Heat shock and cytokines modulate the expression of adhesion molecules on different human gastric-cancer cell lines

In order to understand the expression and modulation of adhesion molecules (AMs) on the surface of different gastric cancers, we studied 4 gastric-cancer cell lines including SC-M1, KATO-III, AGS and AZ-521. The expression of E-cadherin, integrins (beta1, beta2 and beta3), ICAMs (1 and 2), and CD11 (a, b and c) on the cells was detected by flow cytometry. We found that E-cadherin was only expressed on SC-M1 and KATO-III. CD29 (beta1 integrin) could be found in cells of all 4 lines. CD54 (ICAM- 1) could not be detected in AZ-521. In contrast, CD18 (beta2 integrin), CD61 (beta3 integrin), ICAM-2, CD11a, CD11b and CD11c were all absent from these cells. Heat-shock treatment (42.5 degrees C, 60 min) enhanced the expression of E-cadherin, CD29 and CD54 on SC-M1, and of CD29 on AGS. In addition, TNF-alpha (50U/ml) and IL-1beta (10U/ml) modulated the expression of these AMs, like heat-shock treatment. The increment of these adhesion molecules caused by heat shock, TNF-alpha and IL-1beta stimulation on SC-M1 was also confirmed by Western blot analysis. Functionally, these treatments increased the binding between normal human mononuclear cells and SC-Ml cells. The heat-shock treatment could induce a significant amount of TNF-alpha and IL-1beta release from SC-M1 and KATO-III, but seemed irrelevant to the expression of AMs. These results suggest that limited adhesion molecules were expressed on the surface of different gastric cancer cells. Heat shock, IL-1beta and TNF-alpha may selectively modulate the expression of these 3 molecules on some of the cells, and this is probably related to their antitumor effect.

Surgical management of primary retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcoma is a rare and challenging group of diseases for surgeons, characterized by extensive growth and high recurrent rate. We analyzed data from our patients to identify the factors of survival.

METHODS

From 1971 to 1993, medical records of 40 patients with primary retroperitoneal sarcoma were reviewed. Clinical factors including age, sex, tumor size, histopathology, type of operation, disease-free interval, and number of operation were collected to correlate with patient's survival.

RESULTS

Most patients presented with huge abdominal mass. There were 22 liposarcomas, 8 leiomyosarcomas, 5 malignant fibrous histiocytomas, 2 fibrosarcomas, 2 malignant mesenchymomas and one rhabdomyosarcoma. Twenty-eight patients received complete resection and 12 had incomplete resection. The group with complete resection showed a better survival than incomplete resection group (p = 0.0001). Nineteen patients with complete resection had tumor recurrence. The recurrent rate was 68%. Patients having been disease-free for more than 12 months showed to have better survival than those less than 12 months (p = 0.005). Aggressive surgical resection was done in case of tumor recurrence. Patients who received more than 2 (> or = 3) operations also showed a better survival than those with less than 2 operations (p = 0.0247).

CONCLUSIONS

Complete surgical resection and aggressive repeated surgical intervention are the most effective treatment modality for better survival in patients with retroperitoneal sarcoma.

Results of curative gastrectomy for carcinoma of the distal third of the stomach

BACKGROUND

Carcinoma of the distal stomach metastasizes to lymph nodes along the bile duct, pancreatic head, and duodenum. We reviewed the results of patients who underwent operation for carcinoma of the stomach, and placed special emphasis on survival related to lymph node metastasis.

STUDY DESIGN

We conducted a prospective study of 258 consecutive patients with adenocarcinoma of the distal third of the stomach who underwent curative gastrectomies.

RESULTS

Most of the patients (193 [75 percent]) had advanced cancer (extension beyond the submucosa). A subtotal gastrectomy was the procedure most commonly performed (89 percent). Combined organ resection was performed in 100 patients (39 percent). The operative morbidity was 17 percent; the most frequent complications were chylous leakage, anastomotic insufficiency, and intra-abdominal infection. Ninety-four patients (36 percent) had tumor recurrence, with local recurrence occurring in 45 patients. In 40 of the 45 cases, the local recurrence resulted from remnant lymph nodes (LNs), or soft tissues in the gastric bed. Lymph node metastases were observed in 152 patients (59 percent). Excluding five patients (2 percent) who died, the overall five-year cumulative survival rate was 53 percent. The five year survival rate was 98 percent for patients with TNM stage I disease; 68 percent for patients with stage II disease; 40 percent for patients with stage III disease; and 10 percent for patients with stage IV disease. The survival rate for patients with n0, n1, n2, and n3 disease was respectively 92 percent, 45 percent, 30 percent, and 20 percent. For patients with metastatic LNs in the hepatoduodenal ligament, the five-year survival rate was 20 percent.

CONCLUSIONS

These data suggest that survival rate relates to the extent of LN metastasis. It appears that systematic lymph node dissection may have a beneficial effect. However, the efficacy of radical lymph node dissection can only be determined by prospective, randomized clinical trials with a proper study design.

The surgical treatment and prognostic factors of well-differentiated thyroid cancers in Chinese patients: a 20-year experience

BACKGROUND

Well-differentiated thyroid cancers (WDTC) are usually slow-growing neoplasm with an indolent clinical course. Assessment of treatment modalities for them requires a long-term follow-up in a large population, and is still of much debate. A systematic analysis of the history, prognosis and therapy for this disease in Taiwan is lacking.

METHODS

A retrospective analysis of clinical and pathological records was conducted on 488 patients (149 male and 339 female, male: females = 1:2.28) treated for WDTC in the Veterans General Hospital-Taipei from 1971 to 1991 with subsequently follow-up until December 1994 (Mean follow-up: 8.5 years). Factors influencing recurrence, survival and different treatment were analyzed.

RESULTS

Papillary thyroid cancer increased obviously as compared to our experience from 1959-1976. Changing tumor behaviors, including increasing female/male ratio, higher percentage of papillary cancer, decreasing primary tumor size and lower distant metastatic rate at the time of initial diagnosis, were noted. Factors influencing survival, as determined by univariate analysis, included age, gender, distant metastasis, extrathyroidal invasion, tumor size, nodal involvement, histological type, extent of surgical therapy and use of postoperative radioactive iodine. Those patients aged more than 45 at initial diagnosis, with primary tumors larger than 4 cm, with extrathyroidal invasion, and with distant metastasis at initial diagnosis were classified as being at high risk. The others were at low risk. Total or near total thyroidectomy (TTx), depending on the judgement of each surgeon, had much higher complication rate than lobectomy with/without isthmusectomy, but offered no benefit effect on disease-free survival or overall survival rates. Postoperative radioactive iodine ablation treatment and thyroxine replacement in suppressive dose after TTX improved survival among high risk patients. Lobectomy with/without isthmusectomy in low risk patients, followed by thyroxine suppression therapy, was adequate to improve the postoperative outcome and with low complication rate. Lymph node resection in patients with clinically palpable nodes improved longterm prognosis.

CONCLUSIONS

Changing tumor behavior of WDTC leading to favorable prognosis has been noticed since 1971. Total or near total thyroidectomy is worthwhile in high risk patients with WDTC but does not appear necessary in low-risk patients. Lymph node dissection for metastatic lymph node could improve the survival rate.

Immunohistochemical study of arginase in cancer of the stomach

High levels of arginase have been detected in gastric adenocarcinoma. To examine the hypothesis that this is due to macrophage infiltration into the tumour, we localized the cellular distribution of arginase by immunohistochemical staining. We examined gastric adenocarcinomas and their corresponding normal tissues (n = 45), leiomyomas (n = 2), leiomyosarcomas (n = 3), human gastric adenocarcinoma cell lines (n = 3), and benign gastric ulcers (n = 4) by the avidin-biotin-peroxidase complex technique. Macrophages with strong arginase immunoreactivity were observed infiltrating both gastric normal and cancer tissues. No arginase immunoreactivity was observed in normal mucosal gland, muscular and serosal tissues or benign gastric ulcers. The immunoreactivity of arginase was positive but heterogeneous in most specimens of gastric adenocarcinoma (62.2%) and was absent from gastric intestinal metaplasia, leiomyomas and leiomyosarcomas. Among the 28 neoplasms with arginase immunoreactivity, scattered immunoreactivity was also noted in adjacent dysplastic glands in 12 (42.8%) specimens. Arginase immunoreactivity was observed in all three gastric cancer cell lines. Arginase is present in the cytoplasm but not in the nucleus. These data suggest that the high arginase levels in adenocarcinoma cancer tissues originate largely from cancer cells.

Serum interleukin-6 levels reflect disease status of gastric cancer

OBJECTIVES

Interleukin-6 (IL-6) has been shown to be associated with cancer development. However, its role in gastric cancer patients has never been investigated. Our intent was to investigate this role.

METHODS

Using enzyme-linked immunosorbent assay, we determined the IL-6 levels in sera of patients with gastric cancer (n = 218), benign gastric lesions (n = 9), and hepatitis B (n = 9), and in normal subjects (n = 85). C-reactive protein (CRP) levels and Helicobacter pylori antibodies were simultaneously determined in 150 and 133 gastric cancer patients, respectively. Serial serum IL-6 levels were also measured in 14 gastric cancer patients. Six gastric cancer cell lines were examined for IL-6 secretion. For comparison, serum carcinoembryonic antigen levels in all gastric cancer patients were also determined.

RESULTS

Mean IL-6 levels were significantly higher in patients with gastric cancer (10.0 +/- 9.5 pg/ml) than in patients with benign gastric lesions (2.6 +/- 0.5 pg/ml), in hepatitis B carriers (2.8 +/- 0.9 pg/ml), and in normal subjects (2.5 +/- 0.3 pg/ml). Gastric cancer patients with IL-6 > 10 pg/ml increased in a stage-related manner (p = 0.0001). Serum IL-6 levels increased when four patients had recurrence, whereas IL-6 levels decreased in 10 patients with a disease-free status after gastric resection. Serum IL-6 levels correlated moderately with serum CRP levels (r = 0.5, p < 0.01), but not with H. pylori antibody titers (p = 0.23). Serum IL-6 levels correlated with survival, but not as an independent prognostic indicator. Conversely, patients with CEA > 5 ng/ml increased in a stage-related manner, but this is not an effective reflection of disease progression. Five of six gastric cancer cell lines secrete IL-6.

CONCLUSIONS

Serum IL-6 levels correlate with disease status of gastric cancer and may be used as a new tumor marker for monitoring treatment and response of gastric cancer patients.

Paclitaxel-induced apoptosis in human gastric carcinoma cell lines

BACKGROUND

Gastric cancer is one of the most common cancers in Asia. Chemotherapy and radiation therapy have had limited success. Recently, paclitaxel has been found to be effective against a variety of cancers, including lung, breast, ovary, melanoma, and prostate. Whether paclitaxel is effective in the treatment of gastric cancer is not known and is worthy of investigation.

METHODS

Human gastric carcinoma cell lines NUGC-3 and SC-M1 were examined for response to paclitaxel treatment. Cancer cells were treated with paclitaxel (0.001, 0.01, 0.1, and 1 microM) for 1-3 days. Cell number was counted by hemocytometer and cell viability was determined by the trypan blue exclusion method. Cell cycle progression and expression of proliferating cell nuclear antigen (PCNA) were examined by flow cytometry. The percentage of apoptotic cells was determined after staining with hematoxylin and eosin.

RESULTS

Paclitaxel was cytotoxic to the two human gastric carcinoma cell lines examined. The growth-inhibiting dose was 0.01 microM. Paclitaxel-treated gastric carcinoma cells were arrested mainly in G2/M phases before apoptosis. However, treatment with 0.01 microM of paclitaxel resulted in a decrease of cells at G0/G1 phases without an increase of cells at G2/M phase indicating that paclitaxel was also cytotoxic to gastric carcinoma cells at G0/G1 phases. In addition, the expression of PCNA was significantly increased in 0.1 and 1 microM paclitaxel-treated cells, suggesting that DNA repair was increased in these cells.

CONCLUSIONS

Paclitaxel is effective in growth inhibition of gastric carcinoma cell lines in clinically attainable concentrations. Our results suggest that paclitaxel is a potential chemotherapeutic drug for gastric carcinoma.

Relationship between age and clinical characteristics of patients with gastric cancer

The relationship between the prognosis and age of patients with gastric cancer is controversial. To evaluate whether there is a biological characteristic specific to the age of patients, we examined the clinical characteristics of patients with gastric cancer with special reference to their age. Based on a prospective database, a retrospective study of 419 patients who underwent radical gastrectomy for cure in the past 6 years was conducted. Clinical characteristics including gender, gross appearance of the tumour (Borrmann's classification, tumour location), histopathology (depth of tumour invasion, lymph node status, Lauren's classification and degree of tumour cell differentiation) and TNM tumour stage were analysed in six different age groups (< 39, 40-49, 50-59, 60-69, 70-79, > 80 years). The mean age of the 419 patients was 64.6 years (range from 26-91) and the peak age incidence of gastric cancer (46.3%) was in the 60-69 year old age group. The male: female ratio was 4.6:1 on the whole and male gender predominated at ages > 60. The proportion of diffuse type tumours (68.4%) by Lauren's criteria in the young age group (< 39 yrs) decreased with age (25% in the > 80 years group; P < 0.001). Similarly, the proportion of poorly-differentiated tumours (89.5%) in the young age group (< 39 yrs) decreased with advancing age (P < 0.001). These findings suggest that both diffuse type and poorly-differentiated tumours predominate in younger patients and, without considering the factor of delay in diagnosis, may explain the poorer prognosis demonstrated in younger patients.

Malignant familial hypertrophic cardiomyopathy in a family with a 453Arg-->Cys mutation in the beta-myosin heavy chain gene: coexistence of sudden death and end-stage heart failure

Recent genotype-phenotype correlation studies in familial hypertrophic cardiomyopathy (FHC) have revealed that some mutations in the beta- myosin heavy chain (BMHC) gene may be associated with a high incidence of sudden death and a poor prognosis. Coexistence of sudden death and end-stage heart failure in several families with FHC has recently being reported; however, the genetic basis of such families has not been clearly demonstrated. A three-generation Chinese familial hypertrophic cardiomyopathy (FHC) family (family HLI) with two cases of end-stage heart failure and three cases of sudden death was analyzed. The average age of death in the affected members in this family was 34 years old. Genetic linkage analysis using polymorphisms in the (alpha- and beta-myosin heavy chain genes revealed that FHC in this family is significantly linked to the BMHC gene without recombinations. Single-strand conformation polymorphism analysis of exons 8, 9 and 13 to 23 in the BMHC gene showed a polymorphic band on exon 14 that is in complete linkage with the disease status in this family. DNA sequencing analysis in the affected members revealed an 453Arg-->Cys mutation in the BMHC gene. To our knowledge this is the first reported mutation of FHC in Chinese. Our data suggest that the 453Arg-->Cys mutation is associated with a malignant clinical course in FHC due not only to sudden death but also to end-stage heart failure.

Relation of number of positive lymph nodes to the prognosis of patients with primary gastric adenocarcinoma

BACKGROUND

No nodal grouping category of gastric cancer has been universally accepted for the grading of the effectiveness of therapeutic regimens.

AIMS

To establish an appropriate nodal grouping as a forecaster of distant disease and test its validity as a determinant in survival.

PATIENTS

Five hundred and ten patients who underwent curative resections for gastric cancer were studied.

METHODS

Retrospectively analyse the prognostic significance of the number of metastatic lymph nodes.

RESULTS

A total of 17 176 lymph nodes with an average of 34 per specimen were removed, of which 2811 (16%) showed metastases. Among the 510 patients, 287 (56%) had lymph node metastases, with an average of 9.8 per metastatic case. The survival of all patients was related to their nodal status, an abrupt decrease in survival was seen between 0 and 1 and 4 compared with 5 or more modes while little difference in survival existed among 1, 2, 3, and 4, and among 5, 6, 7, and 8 positive nodes. Multivariate analysis showed that the number of positive nodes (1-4, 5-8 versus > or = 9; relative risk 2.2) and depth of cancer invasion (three levels; relative risk 1.9) were independently correlated with survival. The current nodal stage was not a prognostic factor.

CONCLUSIONS

Gastric cancer patients with 0, 1 to 4, 5 to 8, and > 9 positive nodes may represent four appropriate prognostic groups and should be adopted for classification of nodal stage in gastric cancer.

Mapping the locus for familial hypertrophic cardiomyopathy to chromosome 11 in a family with a case of apical hypertrophic cardiomyopathy of the Japanese type

To identify the disease locus of familial hypertrophic cardiomyopathy (FHC) in a Chinese family, a genetic linkage study was performed using polymorphisms from various chromosomal regions. This family has eight affected members, including a case with typical features of apical hypertrophic cardiomyopathy of the Japanese type. The results revealed significant evidence of linkage of polymorphisms on chromosome 11p13-q13 and FHC in this family with a maximal lod score of 3.38 at theta = 0.00. Our data suggest that the locus responsible for FHC in this family maps to chromosome 11 and that the molecular basis of FHC in the case of apical hypertrophic cardiomyopathy of the Japanese type might be similar to that of other affected members in the same family. Further studies are needed to elucidate the whole spectrum of the genetic basis of apical hypertrophic cardiomyopathy of the Japanese type.

An alternative approach of choledocholithotomy via laparoscopic choledochotomy

OBJECTIVE

To evaluate the safety and feasibility of laparoscopic choledocholithotomy via choledochotomy for the treatment of choledocholithiasis.

DESIGN

A prospective series of 1332 consecutive patients who underwent laparoscopic cholecystectomies, with a mean follow-up of 21.2 months.

SETTING

University-affiliated referral center.

PATIENTS

Forty-three patients (3%) with documented common bile duct stones from January 1991 to February 1995.

INTERVENTIONS

Laparoscopic choledocholithotomy with choledochotomy and T tube drainage were performed in 40 patients. Postoperative endoscopic sphincterotomy after laparoscopic cholecystectomy was performed in three patients.

MAIN OUTCOME MEASURES

Documented removal of common bile duct stones and procedure-related complications.

RESULTS

Laparoscopic choledocholithotomy via choledochotomy was successful in 35 (88%) of 40 patients in whom this procedure was attempted. The mean (+/- SD) operation time was 191.3 +/- 75.4 minutes, and the mean (+/- SD) length of postoperative stay was 10.4 +/- 2.7 days. Seven complications (18%) were recorded, including three major complications (8%) and two retained stones (5%).

CONCLUSIONS

Laparoscopic choledocholithotomy via choledochotomy can be performed safely, without increasing the morbidity rate as compared with that of open choledocholithotomy. Thus, some of the advantages of minimally invasive surgery are preserved.

Mucin mRNA expression in lung adenocarcinoma cell lines and tissues

The expression pattern of mucin genes was studied in 7 lung adenocarcinoma cell lines (CL1, CL2, CL3, NCL2, PC9, PC13, PC14) and 12 lung adenocarcinoma tissues. CL1 and PC13 are poorly differentiated cell lines with low mucin glycoprotein production. The other 5 cell lines are well differentiated and produce a higher amount of mucins. Total RNA was extracted from these cell lines. Northern blot analysis was performed by hybridization with specific antisense oligonucleotide probes recognizing mucin-specific tandem repeats of 4 mucin genes (MUC1, MUC2, MUC3, MUC4). RT-PCR was carried out to amplify the 3' and 5' nonrepetitive coding regions of MUC1 and the 5' nonrepetitive coding region of MUC2. All these cell lines expressed MUC1, MUC2, and MUC4 mRNA but in variable mounts. The poorly differentiated cell lines (CL1 and PC13) had a relatively low level of expression of MUC1, MUC2, MUC3 and MUC4. RT-PCR, with primers amplifying the MUC1 nonrepetitive coding region 5' end, 293 bp, and the 3' end, 522 bp, as well as the MUC2 nonrepetitive 5' coding region, 308 bp, revealed the presence of MUC1 and MUC2 mRNA in all the cell lines. Sequence analysis of the PCR products were very homologous, similar to previously published MUC1 and MUC2 cDNA sequences. The expression pattern of mucin genes is consistent with that of mucin glycoproteins as studied using biochemical and immunological methods. Northern blotting and RT-PCR analysis in 12 lung adenocarcinoma tissues with various grades of differentiation (6 poorly differentiated adenocarcinomas and 6 moderately to well-differentiated adenocarcinomas) showed heterogeneous expression of the 4 mucin genes in tissues without clear correlation with the differentiation grade. Therefore the clinical implications of the differential expression of the mucin genes need further investigation.

Human cytomegalovirus immediate-early protein IE2 tethers a transcriptional repression domain to p53

The IE2 gene of human cytomegalovirus has been implicated in the development of coronary restenosis, and the gene product appears to inhibit p53-dependent transactivation. Here we describe an analysis of the IE2-p53 interaction. Repression of p53 function by IE2 requires two separable domains of IE2. The N terminus of IE2 interacts with p53. IE2 has little effect on the ability of p53 to bind specific DNA sequences. Reduction of the transactivation activity of p53 is caused by a transcriptional repression function contributed by the C-terminal domain of IE2. These findings suggest that IE2 may function as a transcriptional repressor, which is recruited to p53's target genes by interacting with p53.

Helicobacter Pylori Infection in Patients with Gastric Adenocarcinoma

We examined the biologic tumor behavior in Helicobacter pylori-seropositive patients with gastric adenocarcinoma. A total of 214 consecutive patients with pathologically confirmed adenocarcinoma of the stomach who underwent gastric resection were studied. The stored serum samples were tested for serum antibody to H. pylori by using a highly sensitive and specific IgG enzyme-linked immunosorbent assay. The difference in H. pylori-seropositive and seronegative patients with gastric adenocarcinoma was evaluated in terms of various clinicopathologic parameters. A multivariate logistic regression analysis was used to adjust for potential confounding variables. Antibodies to H. pylori were detected in 65.9% of patients with gastric adenocarcinoma. H. pylori-seropositive patients were younger than seronegative patients and had infiltrative tumor according to Ming's criteria. When adjusted for age, infiltrative tumor come out stronger. These findings suggest that H. pylori infection may be related to infiltrative type gastric adenocarcinoma; further study is necessary.

Paclitaxel-induced apoptosis in human gastric carcinoma cell lines

BACKGROUND

Gastric cancer is one of the most common cancers in Asia. Chemotherapy and radiation therapy have had limited success. Recently, paclitaxel has been found to be effective against a variety of cancers, including lung, breast, ovary, melanoma, and prostate. Whether paclitaxel is effective in the treatment of gastric cancer is not known and is worthy of investigation.

METHODS

Human gastric carcinoma cell lines NUGC-3 and SC-M1 were examined for response to paclitaxel treatment. Cancer cells were treated with paclitaxel (0.001, 0.01, 0.1, and 1 microM) for 1-3 days. Cell number was counted by hemocytometer and cell viability was determined by the trypan blue exclusion method. Cell cycle progression and expression of proliferating cell nuclear antigen (PCNA) were examined by flow cytometry. The percentage of apoptotic cells was determined after staining with hematoxylin and eosin.

RESULTS

Paclitaxel was cytotoxic to the two human gastric carcinoma cell lines examined. The growth-inhibiting dose was 0.01 microM. Paclitaxel-treated gastric carcinoma cells were arrested mainly in G2/M phases before apoptosis. However, treatment with 0.01 microM of paclitaxel resulted in a decrease of cells at G0/G1 phases without an increase of cells at G2/M phase indicating that paclitaxel was also cytotoxic to gastric carcinoma cells at G0/G1 phases. In addition, the expression of PCNA was significantly increased in 0.1 and 1 microM paclitaxel-treated cells, suggesting that DNA repair was increased in these cells.

CONCLUSIONS

Paclitaxel is effective in growth inhibition of gastric carcinoma cell lines in clinically attainable concentrations. Our results suggest that paclitaxel is a potential chemotherapeutic drug for gastric carcinoma.

Tissue potassium, selenium, and iron levels associated with gastric cancer progression

The contents of 10 minor and trace elements in histologically confirmed gastric adenocarcinomas and their corresponding normal gastric mucosal tissues obtained from 39 patients at the time of gastric resection were simultaneously determined by instrumental neutron activation analysis. Specimens were irradiated by reactor neutrons and subsequently subject to direct analysis using a high-resolution HPGe gamma-spectrometer. Univariate analysis revealed that gastric cancer tissues had significantly higher concentrations of Fe, K, Mg, Na, Rb, Se, and Zn than normal gastric mucosal tissues. However, multivariate analysis found that Fe, K, and Se were independent elements that associated with gastric cancer. Upon further evaluation of their clinical significance, we found a high tissue K level was related to lymphatic duct metastasis. High Se tissue levels were linked to intestinal type adenocarcinoma. A positive correlation was found between high Fe levels and vascular involvement. These findings suggest that Fe and K are associated with gastric cancer progression. Se is involved in carcinogenesis of stomach in high-risk areas. The mechanisms that underlie the corresponding pathohistological features deserve further study.

Molecular epidemiology of cytomegalovirus infection in kindergarten children

This study was conducted to determine the source of cytomegalovirus (CMV) excretion in children who had persistent viruria. A total of 287 children, ages 3-5 years, enrolled in two kindergartens were followed for 9 months, and 28.8% of 139 CMV-infected children were found to have shed virus persistently in urine for > or = 3 months. A polymerase chain reaction (PCR)-based method provided direct evidence to demonstrate differences in CMV strains shed by 32 persistent shedders selected at random. The glycoprotein B (gB) nucleotide regions of CMV were amplified and analyzed by restriction enzyme digestion. The CMV strains shed by most of these children showed different restriction profiles compared with strains from their playmates. It is considered that persistent reactivation of endogenous CMV is the most plausible explanation.

A movable and regulable inactivation function within the central region of a temperature-sensitive p53 mutant

p53 is the most frequently mutated gene in human cancer. Naturally occurring mutations of p53 are mainly located within a region containing residues 100-300 and are predominantly of missense type, resulting in loss of the protein's DNA binding activity. Here we show that this type of mutation also represses the p53 N-terminal activation domain. The repression activity is localized in the central region of mutant p53 containing residues 101-318. Interestingly, the central region of a temperature-sensitive mutant p53N247I possesses a movable and regulable inactivation function. It represses other activities present on the same polypeptide chain without strict regard to the configuration of that polypeptide only at the nonpermissive temperature (37 degrees C) and not at the permissive temperature (30 degrees C). Furthermore, this mutant p53 region exhibits no other activity, and its function is independent of endogenous p53 status.

Complete genomic RNA sequences of cucumber mosaic virus strain NT9 from Taiwan

The nucleotide sequences of the RNAs 1, 2, and 3 of the cucumber mosaic virus (CMV) Taiwan isolate NT9 were determined and compared at both the nucleotide and amino acid levels with those of CMV strains Fny, Y, O from subgroup I and strain Q from subgroup II. NT9-CMV has an unique feature at the C-terminus of the 3a protein which contains four extra-amino acids. All three RNAs and their encoded proteins, except 2b, of NT9-CMV share more than 90% identity with those of strains in subgroup I, and 72%-85% identity with Q-CMV. The results indicated the conservation of sequences of CMV derived from different geographical locations.

Morbidity and mortality after radical gastrectomy for patients with carcinoma of the stomach

BACKGROUND

This study sought to analyze the morbidity and mortality rates after radical gastrectomy for carcinoma, since the operation has been criticized as too morbid for the benefits it may provide.

STUDY DESIGN

A prospective study of 474 patients who underwent radical gastrectomy was conducted.

RESULTS

The overall morbidity and mortality rates were 20.1 and 3.0 percent, respectively. The morbidity and mortality rates fell significantly from 27.0 to 15.7 percent (p = 0.003) and 5.5 to 1.1 percent (p < 0.001), respectively, after the first 200 cases. By logistic regression analysis, it was found that male gender, combined organ(s) resection, extended lymphadenectomy, respiratory system disease, and tumor location were significantly related to postoperative morbidity. In regard to the extent of lymphadenectomy, relative to R2 resection (n = 102), the odds ratio for morbidity after R3 resection (n = 217) was 2.13, and for R4 resection (n = 155) it was 3.12. Age older than 65 years, total gastrectomy, combined organ(s) resection, and respiratory system disease were factors that negatively affected operative mortality.

CONCLUSIONS

These observations suggested that radical gastrectomy can be performed with an acceptable risk of morbidity and mortality in a general hospital.

Effect of ethanol on the protein secondary structure of the human gastric mucosa, in vitro

The effect of ethanol on the secondary conformational structure of proteins of the human gastric mucosa was investigated by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) spectroscopy. The IR peak intensity and position of each structural component of gastric mucosa was found to change significantly with the ethanol concentration and length of exposure. The peak intensity due to the beta-sheet and/or beta-turn conformational structure in amide I and II bands of gastric mucosa clearly increased after treatment with ethanol. Moreover, the peak at 1635 cm-1 shifted to 1630 cm-1 after treatment with 40% ethanol for 3 h, or 80% ethanol for 1 h, and a distinct shoulder also appeared at 1643 cm-1. This shift occurred more rapidly and was more pronounced after exposure of mucosa to 80% ethanol, compared with the effect of 40% ethanol, but the alpha-helical structure at the amide I and II bands was not influenced by either concentration of ethanol. Ethanol treatment might also transform the secondary structure of amide III in gastric mucosa from an alpha-helix to a mainly random coil with extensive unfolding. The absorption between 1180 and 980 cm-1, which is assigned to glycoprotein structure, was also reduced after treatment with ethanol. This strongly indicates that ethanol influences the conformation of the lipids and proteins of human gastric mucosa, leading to their deformation.

Cloning and characterization of the endogenous retroviral-tRNA(Glu) multigene family from human genomes of different racial backgrounds

An 8.3-kb human endogenous retroviral-tRNA(Glu) (HERV-E)-encoding cDNA clone and a 1.5-kb genomic clone were isolated from a Chinese-derived cervical cancer cell line, CC7T, and their sequences determined. The former is a full-length endogenous retroviral cDNA containing corresponding u5-gag-pol-env-u3-r regions. The latter is a partial retroviral DNA segment, covering the gag and pol genes. Analysis of normal human DNA by Southern blot hybridization with three specific HERV-E molecular DNA probes revealed complex restriction-fragment length polymorphisms (RFLP), implying that the human genome contains diverse proviral structures and dispersed integration sites. The complex patterns were virtually identical between DNAs from African-Americans, Asians and Caucasians, with only a few minor variations. The data suggest that these proviral sequences were mostly incorporated into the human genome before racial divergence and, hence, may serve as markers for distinct chromosomal sites.

Differential expression of the human metastasis adhesion molecule CD44V in normal and carcinomatous stomach mucosa of Chinese subjects

BACKGROUND

CD44 is a cell surface adhesion molecule involved in cell-cell and cell-matrix interactions. Tumor cells transfected to overexpress the isoform CD44V readily gain access to lymph nodes and form distant metastases.

METHODS

Monoclonal antibodies directed at epitopes common to known CD44 isoforms were used to investigate CD44V expression in 30 normal gastric mucosa tissues, 64 different gastric adenocarcinomas, 20 metastatic adenocarcinoma lymph nodes and 4 established gastric carcinoma cell lines. In addition, CD44V gene expression in six gastric adenocarcinoma tissues and four gastric cancer cell lines were investigated by northern blotting.

RESULTS

Immunohistochemistry screening of 30 subjects with normal gastric mucosa did not reveal expression of CD44 variants. Areas of intestinal metaplasia, a precancerous lesion, were stained with antibodies against either V5- or V6-containing isoforms of CD44. Tubular and signet-ring cell types of adenocarcinoma were strongly positive for epitopes encoded by CD44 variants containing exons V5 (41/49 and 10/10, respectively). Some tubular type adenocarcinomas (15/49) also expressed CD44 variants containing the V6 epitope. Tumor differentiation was closely related to CD44 V5 expression (P < 0.001). In addition, 18 of 20 gastric adenocarcinomas metastatic to lymph nodes expressed the V5 epitope of CD44 and 4 of 20 expressed the V6 epitope. Analysis of four established gastric adenocarcinoma cell lines revealed that two had moderate to strong expression of exons V5 and V6 of CD44. An antibody directed against CD44 variants containing exons V8 to V10 strongly stained all gastric adenocarcinoma cell lines. Northern blotting demonstrated that all four tumor cell lines and six gastric carcinoma mucosa tissues expressed CD44V.

CONCLUSIONS

Generation of CD44 splice variants may be closely linked with gastric carcinoma tumorigenesis and differentiation. In addition, expression of CD44 variants containing exons V5 and V6 may be used as an indicator of evolving gastric cancer.

Differential expression of the human metastasis adhesion molecule CD44V in normal and carcinomatous stomach mucosa of Chinese subjects

BACKGROUND

CD44 is a cell surface adhesion molecule involved in cell-cell and cell-matrix interactions. Tumor cells transfected to overexpress the isoform CD44V readily gain access to lymph nodes and form distant metastases.

METHODS

Monoclonal antibodies directed at epitopes common to known CD44 isoforms were used to investigate CD44V expression in 30 normal gastric mucosa tissues, 64 different gastric adenocarcinomas, 20 metastatic adenocarcinoma lymph nodes and 4 established gastric carcinoma cell lines. In addition, CD44V gene expression in six gastric adenocarcinoma tissues and four gastric cancer cell lines were investigated by northern blotting.

RESULTS

Immunohistochemistry screening of 30 subjects with normal gastric mucosa did not reveal expression of CD44 variants. Areas of intestinal metaplasia, a precancerous lesion, were stained with antibodies against either V5- or V6-containing isoforms of CD44. Tubular and signet-ring cell types of adenocarcinoma were strongly positive for epitopes encoded by CD44 variants containing exons V5 (41/49 and 10/10, respectively). Some tubular type adenocarcinomas (15/49) also expressed CD44 variants containing the V6 epitope. Tumor differentiation was closely related to CD44 V5 expression (P < 0.001). In addition, 18 of 20 gastric adenocarcinomas metastatic to lymph nodes expressed the V5 epitope of CD44 and 4 of 20 expressed the V6 epitope. Analysis of four established gastric adenocarcinoma cell lines revealed that two had moderate to strong expression of exons V5 and V6 of CD44. An antibody directed against CD44 variants containing exons V8 to V10 strongly stained all gastric adenocarcinoma cell lines. Northern blotting demonstrated that all four tumor cell lines and six gastric carcinoma mucosa tissues expressed CD44V.

CONCLUSIONS

Generation of CD44 splice variants may be closely linked with gastric carcinoma tumorigenesis and differentiation. In addition, expression of CD44 variants containing exons V5 and V6 may be used as an indicator of evolving gastric cancer.