Mutation analysis of the APC gene in Taiwanese FAP families: low incidence of APC germline mutation in a distinct subgroup of FAP families

Familial adenomatous polyposis (FAP) is an autosomal-dominant disease caused by germline mutations in the adenomatous polyposis coli (APC) gene. The affected individuals develop colorectal polyposis and show various extra-colonic manifestations. In this study, we aimed to investigate the genetic and clinical characteristics of FAP in Taiwanese families and analyze the genotype-phenotype correlations. Blood samples were obtained from 66 FAP patients registered in the hereditary colorectal cancer database. Then, germline mutations in the APC genes of these 66 polyposis patients from 47 unrelated FAP families were analyzed. The germline-mutation-negative cases were analyzed by performing multiplex ligation-dependent probe amplification (MLPA) and single-strand conformation polymorphism (SSCP) analysis of the MUTYH gene. Among the analyzed families, 79% (37/47) of the families showed 28 APC mutations, including 19 frameshift mutations, 4 nonsense mutations, 3 genomic deletion mutations, 1 missense mutation, and 1 splice-site mutation. In addition, we identified 15 novel mutations in 32% (15/47) of the families. The cases in which APC mutations were not identified showed significantly lower incidence of profuse polyposis (P = 0.034) and gastroduodenal polyps (P = 0.027). Furthermore, FAP families in which some affected individuals had less than 100 polyps showed significant association with low incidence of APC germline mutations (P = 0.002). We have added the APC germline-mutation data for Taiwanese FAP patients and indicated the presence of an FAP subgroup comprising affected individuals with nonadenomatous polyps or less than 100 adenomatous polyps; this form of FAP is less frequently caused by germline mutations of the APC gene.

Mismatch repair protein expression in Amsterdam II criteria-positive patients in Taiwan

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is characterized genetically by germline mutations in DNA mismatch repair (MMR) genes. Immunohistochemistry (IHC) has high sensitivity and specificity for identifying MMR-deficient tumours. This study investigated the clinical presentations and frequency of HNPCC in Taiwan by combined Amsterdam II criteria (AC-II) and IHC.

METHODS

In 1995-2003, 7108 patients with primary colorectal cancer registered in Chang Gung Memorial Hospital's Colorectal Cancer Registry were screened using AC-II. Tumour specimens were analysed for MMR protein expression by IHC, and relevant clinicopathological details were documented.

RESULTS

Some 83 patients fulfilled the AC-II. Clinicopathologically, 43 patients (52 per cent) had proximal tumours, ten (12 per cent) had poorly differentiated cancers, 17 (20 per cent) had mucinous adenocarcinoma and 51 (61 per cent) had stage I-II tumours. Seventeen patients developed second primary colonic and extracolonic cancers over a mean 7.2-year follow-up. Immunohistochemically, 58 patients were MMR protein deficient. They had a significantly earlier age of onset (P < 0.001), more proximal tumour location (P = 0.002), less advanced tumour stage (P = 0.008) and more second primary cancers (P = 0.017) compared with MMR-competent patients.

CONCLUSION

These data show significant differences in clinical features between MMR protein-deficient and MMR competent subgroups.

Porous polymer films and honeycomb structures based on amphiphilic dendronized block copolymers

Fabrication of honeycomb patterned films from our synthesized amphiphilic dendronized block copolymer by "on-solid surface spreading" method and "on-water spreading" method was reported for the first time in this paper. The comparison of the two methods indicated honeycomb-patterned films with smaller size, and larger surface density of micropores can be fabricated by spreading on water but with lower regular arrangement. Furthermore, several influencing factors on the formation of the honeycomb structure and the different morphologies, such as the concentration of the copolymer solution and the relative humidity in the atmosphere and the substrates, were investigated. The results showed that comparably high relative humidity from 80% to 95% was needed, and the mica plate as a spreading substrate was suitable to form orderly porous films for such a copolymer. The best ordered pattern could be formed from the copolymer with concentration of 1.00 mg/mL at the relative humidity of 85% using a mica plate. Besides, strong periodicity, regularity, and a large, defect-free area were notable, which made this structure extremely interesting for applications for templated molecular objects formed via intramolecular metal or metal oxide synthesis.

Predictive value of serum thymidine kinase level for Ig-V mutational status in B-CLL

In B-CLL IgV(H) genes mutational status is a major prognostic factor. Since sequencing of IgV(H) genes is not available in most laboratories, an easily performed surrogate assay is desirable. To identify the best surrogate assay, and to better discriminate prognostic subgroups we analyzed clinical and biological data from 58 typical CLL cases. A higher serum thymidine kinase level (>15 U/l) proved to be a strong predictor of mutational status, and the only independent one among the studied parameters. To further identify prognostic subgroups, cluster analysis was employed on 38 cases on which all data were available, which segregated two groups including 25 and 13 patients, respectively. These two clusters differed by their proliferative potential and appeared to discriminate patients with very different clinical course and outcome. s-TK was strikingly different among these two clusters, suggesting that s-TK level could be used routinely to identify patients at risk of progression.

Apigenin inhibits endothelial-cell proliferation in G(2)/M phase whereas it stimulates smooth-muscle cells by inhibiting P21 and P27 expression

Apigenin is a plant flavonoid that is thought to play a role in the prevention of carcinogenesis. However, its mechanism of action has not yet been elucidated. Because of the importance of angiogenesis in tumor growth, we investigated the effect of apigenin on endothelial and smooth-muscle cells in an in vitro model. Apigenin markedly inhibited the proliferation, and, to a lesser degree, the migration of endothelial cells, and capillary formation in vitro, independently of its inhibition of hyaluronidase activity. In contrast, it strongly stimulated vascular smooth-muscle-cell proliferation. The molecular mechanisms of apigenin activity were analyzed in these 2 types of cells. Our results show that apigenin inhibits endothelial-cell proliferation by blocking the cells in the G(2)/M phase as a result of the accumulation of the hyperphosphorylated form of the retinoblastoma protein. Apigenin stimulation of smooth-muscle cells was attributed to the reduced expression of 2 cyclin-dependent kinase inhibitors, p21 and p27, which negatively regulate the G(1)-phase cyclin-dependent kinase.

Changes in protein sulfation in human erythroleukemia (HEL), CHRF-288-11, and K562 cells following treatment with dimethyl sulfoxide or phorbol 12-myristate 13-acetate

This study has demonstrated that three hematopoietic tumor cell lines with megakaryocytic characteristics, HEL, CHRF-288-11, and K562, synthesize a number of sulfated proteins. The major HEL sulfated proteins were a doublet at 88 and 92 kDa and several closely spaced bands between 125 and 160 kDa and more acidic proteins of 210 kDa. Treatment with dimethylsulfoxide (DMSO) for 24 h almost completely inhibited labeling of sulfated proteins, and up to 48 h, labeling was found almost entirely in a band at 125 kDa. Treatment with phorbol 12-myristate 13-acetate (PMA) nearly eliminated labeling of the 88- and 92-kDa bands and resulted in the appearance of a large amount of labeling between 96 and 108 kDa. Sulfated proteins of 135 and 210 kDa were immunoprecipitated by an antibody against platelet GP Ib. A 130-kDa protein was immunoprecipitated by an antibody against the beta-1 integrin subunit. The major proteins labeled in CHRF cells were at 68, 90, 98, 125, and 148 kDa. Treatment with PMA greatly reduced the labeling of the 148-kDa band, eliminated the labeling of the 68-kDa band, and markedly enhanced labeling of the 92-kDa region. The major proteins labeled in K562 cells were at 110, 120-130, and 145 kDa. PMA reduced the labeling of the 110- and 145-kDa proteins and extensively increased labeling of bands at 120-130, 78, and 84 kDa, and DMSO caused decreased labeling of the 120- to 130-kDa proteins. This is the first demonstration of sulfation of specific proteins in hematopoietic cell lines and of the alteration of sulfation of specific proteins in any cells in response to treatment with differentiation-inducing agents. We hypothesize that changes in sulfation of proteins may be relevant to the maturation or malignant growth of megakaryocytic cells.

Solid and papillary neoplasm of the pancreas. Emphasis on surgical treatment

Six Chinese females with solid and papillary neoplasms of the pancreas underwent surgery. Mean age was 26 years. The most common clinical sign was a large palpable abdominal mass. One patient presented with shock and acute onset of abdominal pain with positive peritoneal signs due to rupture of the tumor. The surgical procedures included Whipple's operation in one patient with a tumor at the head of pancreas, a 75% distal pancreatectomy in two patients with tumor of the body or tail of the pancreas, a partial pancreatectomy and pancreaticogastrostomy in one patient with a tumor at the neck and body of the pancreas, total excision in one patient with a tumor of the body of the pancreas, and a Roux-en-Y cystojejunostomy in one patient with a huge unresectable tumor of the head and body of the pancreas. During the follow-up period of from 40 to 83 months, four patients had survived and two had died of causes unrelated to the tumor in the differential diagnosis of a pancreatic mass, especially in young women with long histories of epigastric masses. Resection is the treatment of choice when the tumor is resectable. For unresectable tumors, a bypass procedure might be an alternative.

[The clinic diagnostic value of the rigid sigmoidoscopy]

Rigid sigmoidoscopy is beneficial as it detects rectal or distal sigmoidal lesions very efficiently and precisely. But it also has some complications, e. g. rectal injury, rectal perforation or transient bacteremia. In this prospective study, 800 cases were collected and divided into two groups. In group I, 400 O.P.D. symptomatic cases were chosen randomly and in group II 400 cases registered for routine physical examination were picked up. The positive detection rate was 7% in group I versus 2% in group II. The lesions detected in group I are 15 cases of cancer, 7 cases of polyp, 4 cases of irradiation proctitis, 2 cases of ulcerative colitis and 1 case of pseudomembranous colitis. Only 8 polyps are found in group II. The routine sigmoidoscopy is mandatory for symptomatic patients but it is not cost-effective for routine check-ups. The stool occult blood is the best screening test for detecting colorectal lesions. For routine physical examination, stool occult blood test is safe and easy to perform. If the stool occult blood test is positive, then further examinations will be necessary.

The role of lasers in hemorrhoidectomy

Eighty-eight patients who received treatment for hemorrhoids were randomized into two groups. Group A received the Nd-YAG laser phototherapy for internal hemorrhoid combined with the CO2 laser for external hemorrhoid. Group B was treated with closed Ferguson hemorrhoidectomy. The need of narcotic injections for pain relief was 11 percent in group A vs. 56 percent in group B (P less than 0.001). The incidence of postoperative urinary retention was 7 percent in group A, vs. 39 percent in group B (P less than 0.05). No enema was required postoperatively in group A, vs. 9 percent in group B; 84 percent of the patients in group A were discharged on the second postoperative day, vs. 83 percent of the patients in group B discharged on the fifth postoperative day. The cost was 20 percent less in the former group. The overall complications in both groups were insignificant in difference, except prolonged wound healing in group A was noted. One year follow-up showed satisfactory results. Laser treatment is considered one of the alternatives to conventional treatment, but the surgeon needs to be aware of laser hazards.

Perianal Paget's disease--report of 4 cases

Over the past nine years (from 1981 to 1989), four patients with perianal Paget's disease were treated. All were male with an average age of 58.5 years. Clinically, perianal Paget's disease manifests as a slowly enlarging eczematous, and sharply demarcated perianal skin rash that may be oozing or itching. In the characteristic pathology finding, Paget's cells appear as large, rounded signet-ring cells with abundant mucin stain positive cytoplasm in the basal layer of the acanthotic epidermis. All but one, who suffered from primary sweat gland carcinoma, had underlying rectal adenocarcinoma. The first two cases expired soon after a delayed diagnosis of terminal underlying malignancy. Only in the later two cases was there a preoperative suspicion of perianal Paget's disease. There is often a delay in diagnosis due to clinical ignorance. Patients with persisting perianal skin rash should be biopsied frequently. If perianal Paget's disease is diagnosed, the underlying malignancy should be surveyed and managed thoroughly.

Oncogene amplification correlates with dense lymphocyte infiltration in human breast cancers: a role for hematopoietic growth factor release by tumor cells?

One hundred six primary breast cancer samples were analysed for c-erbB2, int-2, and c-myc gene amplification. Surgically confirmed nodal involvement was observed in 42%. Level of gene amplification was studied by Southern and/or slot blot techniques. Amplified c-erbB2 gene sequences were present in 21.5% of all samples. Int-2 was amplified in 13.1% and c-myc was amplified in 10.3%. In a non-parametric test (Kruskal-Wallis) a strong negative association was found between high levels of c-erbB2 amplification and absence of estrogen receptor (ER) (P = .0009) or progesterone receptor (PR) (P = .011) expression. No correlations were found between all or high levels of amplification of each oncogene separately or combined with T, N, grade, multifocality of tumor, or associated carcinoma in situ. There was a trend approaching statistical significance for patients with c-erbB2 amplifications to have positive lymph nodes at surgery (P = 0.09). A somewhat surprising finding however was a very strong association between oncogene amplification and dense lymphocyte infiltration of the tumor (P = .05). This correlation is even stronger when only high levels of amplification are considered, either for each oncogene separately (P = .0048) or in combination (P = .0007). We propose that malignant cell cytokine production may help explain this observation.

[Etiology of intestinal obstruction--4 years' experience]

In order to find out the etiological patterns of intestinal obstruction, we reviewed 1205 cases diagnosed as intestinal obstruction at our hospital. The operative findings, locations of obstruction and pathological results were analyzed among 707 cases who were operated on. The most common cause of colon obstruction was tumor (78.7%). The etiologies of small intestinal obstruction were: adhesions, 47.4%; hernia, 22.1%; tumor, 11.8%; intussusception, 8.8%; foreign bodies, 3.7%; and miscellaneous causes, 6.2%. In the patients older than 40 years, the most common causes of intestinal obstruction were adhesion and malignancy, in contrast to hernia and intussusception that were commonly found in children. The mean age of the patients with colon obstruction was older than those with small bowel obstruction, 55.7 +/- 21. vs 39.4 +/- 17.3 (P less than 0.001). Of the patients with previous abdominal surgery, adhesions caused the obstruction in up to 60.5%. Among the 102 cases who had been operated for abdominal malignancy, the cause of intestinal obstruction was due to recurrent tumor in 78 patients (76.4%). Of patients without previous abdominal surgery, the etiologies of intestinal obstruction were: incarcerated hernia, 36.7%; tumor, 21.1%; intussusception, 15.6%; and adhesion, 13.8%. The incidence of strangulation obstruction was 25.7%, of which the major causes were adhesions, 51.7%; and hernia. 43.0%. We concluded that the most common cause of colon obstruction was tumor. The two most common causes of small intestinal obstruction were adhesions and hernia. Age and past history of abdominal surgery can much help for the differential diagnosis.

Non-traumatic perforation of colon and rectum

Free perforation of the colon and rectum is an acute surgical condition. Possible factors affecting the prognosis include age, sex, underlying disease, surgical procedures, duration from onset to surgical treatment, general condition before surgery and degree of contamination. A series of 50 cases with acute, nontraumatic perforation of the colon and rectum treated at Chang Gung Memorial Hospital from 1979 to 1986 were reviewed and studied retrospectively according to these prognostic factors. The mortality rate was highest in the group with colo-rectal cancer (45%). The mortality rate was 50% in the group who underwent primary closure with proximal diversion and 40% in the group who underwent resection without anastomosis. The mortality may not be related to the surgical procedure: the selection of the procedure was based on the seriousness of the illness. The mortality rate was 87% in patients with septic shock, 62% when treatment was delayed for more than 72 hours, 72% with severe contamination and 56% with poor nutritional status. Age, sex and underlying diseases were not significant contributing factors.