ozonation with UV radiation

This study investigates the ozonation of 2-naphthalenesulfonate (2-NS) combined with ultraviolet (UV) radiation. Naphthalenesulfonic acids are of importance as dye intermediates for the dye and textile auxiliary industries. Its derivatives, such as 2-NS, have been found in rivers and tannery effluents causing pollution problems. Thus, the 2-NS is of concern for the aquatic pollution control especially in the surface and waste waters. Ozonation combined with UV radiation is employed for the removal of 2-NS in the aqueous solution. Semibatch ozonation experiments were proceeded under different reaction conditions to study the effects of ozone dosage and UV radiation on the oxidation of 2-NS. The concentrations of 2-NS and sulfate are analyzed at specified time intervals to elucidate the decomposition of 2-NS. In addition, values of pH and oxidation reduction potential are continuously measured in the course of experiments. Total organic carbon is chosen as a mineralization index of the ozonation of 2-NS. The mineralization of 2-NS via the ozonation is remarkably enhanced by the UV radiation. These results can provide useful information for the proper removal of 2-NS in the aqueous solution by the ozonation with UV radiation.

Prediction of the outcome of pull-through surgery for Hirschsprung's disease using acetylcholinesterase activity

BACKGROUND AND PURPOSE

Advances in surgical procedures for the treatment of Hirschsprung's disease have afforded the majority of patients a satisfactory outcome after definitive corrective surgery. However, some patients continue to have signs of persistent bowel dysfunction despite adequate resection of the aganglionic bowel segment. The definite etiology of persistent bowel dysfunction in these patients remains controversial.

MATERIALS AND METHODS

The acetylcholinesterase activity in the proximal resection margin of pull-through surgical specimens collected from September 1992 to June 1998 was evaluated and correlated with clinical outcome.

RESULTS

A total of 24 patients were studied, 15 males and 9 females. The follow-up period ranged from 1 year 7 months to 7 years 6 months. The Soave procedure was performed in 17 cases and the Duhamel in 7. Twenty cases had a good or fair clinical outcome and four (16.7%) had a poor outcome. There was no mortality. Among the 20 patients with a good or fair outcome, the acetylcholinesterase activity in the proximal section margins was not increased in 12, mildly increased in seven, and moderately increased in one. The four cases with poor outcome all had moderately increased acetylcholinesterase activity in at least one specimen. The association between moderately increased acetylcholinesterase activity and poor surgical outcome was significant (p = 0.0005). In contrast, there was no association between the surgical method (Soave or Duhamel) used and clinical outcome (p = 0.55).

CONCLUSION

Acetylcholinesterase activity in the proximal resection margins of pull-through surgical specimens is a useful indicator for predicting the postoperative outcome in Hirschsprung's disease.

Varied clinical patterns, physical activities, muscle enzymes, electromyographic and histologic findings in patients with post-polio syndrome in Taiwan

STUDY DESIGN

A study of the clinical features, physical activity, muscle enzyme, electromyography and histopathological alternations of muscles in patients with post-polio syndrome (PPS).

OBJECTIVE

To assess the varied patterns of PPS in Taiwan.

SETTING

Taiwan.

METHODS

Thirty-one patients who fulfill the inclusion criteria of PPS were selected for study. Clinical features, physical activity scale, serum concentrations of creatine kinase, electromyography and histopathological alterations of muscles were assessed and correlated to the causes of PPS patients.

RESULTS

Patients with PPS in Taiwan are relatively young, with a mean age of 39.3 years. Elevated concentration of creatine kinase was found predominantly in male patients with higher physical activities. Electromyographic examinations as well as histological tests of affected muscles revealed prominent evidence of chronic and active denervation with reinnervation in PPS patients.

CONCLUSION

Patients with PPS in Taiwan are young. Thus, PPS should not be attributed to aging. Physical attrition with degradation of nerve terminals is considered the main cause of this disease.

SPONSORSHIP

This study was supported by the National Science Council, Republic of China under grant no. NSC-83-0412-B002-302.

Cytomegalovirus infection and proinflammatory cytokine activation modulate the surface immune determinant expression and immunogenicity of cultured murine extrahepatic bile duct epithelial cells

Murine extrahepatic bile duct epithelial cells (MEBEC) were isolated from extrahepatic bile ducts of BALB/c mice and established in primary culture. The epithelial origin was confirmed by positive cytokeratin 19 staining for these cells and the presence of microvilli and tight junctions under electron microscopy. By immunofluorescent staining with monoclonal antibodies and flow-cytometric analysis, MEBEC in culture constitutively express low levels of intercellular adhesion molecule (ICAM)-1, class I and class II major histocompatibility (MHC) antigens. The expression of ICAM-1 was significantly increased by interferon gamma (INF-gamma) or tumour necrosis factor alpha (TNF-alpha) stimulation. Class I and class II antigen expression were significantly enhanced by INF-gamma and in vitro murine cytomegalovirus (MCMV) infection. MEBEC infected with MCMV revealed a progressive cytopathic effect. MEBEC activated by INF-gamma or infected by MCMV induced a low but significant proliferation of allogeneic T cells and displayed a significant decrease in the absorbance at O.D. 550 nm in a microtitre tetrazolium assay after these treated cells were co-cultured with allogeneic T cells. These results suggest that following the up-regulation of surface MHC antigen and adhesion molecule expression with cytokines or MCMV, the MEBEC can function as antigen-presenting cells and initiate T-cell proliferation, which in turn trigger the recognition of MEBEC by effector T-cell-mediated cytotoxic responses. These findings may be implicated in the pathogenesis of virally induced, immune-mediated extrahepatic bile duct damage disorders.

Maternal question-asking of Japanese children with Down syndrome and with no disability

In an extension of maternal question-asking to Japanese children during free play and at meal time each of 20 mother-child dyads was videotaped at home. The mothers of children with Down syndrome asked more questions during free play at meal time, and for the sum of these two. Also, they produced more requests for information during free play and for combined conditions and fewer clarification requests during free play. The results were compared to those of the previous study of Taiwanese mothers.

Langerhans' cell histiocytosis presenting with a para-aortic lesion and heart failure

Langerhans' cell histiocytosis (LCH) is an uncommon disease with variable manifestations. We report a case of LCH with the unusual initial presentations of chest pain and progressive heart failure in a 5-year-old boy. Chest radiography revealed a wide mediastinum with cardiomegaly. Electrocardiography showed first-degree atrioventricular block and an inverted T wave over V4-V6. Echocardiography, computed tomography, and magnetic resonance imaging of the chest all showed an infiltrating lesion that enveloped the entire heart, great vessels, and coronary arteries. Pathologic examination of the biopsy specimen revealed LCH. Chemotherapy, which included prednisolone, vincristine, methotrexate, and 6-mercaptopurine, had only a minimal effect on the tumor. After the addition of etoposide, the lesion decreased in size, and the symptoms and signs of heart failure and chest pain were ameliorated.

Focal nodular hyperplasia of the liver in a child

We present a case of focal nodular hyperplasia (FNH) of the liver in a 7-year-old girl. The hepatic tumor was found incidentally on physical examination at school. During surgery, a hypervascular mass with a nodular surface was found to be confined to the right lobe of the liver (mainly in segments 5 and 6). The brownish tumor and the gallbladder were completely removed. Pathologic examination revealed a 10 x 9 x 5-cm mass with a central scar and radiating septa, consistent with the diagnosis of FNH. The postoperative course was complicated by subhepatic effusion, which was resolved by percutaneous computed tomography-guided drainage. She remained well 2 years after surgery.

Congenital interstitial cell of cajal hyperplasia with neuronal intestinal dysplasia

Interstitial cells of Cajal (ICCs) are intestinal pacemaker cells that initiate peristalsis in the stomach and intestine, and are considered to be precursors of gastrointestinal stromal tumors (GISTs). We report a 2-year-old girl who suffered from scanty stool passage since birth. On barium enema, the distal colon was rigid with narrow lumen, whereas the proximal colon was dilated and atonic. She received right hemicolectomy and ileostomy. Histopathologically, there was continuous proliferation of spindle cells located between the layers of the muscularis propria throughout the right colon. These spindle cells were positive for c-kit and CD34 but negative for myogenic or neurogenic markers, indicating they are ICCs. No germline or somatic mutation of the juxtamembrane domain of c-kit gene was detected. In addition, the changes of the submucosal plexus fulfilled the histologic criteria of neuronal intestinal dysplasia type B. To our knowledge, this is the first reported case of congenital ICC hyperplasia. Further studies of ICC development may contribute to better understanding of the pathogenesis of this congenital malformation and the tumorigenesis of GIST.

Antenatal diagnosis of congenital hepatoblastoma in utero

A fetus with a huge hepatic tumor was detected by sonography at 36 weeks of gestation. The mass appeared as a single, solid and polylobular tumor located in the right lobe of the liver. Foci of hemorrhage, necrosis and some tiny calcifications were seen. The adjacent right kidney appeared normal but was displaced. The right adrenal gland was not visualized. Three-dimensional power Doppler sonography further depicted the corresponding vascular anatomy of the tumor, including its vascularization pattern and blood supply. The tumor was situated to the right of the umbilical vein and portal sinus, possibly deriving its blood supply from the portal circulation. The fundamental findings suggested the diagnosis of hepatoblastoma by exclusion of other possibilities. The baby was delivered by Cesarean section at 36 weeks' gestation, due to signs of fetal distress. Unfortunately, hypotension, tachycardia, and tachypnea developed shortly after birth. Surgical intervention was performed, but intractable bleeding occurred intra-operatively. The infant died at 6 days of age. Autopsy confirmed the diagnosis of hepatoblastoma. We believe this is the first reported case of the antenatal diagnosis of congenital hepatoblastoma.

[The treatment of severe complications of laparoscopic cholecystectomy]

The treatment of 24 cases of severe complications of laparoscopic cholecystectomy (LC) in 1993-1998 is reported. Among them, 16 cases were from the other hospitals. The patients included 14 cases of bile duct injury, 3 cases of bile leak, 1 case of duodenal injury, 5 cases intraoperative hemorrhages, 1 case mediastinal emphysema. The data showed that bile duct injury was the most severe complication of LC. It is suggested that in order to prevent the complications a training of operators on adaptive exercise and standard intraoperative procedure should be undertaken. The diagnosis and treatment of severe complications are discussed and some useful advice is given in this paper.

Accurate diagnosis of Helicobacter pylori infection by stool antigen test and 6 other currently available tests in children

Invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection. Because H pylori infection is acquired in childhood and adolescence, accurate diagnosis of the infection in the pediatric population is important. We conducted a study to compare invasive tests: culture, biopsy urease test, histology, and polymerase chain reaction on gastric biopsy specimens, with noninvasive tests: serology, (13)C-urea breath test, and a new diagnostic modality, stool antigen test to diagnose H pylori infection. A total of 53 children with symptoms were enrolled in this study, and all had completed the 7 diagnostic tests for H pylori. All the diagnostic tests except serology were excellent methods of diagnosing H pylori infection in children; the diagnostic accuracy was as follows: stool antigen test 96.2%, biopsy urease test 96.2%, histology 98.1%, polymerase chain reaction 94.3%, culture 98.1%, (13)C-urea breath test 100%, and serology 84.9%. The stool antigen test, being highly sensitive and specific, will be potentially very helpful in diagnosing H pylori infection in children.

Spontaneous bowel perforation in infants and young children: a clinicopathologic analysis of pathogenesis

BACKGROUND

In children beyond the neonatal stage, spontaneous bowel perforation with no specific cause is rare. It has attracted little notice and does not fit into any established clinical category. This often results in treatment delays. To determine the underlying pathogenesis, a clinicopathologic analysis of this group of patients was performed.

METHODS

From 1984 through 1997, 15 previously healthy children (10 boys and 5 girls) with bowel perforations were enrolled in this study. Children in whom the specific cause was established were excluded. The ages of the patients ranged from 3 months to 5 years, 5 months (average age: 2 years, 4 months). Data on clinical course, surgical and pathologic findings, and outcomes were analyzed.

RESULTS

All the patients had high fever and acute, watery diarrhea with clinical dehydration. Abdominal distension developed and bowel perforation ensued 5 to 30 days after the onset of diarrhea. In all cases, the perforation consisted of either an isolated patch of bowel (n = 8) or patchy lesions in a segment (n = 7), which was confined to one of the following three anatomic watershed areas: the splenic flexure (n = 7); the lower sigmoid (n = 3); and the ileocecal region (n = 5). One patient died, and three had major sequelae including intra-abdominal abscess, adhesion ileus, and peristomal fistula. Specimens from 13 patients were submitted for histopathologic evaluation. All specimens had acute suppurative inflammation diffusely around the perforation site. Seven had areas of coagulation necrosis of the muscularis propria, especially in the inner circular muscle layer.

CONCLUSION

In acute diarrheal diseases, dehydration may cause bowel ischemia and lead to perforation. Physicians should be alert to the possibility of this abdominal catastrophe when progressive abdominal distension followed by acute diarrheal episodes occurs in children.

Metabolic disorders mimicking Reye's syndrome

BACKGROUND

Several metabolic disorders such as encephalopathy and hepatic dysfunction have been described as Reye's-like syndrome because they present with similar clinical manifestations that mimic Reye's syndrome. We performed a retrospective study to explore the underlying metabolic etiologies of Reye's-like syndrome in patients treated at National Taiwan University Hospital.

METHODS

From January 1991 to June 1998, 19 children with a syndrome fitting the Reye's-like syndrome description were identified for study. Urine organic acid analysis, plasma amino acid analysis, liver pathology, and skin fibroblast enzyme assays were studied during the acute stage of illness.

RESULTS

The etiologies of patients' syndromes included urea cycle disorders (n = 7), glycogen storage disease type Ia (4), primary carnitine deficiency (2), hereditary fructose intolerance (1), methylmalonic acidemia (2), and 3-hydroxy-3-methylglutaric acidemia (1). Fatty acid oxidation defects were suspected in the remaining two cases.

CONCLUSIONS

A significant number of patients who present with Reye's-like syndrome have an underlying inherited metabolic disorder. In patients with Reye's-like syndrome, an accurate diagnosis is essential to ensure normal growth and development and to prevent recurrence of the condition.

Allelic loss at chromosome band 6q14 correlates with favorable prognosis in hepatocellular carcinoma

Cytogenetic and molecular studies have frequently shown chromosome 6q deletions in non-Hodgkin lymphoma and several human cancers. There have been few studies concerning chromosome 6q deletion in hepatocellular carcinoma (HCC), and most of these studies have focused on region 6q26-27. We previously described frequent allelic loss at 6q14 in HCC. As a step toward narrowing the scope of search for tumor suppressor genes, we used a series of yeast artificial chromosome clones that map to the long arm of chromosome 6 (6q14-6q22) by fluorescence in situ hybridization (FISH) to define the minimal common region of allelic loss in 25 cases of HCC. Altogether, 12 tumors had allelic loss on 6q (48%). Eleven of the 12 tumors had polysomy of chromosome 6 with evident intratumor cytogenetic heterogeneity. The minimal common region of allelic loss lies within a 2-cM region at 6q14, flanked by D6S458 (849_d_8) and D6S275 (911_a_3). Clinicopathologic correlation between the 12 patients with allelic loss at 6q and the 13 patients without allelic loss showed no significant differences in any basic characteristics except survival. Patients with allelic loss at 6q had a much longer median survival time than those without allelic loss (50 months vs. 11 months, P = 0.0019). Only 5 of the 25 HCC patients were still alive at the time of this study, and all of them had allelic loss at 6q, which is also statistically significant (P = 0.037, alive vs. dead). The association of allelic loss at 6q with polysomy implies that this may be a progression-associated event in HCC. The correlation of allelic loss at 6q with long survival suggests a complex mechanism of tumorigenesis in HCC and is worthy of further investigation.