A link between c-Myc-mediated transcriptional repression and neoplastic transformation

Recent studies indicate that the transcription factor c-Myc contributes to oncogenesis by altering the expression of genes involved in cell proliferation, but its precise function in neoplasia remains ambiguous. The ability of c-Myc to bind the sequence CAC(G/A)TG and transactivate appears to be linked to its transforming activity; however, c-Myc also represses transcription in vitro through a pyrimidine-rich cis element termed the initiator (Inr). In transfection experiments using the adenoviral major late (adML) promoter, which contains two Myc binding sites and an Inr, we determined that c-Myc represses transcription through the initiator in vivo. This activity requires the dimerization domain and amino acids 106 to 143, which are located within the transactivation domain and are necessary for neoplastic transformation. We studied a lymphoma-derived c-Myc substitution mutation at 115-Phe, which is within the region required for transcriptional suppression, and found the mutant more effective than wild-type c-Myc in transforming rodent fibroblasts and in suppressing the adML promoter. Our studies of both loss-of-function and gain-of-function c-Myc mutations suggest a link between c-Myc-mediated neoplastic transformation and transcriptional repression through the Inr.

Identification of immunodominant, group-specific and subcomplex-specific, continuous epitopes in the core regions of Japanese encephalitis virus using synthetic peptides

Two flaviviruses, Japanese encephalitis (JE) virus and Dengue (DEN) virus which have high pathogenicity for humans, continue to pose a serious public health problem in tropical and subtropical countries of the world. In order to identify the immunodominant B-cell epitopes for diagnostic application, we have prepared a series of 15-mer synthetic peptides from JE virus core protein based on computer analysis. Four linear, immunodominant epitopes corresponding to amino acids 91-105 (P78), 1-15 (P73), 8-22 (P74), and 34-48 (P75) of JE virus core proteins were identified by employing an enzyme-linked immunosorbent assay (ELISA), using high-titered immune sera from JE-vaccinated children. P78 was found to be the most immunodominant. The sero-specificity of these peptides was tested by binding to seroconverted samples from JE and DEN-1 patients. P78 and P74 belonged to group-specific epitopes which reacted with both JE and DEN-1 patient sera. P73 and P75 belonged to subcomplex-specific epitopes which reacted only with JE but not with DEN-1 patient sera. The study suggests that these peptides corresponding to the immunodominant epitopes of JE virus core protein might have the potential to be used as peptide-based diagnostic reagents for the detection and differentiation of JE and DEN antibody responses.

Prognostic value of p53 in muscle-invasive bladder cancer treated with preoperative radiotherapy

OBJECTIVES

The relationship of p53 mutations as analyzed immunohistochemically to radiation response and therapeutic outcome was examined in a cohort of 301 patients with muscle-invasive transitional cell carcinoma of the bladder treated relatively uniformly with preoperative radiotherapy (50 Gy in 25 fractions) 4 to 6 weeks prior to radical cystectomy.

METHODS

Adequate formalin-fixed paraffin-embedded archival tissue for the immunohistochemical staining of p53 using antibody DO1 was obtained in 109 patients. The median follow-up for those living was 91 months.

RESULTS

Overall, p53 staining was positive in 56% of the cases, with 60% positive in Stage T2 (n = 48), 42% in Stage T3a (n = 31), and 63% in Stage T3b (n = 30). Overexpression of p53 did not correlate with actuarial local control, distant metastasis freedom, disease freedom, or overall survival. However, significant associations were seen when these analyses were limited to patients with clinical Stage T3b disease. In this subgroup, the actuarial 5-year rates for patients with p53 positively and negatively stained tumors were 55% and 100%, respectively, for distant metastasis freedom (P = 0.01), 51% and 91% for disease freedom (P = 0.04), and 32% and 91% for overall survival (P = 0.006). Cox proportional hazards models that included p53 staining and other prognostic factors of significance in the univariate analyses revealed p53 to be independently predictive of survival for patients with Stage T3b disease.

CONCLUSIONS

The prognostic value of p53 immunostaining rested with Stage T3b patients. Although no correlations were found with radiation response, p53 positivity in this subgroup was associated with a higher rate of distant metastasis and reduced overall survival. For these patients, p53 negativity would indicate that aggressive local treatment (that is, preoperative radiotherapy and cystectomy) is sufficient, whereas p53 positivity would indicate that multiagent chemotherapy is required because of the increased risk of distant metastasis.

Gastrointestinal bleeding after hepatic transcatheter arterial embolization in patients with hepatocellular carcinoma

BACKGROUND

Transcatheter arterial embolization is a popular palliative treatment for patients with hepatocellular carcinoma, but the incidence of post-treatment gastrointestinal bleeding is not well-defined.

METHODS

We retrospectively analyzed 206 patients with hepatocellular carcinoma who received transcatheter arterial embolization and compared them with 193 patients with hepatocellular carcinoma who underwent angiography along.

RESULTS

Twenty-three episodes (8.5%) of gastrointestinal bleeding occurred within 3 months of hepatic transcatheter arterial embolization following 269 procedures involving 206 patients with hepatocellular carcinoma. Eight episodes (3.0%) of esophageal variceal bleeding and 15 episodes (5.5%) of nonvariceal bleeding were found. The sites of the nonvariceal bleeding episodes were the stomach (n = 7), duodenum (n = 5), and colon (n = 3). When compared with other sources, bleeding from esophageal varices took place earlier, required intensive treatment, and led to a higher mortality. Among another 193 patients with hepatocellular carcinoma who received angiography only, 6 patients developed gastrointestinal bleeding within 3 months (3.1%), and all bled from esophageal varices.

CONCLUSIONS

This study suggests that esophageal variceal bleeding may occur after both angiography and transcatheter arterial embolization. Nonvariceal bleeding episodes, which were usually milder than episodes of variceal bleeding, may be related to the embolization procedure itself.

Clinicopathological study of colorectal mucinous carcinoma in Taiwan: a multivariate analysis

The clinicopathological significance of colorectal mucinous carcinoma is controversial, although some authors feel mucinous carcinoma has a worse prognosis than that of non-mucinous carcinoma. To clarify the significance of this type of carcinoma in Taiwan, a retrospective review of patients with colorectal carcinoma treated at Chang Gung Memorial Hospital between 1984 and 1988 was undertaken. During this period, 53 mucinous carcinomas and 401 non-mucinous carcinomas fulfilling the inclusion criteria were analysed. Mucinous carcinomas were more common in patients 39 years of age or under (P < 0.005). Most mucinous carcinomas were located in the rectum/rectosigmoid, followed by the right colon; however, the right colon had a higher relative incidence (38 vs 8%, respectively; P < 0.005). Mucinous carcinomas presented at a significantly more advanced stage (23 vs 8%, respectively, stage D disease; P < 0.005) and had a markedly lower curative resection rate (68 vs 84%, respectively; P < 0.05). Following curative resection, mucinous carcinomas tended to have an increased incidence of subsequent distant metastasis (27.8 vs 18.8%, respectively; P < 0.005). The overall survival rate of patients with mucinous carcinoma was worse than that of non-mucinous carcinoma (P < 0.005). Multivariate analysis showed that clinically important predictive factors were stage of disease on diagnosis and subsequent distant metastasis. The mucinous histological type itself was not an independent prognostic factor in colorectal cancer.

Helicobacter pylori in cirrhotic patients with peptic ulcer disease: a prospective, case controlled study

BACKGROUND

There is an increased prevalence of peptic ulcer disease in patients with liver cirrhosis, but the role of Helicobacter pylori is unclear.

METHODS

lgG antibodies against H. pylori were measured in 60 patients with compensated liver cirrhosis, in 60 sex- and age-matched patients with compensated liver cirrhosis, and in 60 normal controls. All patients received panendoscopic examinations to search for the evidence of esophageal varices, congestive gastropathy, and peptic ulcers.

RESULTS

Duodenal ulcers were more common in compensated and decompensated cirrhotic patients (16.7% and 13.3%, respectively) than in normal controls (3.3%, p < 0.05). Gastric ulcers were more frequent in decompensated (15.0%) than compensated cirrhotic patients and normal controls (3.3% and 1.7%, respectively, p < 0.05). The prevalence of H. pylori was not statistically different among the three groups (normal 60.0%, compensated 61.7%, and decompensated, 75.0%; p > 0.05). The prevalence of H. pylori also showed no statistical differences in respect to duodenal ulceration (100%, 80%, and 87.5%, respectively, p > 0.05). The prevalence of H. pylori did not differ significantly in relation to the presence or absence of esophageal varices (68.4% vs 100% if no varices, p = 0.04) and in the presence of congestive gastropathy (50.0 vs 94.7%, p = 0.03).

CONCLUSIONS

The prevalence of peptic ulcer was increased in cirrhotic patients, but the prevalence of H. pylori was similar in compensated cirrhotic patients, decompensated cirrhotic patients, and normal controls. The frequency of non-H. pylori-associated peptic ulcers in cirrhotic patients was increased in the presence of esophageal varices or congestive gastropathy.

Liquid-crystal-based switchable polarizers for sensor protection

Linear polarizers are generally employed in conjunction with advanced liquid-crystal filters for the protection of human eyes and optical sensors. For detection sensitivity under a no-threat condition to be maximized, the polarizer should remain in a clear state with a minimum insertion loss. When threats are present, it should be quickly switched to function as a linear polarizer with a high extinction ratio. Two types of switchable polarizer for sensor protection are demonstrated. The polarization conversion type exhibits a high optical efficiency in its clear state, a high extinction ratio in the linear polarizer state, and a fast switching speed, except that its field of view is limited to approximately ±10°. In contrast, an improved switchable dichroic polarizer functions effectively over a much wider field of view. However, its extinction ratio and optical efficiency in its clear state are lower than those of the polarization conversion type.

Detection and partial sequence analysis of Helicobacter pylori DNA in the bile samples

The existence of Helicobacter pylori in the biliary tract was investigated. Seven bile samples were included in this study. Among them, six bile samples were collected by percutaneous transhepatic cholangiodrainage and the other by needle aspiration during cholecystectomy. Using nested PCR with two sets of primers homologous to the urease A gene, Helicobacter pylori DNA was detected. Three samples, one from a patient with advanced gastric cancer involving the pancreatic head and two from patients with pancreatic head tumor, were found to be positive for Helicobacter pylori DNA. On the other hand, three samples from patients with cholangiocarcinoma and one from a patient with chronic cholecystitis were all negative. To further verify the specificity of our PCR analysis, partial sequences of the PCR products from the three positive samples were analyzed by direct sequencing. Several silent mutations and a missense mutation (AAA to AGA; Lys-164 to Arg-164) were identified in the urease A gene. We conclude that Helicobacter pylori DNA can be easily detected in the bile samples. The possibility of asymptomatic cholangitis caused by this organism requires further investigation.

Emphysematous gastritis secondary to acute gastric dilatation

Emphysematous gastritis is a life-threatening disease. Although rare in incidence, it has a fulminating course with a high mortality rate. A case of a 58 year old male with emphysematous gastritis is reported. Initially, he presented with acute gastric dilatation secondary to anorexia/bulimia-like behaviour. Later, emphysematous gastritis developed. The abdominal sonographic findings, which have not been previously described in the literature, showed intramural gas and gastric wall thickening. After receiving a total gastrectomy, he had a satisfactory outcome. The present report discusses the possible aetiologic relationship between acute gastric dilatation and emphysematous gastritis, and suggests abdominal sonography to be the first choice of diagnostic measure for patients and the intramural gas in the gastric wall. This is the first case of emphysematous gastritis diagnosed by abdominal sonography.

Endoscopic injection sclerotherapy of bleeding duodenal varices

Bleeding from duodenal varices is a rare finding in patients with liver cirrhosis. We report a 43 year old male with alcoholic liver cirrhosis who presented with upper gastrointestinal bleeding. Panendoscopy identified, prominent tortuous varices over the second portion of duodenum with spurting of blood. At first, the varices were treated successfully with sodium tetradecyl sulfate and bleeding stopped. Consequent endoscopic sclerotherapy was done 1 week later. The varices almost disappeared 2 weeks after the second endoscopic sclerotherapy and the patient was in good condition following this.

A prospective study of fungal infection of gastric ulcers: clinical significance and correlation with medical treatment

A prospective study was performed to evaluate the prevalence of fungal infection in gastric ulceration and its effect on ulcer healing in 178 benign and 97 malignant gastric ulcers. Fungal infection was defined as presence of fungal hyphae or spores in the biopsy forceps specimen. For patients with benign gastric ulcers, sucralfate 1 g q.i.d. was prescribed and a second panendoscopy examination was carried out after 6 weeks to evaluate ulcer healing. Fungal colonization was found in 36 (20.2%) patients with benign gastric ulcers and 26 (26.8%) patients with gastric cancers (p > 0.2). The mean age of patients with benign gastric ulcer with fungal infection (group I) was 64.2 +/- 11.4 years, whereas the mean age of those without fungal infection (group II) was 56.2 +/- 13.1 years (p < 0.01). Follow-up panendoscopy after 6 weeks of sucralfate therapy revealed 6 of 24 patients (25%) in group I and 19 of 81 patients (23%) in group II with unsatisfactory healing (difference not significant). Comparison of confounding factors such as smoking, daily tea or coffee intake, underlying disease, ulcer location, and endoscopic appearance between these two groups revealed no significant differences. In conclusion, the presence of fungus in gastric ulcers is a secondary phenomenon and it does not affect ulcer healing.

Acute hepatitis A with coexistent hepatitis C virus infection presenting as a virus-associated hemophagocytic syndrome: a case report

A 23-yr-old male with acute hepatitis A and coexistent hepatitis C became critically ill 3 wk after the onset of fever and jaundice with progressive anemia, thrombocytopenia, and hepatosplenomegaly. Bone marrow biopsy revealed hemophagocytosis. Despite aggressive supportive treatment with parenteral steroids, the patient died of disseminated intravascular coagulopathy with gastrointestinal bleeding. Necropsy of the liver showed histiocyte aggregation in the portal area with hemophagocytosis.

Specific staining of iododeoxyuridine and bromodeoxyuridine in tumors double labelled in vivo: a cell kinetic analysis

The simultaneous and specific staining of iododeoxyuridine (IdUrd) and chlorodeoxyuridine (CldUrd) allows for more accurate estimates of potential doubling time (Tpot). Because CldUrd is not approved for human use, the procedure was adapted for the staining of IdUrd and bromodeoxy-uridine (BrdUrd). The fluorescein isothiocyanate-conjugated B44 antibody (B44-FITC) stained both IdUrd and BrdUrd in tumor nuclei labelled singly with one or the other pyrimidine analogue. However, when MCaK tumors in exponential growth in vivo were pulse labelled with both IdUrd and BrdUrd, the staining of BrdUrd was not seen, and the labelling pattern reflected specificity to IdUrd. These observations were confirmed using tumors pulse labelled with IdUrd and/or BrdUrd at 6 h and/or 0.3 h prior to tumor removal in all possible combinations. Simultaneous specific staining of BrdUrd by Br3 and of IdUrd by B44-FITC was documented by quantification of labelling indices (LIs) from double-labelled tumors. The specificity of B44-FITC for IdUrd in double-labelled tumors was due to a greater affinity of this antibody for IdUrd than for BrdUrd. This technique allowed for two independent estimates of LI and Tpot when tumors were double labelled for 3.0 and 5.5 h. Both IdUrd and BrdUrd are approved for clinical use, and this double-labelling technique should prove to be valuable for measuring the cell kinetics of solid tumors in vivo.

The role of colonoscopy in screening persons with family history of colorectal cancer

First-degree relatives of colorectal cancer patients are at increased risk for developing colorectal neoplasms. In order to assess the potentiality of colonoscopy screening in this high-risk population, 213 asymptomatic family members (age range 30-69 years, mean 42.8 years) of those patients with colorectal cancer received colonoscopic examination at Chang-Gung Memorial Hospital from April 1992 to May 1994. Twenty-eight persons with 42 lesions (polyps or cancer) were identified, including 28 adenomas, nine hyperplastic polyps and five adenocarcinomas. The positive detection rate was 9.9% for adenoma and 2.3% for cancer. Colorectal neoplasms afflicted males more frequently than females (16.7 vs 5.7%, P < 0.05) and occurred less frequently in those < 40 years of age (5.5 vs 17.2%, P < 0.05). Forty-two per cent of the detected neoplastic lesions were beyond the reach of 60 cm flexible sigmoidoscopy and 36% of adenomas were < 0.5 cm in size and would be missed if patients were screened by air contrast barium enema. Cost analysis revealed that the charges of both screening colonoscopy and screening flexible sigmoidoscopy/air contrast barium enema were approximate. Colonoscopy also has a high acceptability and safety. It appears appropriate to use colonoscopy, rather than flexible sigmoidoscopy or air contrast barium enema, as an initial screening procedure for persons with a family history of colorectal cancer, especially those > 40 years of age.

Early gastric cancer--a clinicopathological study

From 1983 to 1991. 981 cases with gastric cancer underwent gastric resection in Chang Gung Memorial Hospital. Ninety-two cases (9.4%) had early gastric cancer with a mean age of 54.5 years. The most commonly present symptoms were epigastralgia and abdominal fullness (79.3%). Most lesions were located in the lower third of stomach (64.0%). Type IIc was the most common macroscopic type (31.5%). The tumor was confined to the mucosa layer in 40 (43.5%) cases; submucosa invasion was noted in the remaining 52 (56.5%) patients. Lymph node involvement was found in 5 (5.4%) cases. No statistical correlation between the depth of tumor invasion and the size of the tumor was noticed. Three patients died of tumor recurrence on the 11th, 13th and 36th months after operation. The Kaplan-Meier estimate for five year survival was 96.4% in these 92 cases. 96.6% in mucosa cancer and 95.6% in submucosa cancer. The risk factor for mortality was lymph node metastasis which had a positive correlation with the depth of tumor invasion. There were four (4.3%) cases of minute early gastric cancer. However, there was neither mortality nor lymph node metastasis in these four cases. Retrospectively, the review of original histological slides in 40 cases, the intestinal type of early gastric cancer had a higher association with intestinal metaplasia, had more frequency of submucosa invasion (70% vs 35%, p = 0.026), and were older in age (61 vs 50.4 years old) than the diffuse type. Although statistically insignificant, the intestinal type had the tendency to involve the lymph node.

Ternary phase and amplitude modulations using a twisted nematic liquid crystal spatial light modulator

Ternary phase and amplitude modulations that use a reflective mode, 45° twisted nematic liquid-crystal spatial-light modulator are demonstrated. This use offers a simple method for implementation of ternary phase-amplitude filters with high resolution, high optical efficiency, and fast response time.

Acute Q fever hepatitis in Taiwan

We report a case of a chronic hepatitis B carrier with an episode of acute hepatitis. The patient presented with a headache, arthralgias, jaundice and fever. While the laboratory tests mimicked chronic hepatitis B with an acute exacerbation, lipogranulomatous changes seen in the liver biopsy strongly suggested the presence of Q fever. Serology testing for Coxiella burneti proved positive and the patient responded to tetracycline therapy. While previously unreported in Taiwan, Q fever is important to consider in an atypical hepatitis presentation because it is a treatable condition.

A clinical study on pseudomyxoma peritonei

To elucidate the clinical entity of pseudomyxoma peritonei, nine patients (male: female = 6:3) who had been treated in Chang Gung Memorial Hospital in the past 13 years were reviewed. The male patients with original appendiceal tumour were older than the male patients with original colon cancer or indefinite tumour (70, 67 and 67 years vs 42, 27 and 50 years). In addition, the former group survived in a disease-free status for 28 months on average, while the latter group died within 2 years. Echogenic ascites and diffuse low-attenuation intra-abdominal masses with scalloping on the surface of liver detected by ultrasonography and by computerized tomography, respectively, were found in most of the patients. Elevation of the serum carcinoembryonic antigen (CEA) during recurrence of the disease was also noted. This series suggested that: (i) the pre-operative diagnosis could be made with careful physical examination in conjunction with sonography or computerized tomography; (ii) the prognosis was better in patients with tumour of appendiceal origin; and (iii) serum CEA might be valuable for early detection of recurrence.

[Clinical observation of Henoch-Schonlein purpura-focus on gastrointestinal manifestation and endoscopic findings]

During the 5.5-year period from January 1988 to June 1993, there were 40 cases of Henoch-Schonlein purpura diagnosed in Chang Gung Memorial Hospital, Taipei. The diagnosis criteria is defined as a typical skin rash, which pathologic examination shows leukocytoclastic vasculitis, accompanied by any two of these major manifestations of the disease, namely gastrointestinal, renal and joint involvement. Their medical records were reviewed with respect to the clinical symptoms, laboratory findings, roentogenologic findings, endoscopic findings, and morbidity. There are 21 women and 19 men with age raging from 10 to 63 years old (mean age 35.9 years old). The male to female ratio was 1:1.1 and about 80% of the patients were at the age of fifteen or older. There was no special season distribution in this series. The main clinical features were purpuric skin rashes, 40 cases (100%), followed by gastrointestinal symptoms, 25 cases (62.5%), renal involvement, 21 cases (52.5%) and joint involvement, 19 cases (47.5%). The major gastrointestinal symptoms were abdominal pain (25 case) and bleeding from gastrointestinal tract (10 cases), and minor symptoms included vomiting (7 cases), diarrhea (1 cases) and acute pancreatitis (2 cases). Gastrointestinal endoscopy was performed in 5 cases and all had hyperemic mucosa and scattered hemorrhagic purpura in the stomach and duodenum. The characteristic hemorrhagic erosive duodenitis were observed in 3 cases. These findings may alert the gastroenterologists to take into consideration of this disease earily and thus avoid unnecessary laparotomy and complications.

Vibrio vulnificus infection--report of 8 cases and review of cases in Taiwan

Vibrio vulnificus infection, which is a rare and fatal disease, can be categorized clinically as either primary septicemia or wound infection. The clinical presentation of patients with primary septicemia can vary from fever alone to a more severe illness including high-grade bullous lesions, hypotension, and shock. Wound infection typically results from either injury to the skin in a marine environment or contact of a preexisting wound with sea water. We reported eight cases with Vibrio vulnificus infection in Chang gung Memorial Hospital and reviewed ten other cases previously reported with details in Taiwan. Fourteen patients presented with primary septicemia, and four with wound infection. Thirteen patients had alcoholism or chronic liver disease, two had peptic ulcer disease, one was steroids abuser, and one patient had thalassemia and chronic liver disease. Overall mortality was 55.6% (ten patients). Patients with hypotension within 48 hours of admission had higher mortality than normotensive patients (77% vs. 0%, P = 0.007). Patients with chronic liver disease or liver cirrhosis also had tendency to a higher mortality than not (64% vs. 25%, P = 0.274). Chronic liver diseases and liver cirrhosis are common disease in Taiwan. They take a high risk for Vibrio vulnificus infection. Clinician should keep in mind of this potentially fatal infection in these patients reporting a history of recent raw oyster consumption and presented with sepsis and characterized skin lesions. Prompt empirical antibiotics treatment and aggressive surgical treatment may be lifesaving for this acute and fatal disease.

Henoch-Schönlein purpura complicated by upper gastrointestinal bleeding with an unusual endoscopic picture

In the course of Henoch-Schönlein purpura, diverse gastrointestinal manifestations are common. We report a patient with Henoch-Schönlein purpura complicated by upper gastrointestinal bleeding. A peculiar endoscopic picture not previously described is presented and articles about the endoscopic findings in this disease are reviewed. It is concluded that endoscopy can be useful in the diagnosis of Henoch-Schönlein purpura, especially for those patients without typical skin rash.

Pancreatic tuberculosis mimicking pancreatic head carcinoma: a case report and review of the literature

A 24-year-old man presented with vague abdominal fullness and a mild epigastric dull pain for about 3 months was found to have a pancreatic head tumor at a medical center 2 months ago. He came to our hospital for further treatment. Ultrasonography, endoscopic retrograde cholangiopancreatography (ERCP) and abdominal computed tomography (CT) all revealede a pancreatic head tumor. Laparotomy was performed because pancreatic head carcinoma was highly suspected. Indurated mass in the pancreatic head, enlarged lymph nodes and white tubercles on the intestine proved to be tuberculosis on histological examination of a frozen section. Acid fast bacilli were also found. The patient was given antituberculous therapy and is now doing well. To avoid unnecessary laparotomy, CT, echo-guided percutaneous aspiration cytology or biopsy and culture of the tissue for mycobacteria should be done in a patient with pancreatic mass, especially in a region where pulmonary and abdominal tuberculosis are common.