Colorectal carcinoma and its precursors: role of argyrophilic nucleolar organizer regions (AgNORs).

A silver colloid technique to identify Argyrophilic Organizer Region (AgNOR) was applied to 5 hyperplastic polyps, 5 adenomas with low grade dysplasia, 5 adenomas with high grade dysplasia and 15 adenocarcinomas of the large bowel (5 well differentiated, 5 moderately differentiated and 5 poorly differentiated). The authors suggest the plainness and usefulness of simultaneous application of clumps per cell, AgNORs per clump and total AgNORs counts in the evaluation of neoplastic and preneoplastic lesions of the colon. In fact the results show that the number of clumps per cell is useful to distinguish hyperplastic polyps from adenomas with high grade dysplasia and from all the adenocarcinomas. Using the number of AgNORs per clump there is significant difference between hyperplastic polyps and adenomas with high grade dysplasia and between adenomas with low grade dysplasia and well differentiated adenocarcinomas. Finally the total number of AgNORs can discriminate hyperplastic polyps from adenomas with high grade dysplasia and these from adenomas with low grade dysplasia.     

Tissue microarray-determined expression profiles of cyclooxygenase-2 in colorectal adenocarcinoma: association with clinicopathological parameters

Accumulated evidence reveals that increased cyclooxygenase-2 (COX-2) is involved in the development of colorectal cancer. Our purpose was to quantitate COX-2 expression in colorectal cancers using tissue microarray analysis and look for an association with clinicopathological stage. Immunohistochemical analysis of COX-2 was performed in tissue microarray slides containing 90 specimens including 32 well-differentiated, 35 moderately differentiated, and 23 poorly differentiated colorectal adenocarcinomas. All colorectal adenocarcinomas showed significant immunohistochemical expression of COX-2 when compared to normal colon epithelia. However, there was no significant difference in immunostaining scores between poorly, moderately, and well-differentiated tumors (195 +/- 28, 214 +/- 26 and 200 +/- 24, respectively). The COX-2 immunostaining score correlated significantly with T stage (P < 0.05) but not with N or M stage. The positive expression rates of CK20 were 97% for well-differentiated, 94% for moderately differentiated, and 65% for poorly differentiated colorectal adenocarcinomas, suggesting that CK20 may not be an effective discriminator between poorly differentiated colorectal adenocarcinoma and metastatic adenocarcinoma.     

Association of cortactin and fascin-1 expression in gastric adenocarcinoma: correlation with clinicopathological parameters.

Cortactin and fascin-1 are important factors in tumor progression. We tested the hypothesis that cortactin and fascin-1 expression correlates with clinicopathological parameters of gastric adenocarcinoma. Immunohistochemical analysis of cortactin and fascin-1 was done using tissue microarrays of 100 surgical specimens, including 20 well-differentiated, 20 moderately differentiated, and 60 poorly differentiated gastric adenocarcinomas. Among the 20 well-differentiated gastric adenocarcinomas, 15 cases (75%) showed negative or weak staining (1+); 5 cases (25%) had moderate (2+) or strong (3+) cortactin expression. Among the 60 poorly differentiated gastric adenocarcinomas, more than three-quarters of the cases (76.7%) had moderate or strong cortactin expression; 14 cases (23.3%) had weak staining. Of 20 well-differentiated gastric adenocarcinoma cases, 14 (70%) showed negative or weak staining of fascin-1, whereas nearly one-third (30%) had moderate or strong expression. Among the 60 poorly differentiated gastric adenocarcinomas, 32 (53.3%) exhibited moderate or strong fascin-1 expression; fewer than half of the cases showed negative or weak staining. Higher intensity of cortactin and fascin-1 staining correlated directly with more-advanced cancer stages (TNM) and inversely with survival rates. Our findings suggest the possibility that pharmacological inhibitors of cortactin and fascin-1 activity may slow down tumor progression and prolong survival time in patients with gastric adenocarcinomas.     

Decreased matriptase/HAI-1 ratio in advanced colorectal adenocarcinoma of Chinese patients

Matriptase is a serine protease expressed by tumors of surface epithelial origin. We tested the expressions of matriptase and hepatocyte growth factor activator inhibitor-1 (HAI-1) maybe associated with the progression of colorectal adenocarcinoma. Immunohistochemical analysis of matriptase and HAI-1 was performed in tissue microarray slides of 91 colorectal adenocarcinomas with various degrees. The matriptase scores in moderately (346.7 +/- 10.6) and poorly differentiated (248.1 +/- 12.9) were significantly lower than those in well differentiated (368.4 +/- 9.6) colorectal adenocarcinomas. The matriptase/HAI-1 ratios in poorly (1.8 +/- 0.4) and moderately differentiated (1.8 +/- 0.3) were significantly lower than in well differentiated (2.2 +/- 0.2) colorectal adenocarcinomas. Otherwise, the matriptase scores and matriptase/HAI-1 ratio showed significant reverse correlation with more advanced TNM stages of colorectal adenocarcinomas in Chinese patients. In conclusion, pharmacological inhibitors of matriptase may not be effective treatment for advanced colorectal adenocarcinomas.     

Computer-assisted grading of adenocarcinoma in prostatic aspirates

Conventional cytologic grading of fine needle aspirates of prostatic adenocarcinoma has been shown neither to be reproducible nor to correlate well with histologic grading. This study developed a tumor grade classification based on computerized cytomorphometric features and compared the results to conventional grading of companion tissue sections. The image analysis system evaluated architectural features of the aspirates (mainly cell cluster features and interrelationships) as well as nuclear features. Thirty-five prostatic adenocarcinomas (8 well, 19 moderately and 8 poorly differentiated) were evaluated. Discriminant functions based on data collected at medium and high resolution distinguished between aspirates from low-grade (well-differentiated) and high-grade (poorly differentiated) adenocarcinomas with 81% accuracy. Moderately differentiated cancers could not be classified as a distinct group. This study suggests that accurate grading of prostatic adenocarcinoma in fine needle aspirate smears requires the evaluation of medium-resolution features related to specimen cellularity and uniformity or crowding of cell clusters as well as of high-resolution features of nuclear area, perimeter and coarseness of chromatin texture. These findings are compared to those of other schemes for the cytologic grading of prostatic aspirates.     

胃癌细胞DNA含量、AgNOR计数与其生物学特性关系的研究

本文使用图像分析技术测定了正常胃粘膜、萎缩性胃炎、不典型增生及胃癌共８９例细胞ＤＮＡ相对含量及ＤＮＡ倍体分布;并用银染方法对８９例细胞核仁形成区嗜银蛋白进行定量分析。结果显示：不典型增生往往可观察到与胃癌相似的ＤＮＡ核型即高异倍体的出现,高异倍体的出现可能是重要的癌前标志;在胃粘膜病变中,ＡｇＮＯＲ值随病变异型程度的加重而递增,各组间差异均有非常显著性意义（Ｐ＜０．０１）。早期癌、浸润癌和转移癌间,以及癌转移过程中粘膜层、肌层、淋巴结内癌细胞ＤＮＡ含量无明显差异;ＡｇＮＯＲｓ计数均值差异亦无非常显著性意义（Ｐ＞０．０５）。随癌细胞分化程度升高,ＤＮＡ含量增多及异倍体出现率升高;各期胃癌除粘激腺癌与分化型腺癌差异无显著性意义外,余各型胃癌ＡｇＮＯＲｓ值随分化程度升高而增多,差异有显著性意义（Ｐ＜０．０５或Ｐ＜０．０１）。因此,ＤＮＡ含量及倍体分析,ＡｇＮＯＲｓ计数与胃癌的生物学行为密切相关,可作为胃癌早期诊断,癌前病变预测以及组织分级的一种重要指标。     

Modified basement membrane composition during bronchopulmonary tumor progression.

During tumor progression, the extracellular matrix (ECM) and particularly the basement membrane (BM) appear to be dynamic structures that are not only degraded but also deposited around tumor clusters. In this study we examined by immunohistochemistry the localization of three chains of Type IV collagen (alpha1, alpha3 and alpha5), Type VII collagen, and laminin 5 at different stages of bronchopulmonary cancers. In normal tissues, alpha1(IV) chain was detected in all BMs (bronchial, vascular, alveolar, and glandular), alpha5(IV) chain was present only in vascular BM, and laminin 5 and Type VII collagen were co-localized in bronchial and glandular BMs, whereas alpha3(IV) immunolabeling was totally absent from normal bronchi. In well-differentiated carcinomas, alpha3(IV) chain staining was found in some neosynthetized BMs interfacing the tumor cell and the stromal compartment, contrasting with the total absence of labeling in normal tissues. alpha1(IV) chain showed strong reactivity in all BM. Laminin 5 and Type VII collagen were also detected in neosynthetized BM. In poorly differentiated invasive cancers, alpha3(IV) chain and Type VII collagen were not found, whereas laminin 5 and alpha1(IV) chain persisted. The most important modifications in BM composition during tumor progression therefore appear to be the appearance of the alpha3 (IV) chain in well-differentiated carcinomas and its subsequent disappearance in poorly differentiated carcinomas, together with the loss of type VII collagen. alpha5(IV) chain distribution was restricted in vascular BM of well- and poorly differentiated carcinomas. These results show that the composition of BM is modified during the progression of bronchopulmonary tumor, emphasizing that the BM represents a dynamic element in tumor progression and has an important role in tumor cell invasiveness.     

The potential usefulness of monoclonal antibodies in the determination of histologic types of lung cancer in cytologic preparations

Two monoclonal antibodies (MAbs) were tested for their reactivity with antigens of exfoliated malignant cells in respiratory secretions of lung cancer patients. MAb CE 407 was developed from tissue culture cell line SW 756, derived from human uterine cervical squamous cell carcinoma; MAb BL 99-57 was developed from cell line T-24, derived from human transitional cell bladder cancer. MAb CE 407 reacted preferentially with squamous cell carcinomas (80%) and with some (44%) of the adenocarcinomas of the lung; BL 99-57 reacted with 76% of the adenocarcinomas, but only with 27% of the squamous cell carcinomas of the lung. The reactivity of BL 99-57 was more apparent in well-differentiated adenocarcinomas (89% positive), but less in poorly differentiated adenocarcinomas (65% positive). Neither of these antibodies reacted with antigens of small cell anaplastic carcinoma. These two MAbs may be useful in differentiating histologic types of lung cancer in cases that are difficult to diagnose morphologically and/or in which tissue is not available for study.     

Differential expression of antioxidant enzymes in various hepatocellular carcinoma cell lines

Recent evidence suggests that reactive oxygen species (ROS) play an important role in the pathogenesis of various illnesses, and the ROS and antioxidant enzymes are highly associated with cell differentiation and diseases. In this study, we tested the hypothesis that specific antioxidant enzymes are differentially expressed in hepatocellular carcinoma (HCC) cell lines with various degrees of differentiation. We compared the expression of several antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GRx), and glutathione peroxidase (GPx) in five HCC cell lines with well (Hep G2 and Hep 3B) or poor (HA22T/VGH, HA55T/VGH, and SK-Hep-1) differentiation. Our results showed that both well-differentiated HCC cell lines expressed extremely higher CAT and GRx enzyme activities than all three poorly differentiated ones. Moreover, the protein and mRNA levels of CAT were much higher in two well-differentiated HCC cell lines than in all three poorly differentiated ones. Both well-differentiated HCC cell lines also showed a higher protein or mRNA expression of Cu/ZnSOD and MnSOD than three poorly differentiated ones. Our results demonstrate that specific antioxidant enzymes (especially, CAT and GRx) are differentially expressed in HCC cell lines with well or poor differentiation. These findings suggest that CAT and GRx are two potential differentiation markers for HCC.     

The presence of elafin, SLPI, IL1-RA and STNFalpha RI in head and neck squamous cell carcinomas and their relation to the degree of tumour differentiation

Biopsy samples of head and neck carcinomas were investigated with regard to elafin, secretory leukocyte protease inhibitor (SLPI), interleukin 1-receptor antagonist [(IL)1-RA] and soluble tumour necrosis factor alpha receptor antagonist (STNFalpha RI). SLPI and elafin are serine protease inhibitors produced in the serous cells of the upper respiratory airways and in the keratinocytes, respectively. We have now found the presence of elafin and SLPI in squamous cell carcinomas of the upper respiratory tract (tonsillar, hypopharyngeal, tongue, mouth floor, gingival and laryngeal cancer). Significantly higher amounts of SLPI and elafin are present in well-differentiated and moderately differentiated tumours than in poorly differentiated tumours (p < 0.0001 and p < 0.0015). Tumour necrosis factor-alpha and IL-1beta have been shown to stimulate the production of SLPI and elafin. Since these cytokines can both be difficult to detect, we chose to study their inhibitors, STNFalpha RI and IL1-RA, instead. IL1-RA was expressed in highly differentiated tumours as well as in poorly differentiated ones. No significant difference was seen between the groups. STNFalpha RI was only found in very small amounts, sparsely distributed in the tumours, and was not related to the degree of differentiation.     

The differentiation of hepatocyte-like cells from monkey embryonic stem cells

Embryonic stem cells (ESC) hold great potential for the treatment of liver diseases. Here, we report the differentiation of rhesus macaque ESC along a hepatocyte lineage. The undifferentiated monkey ESC line, ORMES-6, was cultured in an optimal culture condition in an effort to differentiate them into hepatocyte-like cells in vitro. The functional efficacy of the differentiated hepatic cells was evaluated using RT-PCR for the expression of hepatocyte specific genes, and Western blot analysis and immunocytochemistry for hepatic proteins such as alpha-fetoprotein (AFP), albumin and alpha1-antitrypsin (alpha1-AT). Functional assays were performed using the periodic acid schiff (PAS) reaction and ELISA. The final yield of ESC-derived hepatocyte-like cells was measured by flow cytometry for cells that were transduced with a liver-specific lentivirus vector containing the alpha1-AT promoter driving the expression of green fluorescence protein (GFP). The treatment of monkey ESC with an optimal culture condition yielded hepatocyte-like cells that expressed albumin, alpha1-AT, AFP, hepatocyte nuclear factor 3beta, glucose-6-phophatase, and cytochrome P450 genes and proteins as determined by RT-PCR and Western blot analysis. Immunofluorescent staining showed the cells positive for albumin, AFP, and alpha1-AT. PAS staining demonstrated that the differentiated cells showed hepatocyte functional activity. Albumin could be detected in the medium after 20 days of differentiation. Flow cytometry data showed that 6.5 +/- 1.0% of the total differentiated cells were positive for GFP. These results suggest that by using a specific, empirically determined, culture condition, we were able to direct monkey ESC toward a hepatocyte lineage.     

Morphometric analysis of AgNORs in thin-layer, liquid-based liver specimens

OBJECTIVE: To detect argyrophilic nucleolar organizer regions (AgNORs) in ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) liver fine needle aspiration (FNA) specimens and to define the diagnostic value of their quantitative analysis in the evaluation of hepatic lesions. STUDY DESIGN: ThinPrep liquid-based FNA biopsy specimens from 49 malignant and benign liver lesions were resampled, fixed in 95% ethanol and stained with the AgNOR technique in accordance with the 1-step colloid method. The specimens included 11 benign and 38 malignant lesions (23 poorly differentiated hepatocellular carcinomas [HCCs] and 15 poorly differentiated metastatic adenocarcinomas [MCs]). Morphometric analysis was performed using a Zeiss Axiolab microscope (Carl Zeiss GmbH, Jena, Germany) with a mechanical stage fitted with a Sony-iris CCD videocamera (Tokyo, Japan). The videocamera was connected to a Pentium III P/C (Intel Corp., Santa Clara, California, U.S.A.) loaded with the appropriate image analysis software. The measurements were performed with ImageScan software (Jandel Scientific, Erkrath, Germany). The number of AgNORs per nucleus (NN) and the total area per nucleus occupied by AgNORs (AR) were calculated semiautomatically. Statistical analysis was performed using the SPSS software package (Chicago, Illinois, U.S.A.). RESULTS: The least significant deviance test for multiple comparisons revealed that NN differed significantly between the 3 groups of samples examined (P < .0001). The mean NN values in HCCs and MCs were significantly different (P < .0001). Logistic regression model demonstrated that as NN increased, the probability of a MC diagnosis decreased (<4%). AR values were different at a statistically significant level only between benign and malignant specimens (P = .00006), not between HCCs and MCs (P = .933). CONCLUSION: Quantitative analysis of AgNORs in ThinPrep specimens could be a diagnostically useful method in liver disease.     

Chemopreventive efficacy of 25-hydroxyvitamin D3 in colon cancer

Recently, it has been reported that 25-hydroxyvitamin D3-1alpha-hydroxylase [1alpha(OH)ase, CYP27B1], required to convert non-toxic 25-hyxdroxyvitamin D3 [25(OH)D(3)] to its active metabolite [1alpha,25(OH)(2)D(3)], is present in the epithelial cells of the human colon. In the present study, the potential chemoprotective role of 25(OH)D(3) was evaluated for colon cancer using the HT-29, human colon cancer cell line. Colon cancer cells were treated with 25(OH)D(3) (500nM or 1muM), 1alpha,25(OH)(2)D(3) (500nM), cholecalciferol (D3, 1muM) or vehicle and cell number determined at days 2 and 5 post-treatment. Results showed that both 25(OH)D(3) and 1alpha,25(OH)(2)D(3) induced dose- and time-dependent anti-proliferative effects on the HT-29 cells, with maximum inhibition noted at day 5. Western blot analyses revealed an up-regulation of VDR and 1alpha(OH)ase expression following 24h of treatment with 25(OH)D(3), and 1alpha,25(OH)(2)D(3). These results are consistent with the expression of VDR and 1alpha(OH)ase in samples of normal colonic tissue, aberrant crypt foci (ACFs) and colon adenocarcinomas. The VDR expression was sequentially increased from normal to pre-cancerous lesions to well-differentiated tumors and then decreased in poorly differentiated tumors. Expression of 1alpha(OH)ase was equally expressed in normal, pre-cancerous lesions and malignant human colon tissues. The increased expression of 1alpha(OH)ase in colon cancer cells treated with the pro-hormone and its anti-proliferative effects, suggest that 25(OH)D(3) may offer possible therapeutic and chemopreventive option in colon cancer.     

Evidence for c-myc in the signaling pathway for TGF-beta in well-differentiated human colon carcinoma cells

Previously, we described a model culture system for comparing responsiveness of poorly differentiated and well-differentiated human colon carcinoma cells to exogenous growth factors. While polypeptide growth stimulators elicited an up-regulation of c-myc, as well as a mitogenic response in the well-differentiated cells, the poorly differentiated cells were insensitive to exogenous growth stimulators. We now show, by thymidine incorporation experiments and autoradiographic analysis, that transforming growth factor beta 1 (TGF-beta) abrogated the mitogenic responses to the growth factors epidermal growth factor + insulin + transferrin (IC50 = 0.8 ng/ml), as well as to nutrients (basal medium; IC50 = 0.2 ng/ml) in the well-differentiated cells. The poorly differentiated cells did not respond to TGF-beta. Moreover, TGF-beta (10 ng/ml) completely abrogated the growth factor-stimulated up-regulation of c-myc in the TGF-beta responsive, well-differentiated colon carcinoma cells. Addition of TGF-beta to the TGF-beta-responsive, well-differentiated cells, at a time after c-myc had been transiently up-regulated in response to growth stimulatory factors, resulted in a loss of responsiveness to TGF-beta. Addition of TGF-beta to these cells at increasing time periods after EIT stimulation also resulted in a loss of the TGF-beta-induced repression of c-myc. The results suggest an important role for c-myc in the mechanism of action of TGF-beta in well-differentiated human colon carcinoma cells.     

Expression of transforming growth factor alpha (TGF alpha) in differentiated rat mammary tumors: estrogen induction of TGF alpha production

Primary well-differentiated dimethylbenzene alpha-anthracene (DMBA)-or nitrosomethylurea (NMU)-induced rat mammary adenocarcinomas that are estrogen dependent possess biologically active and immunoreactive transforming growth factor alpha (TGF alpha), which can be detected in a sort agar growth-promoting assay and by a specific liquid-phase competitive RIA, respectively. In contrast, tissue extracts prepared from transplantable undifferentiated DMBA-I and NMU-II rat mammary carcinomas that are estrogen independent and metastatic exhibit low or undetectable levels of TGF alpha. In addition, the primary DMBA- and NMU-induced rat mammary adenocarcinomas express a specific 4.8-kilobase TGF alpha mRNA species, whereas little or no TGF alpha mRNA can be detected in the transplantable DMBA-I and NMU-II tumors. Primary tumors synthesize type IV basement membrane collagen, whereas the transplantable tumors elaborate very little type IV collagen. Either TGF alpha or estrogens can differentially enhance the synthesis of type IV collagen by 0.5- to 4-fold over total protein synthesis in primary cultures of normal mouse mammary epithelial cells or in primary NMU-induced tumor cells, respectively. Therefore, TGF alpha could function as an estrogen-inducible autocrine growth factor for well differentiated rat mammary tumor cells by its ability to selectively regulate type IV collagen synthesis. Estrogens can modulate TGF alpha production in vivo in primary DMBA-induced rat mammary tumors, because ovariectomy results in a rapid decline (within 6 h) of TGF alpha mRNA levels. This response to estrogens can also be observed in vitro. Primary DMBA- or NMU-induced rat mammary tumor cells cultured in the presence of 17 beta-estradiol (10(-8) M) for 4 days show an increase in the level of TGF alpha mRNA over cells not treated with estrogen. This increase in TGF alpha mRNA is paralleled by a 2- to 3-fold increase in the levels of immunoreactive TGF alpha that can be detected and in the conditioned medium from estrogen-treated cells. These results suggest that TGF alpha may be an adjunct marker for those mammary tumors that are well differentiated adenocarcinomas and estrogen dependent and that estrogen-independent tumors do not constitutively produce TGF alpha or express TGF alpha mRNA.     

Evaluation of DNA and nuclear protein features for their use in describing normal and malignant endometrium

Different feature sets (geometric, densitometric, and textural) derived from DNA and nuclear protein staining were evaluated for their use in describing atrophic, secretory, and proliferative endometrium, and well-differentiated stage I and moderately differentiated stage I adenocarcinomas of the endometrium. It was found that the pattern of significant differences among these groups varied between feature sets, while remaining consistent within a set of features. The DNA density and run-length features were not very effective in describing group mean differences, whereas the co-occurrence features revealed significant differences among most groups. The protein run-length features were the only ones that consistently showed a difference between proliferative endometrium and well-differentiated adenocarcinomas. Analyses repeated on only cells in the G0/G1 DNA region improved the differentiation between moderately differentiated adenocarcinomas and the other groups. It was concluded that the use of DNA and nuclear protein texture features are effective in describing group differences that cannot be described by DNA content only.     

Variation of HLA-ABC surface antigen expression on adenocarcinoma of the colon in correlation with the degree of differentiation

The expression of HLA class I antigens was tested on biopsy specimens originating from 90 patients suffering from adenocarcinoma of the colon. Three different samples were examined from each specimen: one from the tumor and the other two from the neighboring surrounding surgical margins. Twenty-seven out of 27 well-differentiated carcinomas were found highly positive for the presence of HLA class I antigens. Most of the moderately well differentiated tumors (37 out of 46) were weakly positive. None of the poorly differentiated tumors (n = 11) nor the mucin-producing tumors (n = 6) expressed HLA class I antigens. In 180 histologically normal colonic epithelia from patients suffering from adenocarcinoma of the colon (surgical edges free from tumorous tissue of the same specimens) no positive expressions were found. These results tend to suggest that class I HLA-ABC deficient, poorly differentiated tumors may possibly evade lethal immune aggression by HLA-restricted cytotoxic T cells and thus progress to overt malignancy. This negative expression may provide an explanation for the poorer prognosis observed among patients afflicted by a poorly differentiated adenocarcinoma or mucin-producing adenocarcinoma of the colon. Furthermore, these results tend to suggest that enhanced expression of HLA class I antigens on colonic epithelium could serve as a clinical laboratory indication for further examination looking for the possible emergence of neoplasm. If further verified, this may prove to serve as a predictive diagnostic tool for screening populations at risk.     

Immunohistochemical demonstration of the carbonic anhydrase isoenzymes I and II in pancreatic tumours

Summary The location of carbonic anhydrase (CA) isoenzymes I, II and VI in normal and neoplastic pancreatic tissue was studied using polyclonal antisera and the immunoperoxidase technique. Samples were obtained from patients with well-differentiated (n = 4), moderately differentiated (n = 1) and poorly differentiated (n = 4) ductal adenocarcinomas, cystadenocarcinoma (n = 2), adenosquamous carcinoma (n = 1), acinar adenocarcinoma (n = 1), gastrinoma (n = 3), insulinoma (n = 3) and glucagonoma (n = 1). The control specimens were from a patient with traumatic laceration of the pancreas. The normal and malignant endocrine tissue showed intense positive staining for CA I localized in the cells expressing glucagon. In the exocrine pancreatic tissue, CA II was detected in the normal and neoplastic ductal epithelium. No specific staining was detected with anti-CA VI serum in either normal or malignant tissue.     

Effect of alpha-1-antichymotrypsin on activity of DNA primase isolated from human stomach adenocarcinoma cells

This paper describes an investigation into the effect of alpha-1-antichymotrypsin (ACT) on DNA primase. DNA primase was partially purified from human stomach carcinoma cells. It was found that poly(dC)-dependent DNa primase activity was inhibited by ACT and the inhibition was proportional to the concentration of the inhibitor. The inhibitory effect of ACT remained even after ACT lost most of its chymotrypsin-inhibitory activity by heat treatment. Poly(dT)-dependent primase activity was enhanced by the presence of ACT. The enhancement was effective up to a concentration of 1mg/ml.