Abnormal pattern of cell proliferation in the entire colonic mucosa of patients with colon adenoma or cancer

Using autoradiography after 1 h of pulsed labeling with tritiated thymidine in endoscopic biopsy specimens from normal-appearing mucosa, cell proliferation was determined at six predetermined sites of the whole colon in patients with neoplastic disease of the large bowel and was compared with that of subjects without macroscopic colonic pathology. The labeling index (the percentage of cells incorporating [3H]thymidine) was 8.6 +/- 0.5 (mean +/- SEM) in 13 patients with colon carcinoma (p less than 0.001 vs. 16 control patients whose labeling index was 4.9 +/- 0.2) and 9.1 +/- 0.4 in 11 patients with a large adenoma in the colon (p less than 0.001 vs. controls). Twenty-one patients with one or more small adenomas (diameter less than 1 cm) had a moderately increased cell proliferation compared with controls (labeling index 6.2 +/- 0.3, p less than 0.02 vs. controls). In patients with neoplastic disease an enlargement of the proliferative compartment was found, whereas 6 patients with Crohn's colitis had values for labeling index and a distribution of labeled cells along the crypt comparable to that of control subjects. An increased cell proliferation was found along the entire colon under each of the neoplastic conditions studied. These findings indicate that although neoplastic lesions develop in a limited area of the colon, the entire large bowel may be at risk for tumor growth.     

Effects of gastric fundectomy and antrectomy on the colonic mucosa in the hamster.

The effects of gastric fundectomy and antrectomy on the colonic mucosa were studied in hamsters over 5 and 25 days. Sham-operated animals served as controls. Basal plasma gastrin concentrations were significantly increased after fundectomy and significantly decreased after antrectomy. Five days after fundectomy, there was a significant increase in scintigraphically determined colonic tissue [3H]-thymidine uptake and [3H]-thymidine labeling index of goblet cells, both of which were reduced 5 days after antrectomy. After fundectomy, the labeling index was maximal in differentiating-proliferative cells in the midportion of the colonic crypts, whereas the labeling index of the immature proliferative cells at the base of the crypts did not differ from that in the controls. On day 25, the crypt size and the number and percentage of goblet cells in the crypts were significantly increased in fundectomized animals. The number and percentage of goblet cells in antrectomized animals were significantly reduced on day 25. It is concluded that fundectomy in the hamster induces colonic mucosal hyperplasia with goblet cell proliferation, whereas antrectomy leads to retardation of colonic goblet cell proliferation.     

Variability of cell proliferation in the proximal and distal colon of normal rats and rats with dimethylhydrazine induced carcinogenesis

AIM：To investigate the patterns of cell proliferation in proximal and distal colons in normal rats and rats with1,2-dimethylhydrazine(DMH)induced carcinogenesis using the thymidine analogue bromodeoxyuridine.METHODS:Colonic crypt cell proliferation was immunohistochemically detected using the anti-bromodeoxyuridine Bu20a monoclonal antibody.RESULTS:Marked regional differences were found in both groups.Total labelling index(LI)and proliferative zone size in both normal(8.65±0.34vs7.2±0.45,27.74±1.07vs16.75±1.45)andDMH groups(13.13±0.46vs11.55±0.45,39.60±1.32vs35.52±1.58)were significantly higher in distal than in proximal colon(P<0.05).although the number of cells per proxmal crypt was greater(31.45±0.20vs34.45±0.39,42.68±0.53vs49.09±0.65,P<0.001).Crypt length,total LT and proliferative zone size all increased in both proximal and distal regions of DMH rats compared to normal controls(P<0.0001).In DMH-treated rat colon a shift of labelled cells to higher crypt cell positions was demonstrated distally whist a bi-directional shift was evident proximally(P<0.05).CONCLUSION:Our results show that changes in cell proliferation patterns,as assessed by bromodeoxyuridine uptake,can act as a reliable intermediate marker of colonic cancer formation.Observed differences between proliferation patterns in distal and proximal colon may be associated with the higher incidence of tumors in t he distal colon.     

Immunohistochemical study of epithelial cell proliferation in hyperplastic polyps, adenomas, and adenocarcinomas of the large bowel

A monoclonal antibody to bromodeoxyuridine was used in tissue specimens previously incubated with bromodeoxyuridine to show S-phase cells by immunohistochemical technique. Biopsy specimens of normal mucosa (n = 10), hyperplastic polyps (n = 10), adenomas with low-grade dysplasia (n = 20), adenomas with high-grade dysplasia (n = 10), and invasive adenocarcinomas (n = 10) of the large bowel were studied. Labeling index and cell proliferative patterns were analyzed. No statistically significant difference was found in labeling index between normal mucosa and hyperplastic polyps or between adenomas with high-grade dysplasia and adenocarcinomas. The labeling index was significantly lower in normal mucosa and in hyperplastic polyps than in adenomas and adenocarcinomas (p less than 0.001). The difference in labeling index between adenomas with high-grade dysplasia and low-grade dysplasia was also statistically significant (0.01 less than p less than 0.05). In normal mucosa and in hyperplastic polyps the proliferative zone was confined to the lower two-thirds of the crypt; no kinetic activity was found in the upper portions of the crypt or in surface epithelium. In adenomas the labeled cells were either present in the upper third or scattered along the whole axis of the crypt and in the surface epithelium. Labeling patterns in invasive carcinomas were similar to those observed in adenomas with high-grade dysplasia. The difference in proliferative patterns between hyperplastic polyps and adenomas supports a different significance of the two polypoid lesions in the histogenesis of large bowel cancer; our results confirm the subsequent steps of the adenoma-carcinoma sequence. Immunohistochemical labeling patterns observed with monoclonal antibody to bromodeoxyuridine in polypoid and cancer lesions of the large bowel are similar to those described by autoradiographic studies.     

Restoration of colorectal continuity reverses atrophy in human rectal mucosa

Cell kinetic activity and adaptive response of rectal mucosa from patients with Hartmann's procedure were studied before and after restoration of colorectal continuity. Patients without colostomy and with normal rectal mucosa were used as controls. Autoradiography ofin vitro labeled mucosal samples with [³H]thymidine was used. The proliferative activity in the rectal crypts was estimated by measuring labeling and mitotic indices, total DNA of isolated crypts, and total crypt cell numbers. One hundred forty days after creating a proximal end colostomy, labeling index (P<0.05), mitotic index (P<0.01), DNA content per crypt (P<0.05), and number of cells per crypt (P<0.05) decreased significantly compared to control values. Restoration of colorectal continuity resulted in a significant increase of the labeling index (P<0.05), the mitotic index (P<0.07), the DNA content per crypt (P<0.05), and the cell number per crypt (P<0.05). There were no significant differences between the postclosure values and the controls. These data indicated that excluding the human rectal mucosa from fecal stream determined a mucosal atrophy that could be reversed by restoration of colorectal continuity.     

Proliferating cell nuclear antigen in oesophageal diseases; correlation with transforming growth factor alpha expression.

This study was designed to correlate mucosal proliferation in Barrett's oesophagus with expression of a growth promoting peptide, transforming growth factor alpha (TGF alpha). Oesophageal mucosa was studied from 50 patients with oesophageal disease who had been treated by oesophagectomy. Histological analysis showed a range of oesophageal pathology - 18 patients had gastric type Barrett's mucosa, 18 had intestinal type Barrett's mucosa, and 14 had oesophageal adenocarcinomas. Sections were stained immunohistochemically for proliferating cell nuclear antigen (PCNA) (an index of cellular proliferation) and TGF alpha. PCNA immunostaining was seen mainly in the basal cells of the neck/foveolar epithelial compartment of the glands in Barrett's oesophagus. However, in mucosa with high grade dysplasia, the proliferative compartment extended upwards into the superficial layers of the glands. At least 2000 cells were counted in each patient to determine the proportion with PCNA immunoreactivity (PCNA labelling index). The labelling index was highest in adenocarcinoma (25%) and in Barrett's intestinal type mucosa with high grade dysplasia (26%) compared with intestinal type mucosa with no significant dysplasia (20%) and Barrett's gastric type mucosa (12%). There was a significant positive correlation between PCNA labelling indices and TGF alpha expression in Barrett's mucosa (p less than 0.01). In glands showing high grade dysplasia, TGF alpha immunoreactivity was seen in the same regions of the glands as PCNA immunoreactivity, indicating the possibility of involvement of TGF alpha in (pre) neoplastic proliferation in Barrett's oesophagus.     

Colonic mucosal proliferation after pancreaticobiliary diversion in the hamster

The effect of pancreatioobiliary diversion (PBD) on the colonic mucosa was studied in hamsters over 5, 10, and 24 days. Sham-operated animals served as controls. At all three time intervals, experimental animals had increased plasma cholecystokinin concentrations and decreased gastrin concentrations. Five days after PBD, there was an increase in scintigraphically measured [³H]thymidine incorporation into colonic tissue. Correspondingly, there was an increase in the [³H]thymidine DNA labeling index of goblet cells in the colonic mucosa. The total number of cells in the colonic crypt columns were significantly increased on days 5, 10 and 24. Whether this proliferative response in the colon is due to increased release of cholecystokinin, enterolucagon, other aberrations of hormones or growth factors, or simply an increased bile load on the colonic mucosa remains to be clarified. Such further studies may reveal an alternative animal model for studies on risk factors in colonic carcinogenesis.This study was supported by grants from the Swedish National Cancer Association, Cancerfunds of Östergötland County, and the Society of Medicine in Linköping, Sweden.     

Proliferative compartment deregulation in the non-neoplastic colonic epithelium of familial adenomatous polyposis.

Previous work has shown abnormalities in the proliferative activity of the colorectal mucosa in familial adenomatous polyposis (FAP). Some doubts remain about the validity of these findings because of difficulties in excluding adenomatous crypts, particularly in methods using tritiated thymidine, bromodeoxyuridine, and ornithine decarboxylase. The proliferative activity of the epithelium in colonic resections from 20 FAP patients was compared with that of age, sex, and site matched controls using a new monoclonal antibody MIB1 to assay the expression of Ki-67 antigen in routinely processed tissue. The labelling indices were very similar in the polyposis and control cases (25.5 (1.4)% and 26.7 (1.7)% respectively) but analysis of the distribution of labelled cells showed a significant shift of the proliferative compartment towards the luminal surface in the FAP group. Specifically, the labelling index was lower in the basal fifth of the polyposis crypts and higher in the two fifths at the luminal surface. These results show that analysis of proliferative activity in FAP is now achievable in routine histological material and indicate deregulation of proliferative control in the FAP colonic crypt. This may form a useful diagnostic adjunct to standard clinical and molecular genetic techniques, particularly in view of the current interest in dietary and pharmacological intervention in sporadic colorectal carcinoma.     

Epithelial cell proliferation during colonic chemical carcinogenesis in the rat

To define the significance of alterations in epithelial cell proliferation as a marker of high risk mucosa for colorectal cancer, we examined cell proliferative events in the colonic mucosa during chemical carcinogenesis using in vitro bromodeoxyuridine labelling and by analysing serial colonoscopic biopsy specimens from dimethylhydrazine (DMH)-treated rats. In both the rectum and flexure of the colon, an increased labelling index of colonic epithelial cells, an upward extension of the proliferating zone and an upward shift of the major area of DNA synthesis of epithelial cells were observed during DMH-induced colonic carcinogenesis in rats. These changes preceded the development of the colonic tumour and were observed in endoscopically normal rectal mucosa where the tumour was absent. We confirmed the altered cell proliferative events preceding the development of the tumour by examining serial colonoscopic biopsies. The results suggest that these alterations are features that identify premalignant colonic mucosa in DMH-treated rats.     

Colonic crypt cell proliferation state assessed by whole crypt microdissection in sporadic neoplasia and familial adenomatous polyposis

BACKGROUND: It has yet to be established whether proliferative activity in the macroscopically normal colonic mucosa is causally correlated with neoplastic risk. Measurement of proliferative activity in human subjects is of necessity usually undertaken using indirect methods with inherent limitations, and relatively little has been published on the effect of normal biological variables on such indices. AIMS: To establish the validity of mitosis counts following whole crypt microdissection as an index of the crypt cell proliferative state (CCPS) and to examine the effect of normal biological variables (age, sex, and colonic site) and colonic neoplasia on the mitotic index in macroscopically normal human colon. SUBJECTS: Mucosal samples were obtained at colectomy or colonoscopy from 107 individuals (24 controls, 23 sporadic adenoma patients, 31 sporadic carcinoma patients, and 29 patients with familial adenomatous polyposis (FAP)). METHODS: Mucosal specimens were hydrated, hydrolysed, and small groups of crypts separated from the main specimen under a dissecting microscope. The total number of mitoses/crypt were counted by one observer for each of 10 complete crypts. RESULTS: Validation work established that whole crypt mitoses counts were reliable and reproducible. There was no relation between age and mean mitoses/crypt (Pearson correlation coefficient -0.1). The CCPS count was higher for males than for females (difference in means 2.8 (95% confidence interval 0.80-4.66)) among controls but there was no gender difference in the three disease groups. For all disease groups and controls, the crypt mitotic count showed a significant linear increase (p=0.004) from the rectum to the caecum. Biopsies from within 5 cm of the macroscopic margin of a carcinoma (near) gave a mean mitosis count of 12.6 while those from more than 10 cm (far) were lower but not significantly so (p=0.12) with a count of 9.0. The mean mitoses/crypt were similar for the controls and adenomas (5.6 and 4.7, respectively) but greater for the cancers and especially for FAP (8.3 and 14.2, respectively). Statistical analysis confirmed that there were significant differences (p<0.05) between controls and all disease groups together, between sporadic disease and FAP, and between adenoma and carcinoma subjects at each of the four colonic sites. Post hoc comparison by t test showed significantly greater CCPS for FAP compared with controls (p<0.001) and for sporadic cancer versus controls (p=0.04). CONCLUSIONS: Whole crypt microdissection and mitosis counting is a reliable, reproducible, and robust technique for assessing CCPS in the human colon. CCPS is unaffected by age but increases from the distal to the proximal colon. CCPS is increased if a sporadic cancer is present and markedly increased in FAP. However, the precise relation of an increased CCPS to the neoplastic process remains uncertain.     

Variability of cell proliferation in the proximal and distal colon of normal rats and rats with dimethylhydrazine induced carcinogenesis

AIM: To investigate the patterns of cell proliferation inproximal and distal colons in normal rats and rats with 1,2-dimethylhydrazine (DMH) induced carcinogenesis using thethymidine analogue bromodeoxyuridine.METHODS: Colonic crypt cell proliferation wasimmunohistochemically detected using the anti-bromodeoxyuridine Bu20a monoclonal antibody.RESULTS: Marked regional differences were found in bothgroups. Total labelling index (LI) and proliferative zone sizein both normal (8.65±0.34 vs 7.2±0.45, 27.74±1.07 vs16.75±1.45) and DMH groups (13.13±0.46 vs 11.55±0.45,39.60±1.32 vs35.52±1.58) were significantly higher in distalthan in proximal colon (P＜0.05), although the number ofcells per proximal crypt was greater (31.45±0.20 vs34.45±0.39, 42.68±0.53 vs49.09±0.65, P＜0.0001). Crypt length,total LI and proliferative zone size all increased in both proximaland distal regions of DMH rats compared to normal controls(P＜0.0001). In DMH-treated rat colon a shift of labelled cellsto higher crypt cell positions was demonstrated distally whilsta bi-directional shift was evident proximally (P＜0.05).CONCLUSION: Our results show that changes in cellproliferation patterns, as assessed by bromodeoxyuridineuptake, can act as a reliable intermediate marker of coloniccancer formation. Observed differences between proliferationpatterns in distal and proximal colon may be associated withthe higher incidence of tumors in the distal colon.     

Cellular proliferation in proximal and distal rat colon during 1,2-dimethylhydrazine-induced carcinogenesis

Sequential changes in proliferative parameters in proximal and distal colonic crypts were studied during 1,2-dimethylhydrazine-induced carcinogenesis using [3H]thymidine autoradiography as a probe. 1,2-dimethylhydrazine (20 mg/kg) and vehicle (ethylenediaminetetraacetic acid) control rats received weekly s.c. injections for 20 wk. All animals received a pulse of [3H]thymidine before death at weeks 2, 6, 10, 16, 22, 26, or 30. In addition, 8 animals unexposed to 1,2-dimethylhydrazine or vehicle served as baseline controls. Dramatic regional differences were noted in the baseline controls. Crypt length, labeling index, and proliferative zone size were all significantly greater distally than proximally (p less than 0.05), whereas the labeling index of the proliferative zone tended to be enhanced proximally. During 1,2-dimethylhydrazine treatment the crypt length, labeling index, and proliferative zone size increased in both regions. As these parameters changed in parallel, the differences between proximal and distal colon did not change significantly during carcinogenesis. Actual tumor formation did differ, however, with tumors appearing earlier and in greater abundance in the distal colon. These findings show similar proliferative changes in both the proximal and distal colon during 1,2-dimethylhydrazine treatment and indicate that the enhanced baseline proliferative state of the distal colon compared with the proximal colon must be considered in the process of tumor formation.     

Serum bile acids, programmed cell death and cell proliferation in the mucosa of patients with colorectal adenomas

BACKGROUND: Deoxycholic acid induced programmed cell death and an imbalance with cell proliferation may favour colorectal tumourigenesis according to 'in vitro' studies, but information is lacking on the relationships occurring 'in vivo' in humans. AIMS: To evaluate whether serum deoxycholic acid is associated with programmed cell death and cell proliferation in colonic mucosa. METHODS: In 10 patients with colorectal adenomas, we measured fasting serum levels of bile acids; and, in normal colonic mucosa, programmed cell death by the TUNEL technique and cell proliferation by immunohistochemical staining with anti-Ki67. Total and compartmental indices for both activities were calculated. RESULTS: Among serum bile acids, only total deoxycholic acid (median: 0.89 micromol/L +/- 0.54 95% CI), showed a significant positive correlation with the total and basal compartments PCD Index (r = 0.68, p < 0.05). Total proliferation index showed no correlation with either total PCD Index, or bile acids. Within the median compartment of the crypt, cell proliferation was negatively associated with all unconjugated bile acids. CONCLUSIONS: The positive association between deoxycholic acid and programmed cell death in the basal compartment of the crypt, and the negative association of cell proliferation and unconjugated bile acids in the median compartment, do not seem to support the co-carcinogenic effect of deoxycholic acid.     

Acid fibroblast growth factor reduces rat intestinal mucosal damage caused by ischemia-reperfusion insult

AIM: To detect the effects of acid fibroblast growth factor (aFGF) on apoptosis and proliferation of intestinal epithelial cells in differentiation or proliferation status to explore the protective mechanisms of aFGF. METHODS: Wistar rats were randomly divided into sham-operated control group (C, n= 6), intestinal ischemia group (I,n = 6), aFGF treatment group (A, n= 48) and intestinal ischemia-reperfusion group (R,n= 48). Apoptosis of intestinal mucosal cells was determined with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) technique. Proliferating cell nuclear antigen (PCNA) protein expression and distribution were detected with immunohistochemical method. Plasma levels of D-lactate were determined with modified Brandts method. RESULTS: In A group, administration of exogenous aFGF could improve intestinal histological structure and decrease plasma D-lactate levels at 2-12 h after the reperfusion compared with R group. The apoptotic rates and PCNA protein expressions were not increased until 2 h after reperfusion and were maximal at 12 h. After reperfusion for 2-12 h, the apoptotic rates were gradually augmented along the length of jejunal crypt-villus units. Administration of aFGF could significantly reduce the apoptotic response at 2-12 h after reperfusion (P<0.05). Apoptosis rates in villus and crypt epithelial cells in A group at 12 h after reperfusion were (62.5±5.5)% and (73.2±18.6)% of those in R group, respectively. Treatment of aFGF could apparently induce protein expression of PCNA in intestinal mucosal cells of A group compared with R group during 2-12 h after reperfusion (P<0.05). There were approximately 1.3- and 1.5-times increments of PCNA expression levels in villus and crypt cells in A group at 12 h after reperfusion compared with R group, respectively. CONCLUSION: Intestinal I/R insult could lead to histological structure change and apoptotic rate increment. The protective effects of aFGF against ischemia/reperfusion in rat intestinal mucosa might be partially due to its ability to inhibit ischemia/reperfusion-induced apoptosis and to promote cell proliferation of crypt cells and villus epithelial cells.     

Prebiotic treatment in experimental colitis reduces the risk of colitic cancer

Background and Aim: Germinated barley foodstuff (GBF) is a prebiotic product that reduces colonic mucosal inflammation and the clinical symptoms observed in ulcerative colitis (UC). The risk of contracting colorectal cancer is higher in patients with UC than in that of the general population. The aim of this study is to apply this prebiotic approach to control chronic colitis and to reduce the incidence of colitic cancer. Methods: Repeated and intermitted dextran sulfate sodium administration to male Sprague–Dawley rats was used for the chronic and subacute colitis models. GBF was added as the diet (10% w/v). The incidence of adenomatous high‐grade dysplasia, and pathophysiological observations, including the proliferative cell nuclear antigen (PCNA) labeling index, and clinical score, cecal organic acid profile, and the accompanying β‐glucosidase activity were determined. Results: In the chronic phase, the incidence of adenomatous dysplasia was only confirmed in the control group, and the GBF group had no dysplasia in the entire colon; the stratified squamous epithelium area of GBF was significantly lower than that of the controls. GBF treatment significantly lowered the cecal succinate content and significantly increased β‐glucosidase activity compared to the controls. In addition, colonic mucosal inflammatory damage was comparable between the two groups, while the PCNA labeling index of the colonic mucosa in the GBF group was significantly lower than that of the control group. However, in the subacute phase, the mucosal damage score of GBF was significantly attenuated, and the PCNA labeling index of the colonic mucosa in the GBF group was significantly higher than that of the control group. Conclusion: This preliminary study demonstrated that GBF effectively prevents colitis‐related dysplasia and inflammatory change in chronic and subacute colitis models by modulating the intestinal environment as a prebiotic. This prebiotic might contribute to the prevention of mucosal damage, to show different proliferative effects on the epithelium in the regeneration and steady states.     

Epithelial cell proliferation in the rectal stump of patients with ileorectal anastomosis for ulcerative colitis

Epithelial cell proliferation in the rectal stump after ileorectal anastomosis for ulcerative colitis was studied in 19 patients. This was achieved through in vitro incorporation of tritiated thymidine in mucosal biopsies and radioautographic analysis of the number and position of labelled nuclei in the crypts. Rectal biopsies from nine unoperated patients with ulcerative colitis and from 10 controls, were processed simultaneously. Except for one, all patients were clinically in remission. The crypt length and number of labelled cells per crypt column were found to be similar in the rectal mucosa from the three groups of subjects. The mean labelling index, although low 8.9%, was higher (p less than 0.05) in operated patients compared with controls; but the dispersion of individual values was similar in both groups. There was an extension of the proliferative compartment towards the surface in 88% of unoperated patients and in 60% of operated patients. In addition, there was a shift of the major zone of proliferation from the lower to the middle third of the crypt in 17% of operated patients and from the lower to the upper third of the crypt in 14% of unoperated patients. No correlation was found between the labelling index and either the age of patient, the duration of disease or the period elapsed after ileorectal anastomosis. Interestingly, among operated patients with a colitis for over 10 years, 42% had a quite normal proliferative pattern with a corresponding mean postoperative period of 7.5 years.     

Epithelial proliferation in Barrett's esophagus by proliferating cell nuclear antigen immunolocalization.

Proliferating cell nuclear antigen (PCNA) is an auxiliary protein to DNA polymerase delta and is an absolute requirement for cellular proliferation. Specialized-type Barrett's columnar-lined esophagus (CLE) is associated with adenocarcinomatous change. In the present study, the cellular proliferation of three histological types of CLE was assessed by semiquantitative evaluation of PCNA immunolocalization in 93 biopsy specimens from 45 patients using the murine monoclonal PC10. Statistical comparison was performed by the Mann-Whitney U test. Luminal surface cell labeling was uncommon in all histological types other than specialized CLE where 25 of the 43 biopsy specimens had at least occasional luminal surface cell labeling. Mean crypt labeling score of 4.06 for specialized type exceeded that for junctional (mean, 3.12; P < 0.001) and fundic types (mean, 1.6; P < 0.001). Gland cell PCNA staining scores for specialized-type CLE (mean, 3.18) exceeded that of junctional (mean, 1.97; P < 0.001) and fundic (mean, 1.04; P < 0.001). Summated PCNA scores for specialized-type, mean of 8.29, exceeded junctional mean score of 5.45 (P < 0.001) and fundic mean score of 2.76 (P < 0.001). PCNA immunolocalization reveals a high proportion of cells in cycle in the specialized-type CLE and expansion of the proliferative compartment, which may explain the association of specialized-type CLE with malignancy.     

Hepatoblastoma: DNA nuclear content,proliferative indices,and pathology

Abstract: Hepatoblastoma (HB) is the most frequent malignant liver tumor in infancy, and both its biological features and its prognostic behavior are still under investigation. DNA content and proliferative activity of the tumor have been considered as biological parameters related to the tumor's aggressiveness. The present study attempts to investigate the possible association between histologic subtype, DNA content, and proliferative indices in HB. DNA content and the proportion of cells in the S-phase were assessed by flow cytometry in 34 cases of HB (14 prior to chemotherapy, 20 after chemotherapy), using formalin-fixed, paraffin-embedded archival samples. The proliferative cell nuclear antigen (PCNA) labeling index was also evaluated by immunohistochemistry, and both the flow cytometry (FC) and the immunohistochemical data were correlated with tumor pathology. A significant association was found between histological type, DNA content and the percentage of cells in the S-phase, with aneuploidy and the highest proportions of S-phase cells significantly associated with embryonal tumors. The PCNA labeling index was found to be significantly higher in embryonal than in fetal phenotype. The biological heterogeneity of HB is confirmed by the different nuclear content of the fetal (diploid) and embryonal (aneuploid) epithelial components of the tumor, also ruling out the likelihood of fetal (diploid) clones deriving from the embryonal (aneuploid) neoplastic cells. Since the highly proliferative neoplastic clones (i.e., embryonal) are thought to be more sensitive to antimitotic drugs, further studies are indicated to determine the relationship between ploidy, proliferative indices and chemoresponsiveness.     

内皮素-1在良性前列腺增生症前列腺组织中的表达及其意义

用免疫组化的方法研究25例良性前列腺增生症和7例正常前列腺组织中内皮素-1及bcl-2增殖细胞核抗原(PCNA)表达，结果内皮素-1在增生前列腺与正常前列腺之间的表达存在显著性的差异，内皮素-1的表达与PCNA表达之间存在相关性，内皮素-1的表达与bcl-2的表达之间无相关性。认为内皮素-1通过其生物学特性参与了前列腺增生症的病理生理过程。     

Intravenous nucleosides and a nucleotide promote healing of small bowel ulcers in experimental enterocolitis

Our aim was to evaluate the possible beneficial effect of intravenous nucleosides and a nucleotide in healing small bowel ulceration in a rat model of enterocolitis. Fourteen Lewis female rats were randomized into total parenteral nutrition (TPN,N=7) and TPN + nucleosides and a nucleotide (NS/NT,N=7) groups. After adaptation, two doses of indomethacin (7.5 mg/kg) were administered subcutaneously 24 hr apart to each animal in both groups. Concomitant with the first dose of indomethacin, TPN or TPN + NS/NT·were infused for four days. The TPN and TPN + NS/NT were isocaloric and isonitrogenous. At the end of four days, total ulcer length in the entire small bowel was measured. The mucosa surrounding ulcers was studied by optical microscopy. Immunohistochemistry was performed for proliferating cell nuclear antigen (PCNA). Ileal crypt and villus lengths were measured with an eyepiece micrometer, crypt-villus ratios were calculated, and crypt mitotic index and percentage of PCNA-labeled cells determined to assess cellular proliferation. Total ulcer length decreased significantly in the TPN + NS/NT group compared to the TPN group (42 vs 76 mm). In the TPN + NS/NT versus TPN group, the ileal mucosa surrounding ulcers showed significantly greater crypt length (21%) and there was increased crypt-villus ratio (0.53 vs 0.39), crypt mitotic index (1.2 vs 0.9), and PCNA labeling (43% vs 30%). We conclude that in rats with indomethacin-induced enterocolitis, administration of TPN + NS/NT for four days resulted in significant healing of small bowel ulcers, as indicated by decreased ulcer length. This effect of NS/NT appears to relate, in part, to increased cell proliferation, evidenced by increased crypt length, crypt-villus ratio, mitotic index, and PCNA labeling.