Cell kinetics and biochemical parameters in breast cancer

The study analyzes biochemical and cell kinetic parameters to characterize solid tumor growth in humans. The concentrations of polyamines, CEA, the thymidine labeling index (T.L.I.) and the mitotic index (M.I.) were determined on fragments of neoplastic tissue from 18 patients with breast carcinoma. Urinary polyamines were evaluated in the same patients.

Two groups of patients were distinguished according to the median value of the T.L.I. In the group with high T.L.I., M.I. and tissue polyamines were significantly higher than in the group with low T.L.I., whereas tissue CEA was lower, though in a not statistically significant way. Urinary polyamines showed no variations between groups.

These preliminary results showed that T.L.I. levels were higher in patients who relapsed during a 4-year follow-up than in patients achieving complete remission and remaining disease free. Results concerning polyamine concentration showed that the tissue polyamine level in breast carcinoma indicated proliferative activity, but this does not seem to be valuable for current prognostic purposes

Relationship between Cytosol Tps, Tpa and Cell Proliferation

The serological tumor marker tissue polypeptide antigen (TPA) and the more recently identified tissue-specific polypeptide antigen (TPS) have been reported to be indicators of the proliferation rate of the tumor. In the present investigation we compared the cytosol level of the two markers with the proliferative activity of the tumor measured using the 3H-thymidine labelling index. The preliminary results presented here show that higher TLI is associated with lower cytosol levels of both TPA and TPS. TPA and TPS in the cytosol were significantly associated. These findings are in agreement with the previously demonstrated association between high TPA cytosol levels and better prognosis in breast cancer. Further studies are ongoing in order to:

1. confirm these findings in a larger patient series;

2. investigate any possible prognostic indication provided by TPS;

3. evaluate any possible biological meaning of the negative association between TPA/ TPS and TLI in the cytosol of breast cancer.

In vivo effects of rosiglitazone in a human neuroblastoma xenograft

BACKGROUND

Neuroblastoma (NB) is the most common extra-cranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. There is in vitro evidence that the peroxisome proliferator-activated receptor gamma (PPARgamma) might be a target for pharmacological intervention in NB. We have previously demonstrated that the PPARgamma agonist rosiglitazone (RGZ) exerts strong anti-tumoural effects in the human NB cell line, SK-N-AS. The aim of this study was to evaluate whether RGZ maintains its anti-tumoural effects against SK-N-AS NB cells in vivo.

METHODS AND RESULTS

For this purpose, tumour cells were subcutaneously implanted in nude mice, and RGZ (150 mg kg(-1)) was administered by gavage daily for 4 weeks. At the end of treatment, a significant tumour weight inhibition (70%) was observed in RGZ-treated mice compared with control mice. The inhibition of tumour growth was supported by a strong anti-angiogenic activity, as assessed by CD-31 immunostaining in tumour samples. The number of apoptotic cells, as determined by cleaved caspase-3 immunostaining, seemed lower in RGZ-treated animals at the end of the treatment period than in control mice, likely because of the large tumour size observed in the latter group.

CONCLUSIONS

To our knowledge, this is the first demonstration that RGZ effectively inhibits tumour growth in a human NB xenograft and our results suggest that PPARgamma agonists may have a role in anti-tumoural strategies against NB.

3H-thymidine labelling index (TLI) as a marker of tumour growth heterogeneity: evaluation in human solid carcinomas

Many studies deal with the analysis of cell kinetic, cytogenetic, biochemical and molecular cell biology parameters to identify prognostic factors relating to tumour growth but all methods use only a small part of the total tumour mass. This study is devoted to the analysis of the heterogeneity of the growth of human solid tumours assaying proliferative activity by means of 3H-thymidine labelling index (TLI) in a fixed number of samples collected in different areas of the lesion (larynx and colon cancers), or in different lesions of the same subject (breast and bladder cancers). Each sample (at the macroscopic level) was divided into small fragments (at the microscopic level) and proliferative activity was determined. The analysis of variance for hierarchical designs demonstrated that in all cases a high component of the variance is attributable to the subjects and to the fragments whereas the variance attributable to the different areas is very low. The heterogeneity of proliferative activity displays a higher focal variability among the fragments (microscopic level) compared with that among areas (macroscopic level) within subjects, provided an adequate number of fragments and cells are counted. In multiple synchronous carcinoma of the bladder the wide variability of proliferation among the single lesions demonstrated that it is necessary to analyse all the tumours in a subject because each one is characterized by a different cell growth potential.

HERG potassium channels are constitutively expressed in primary human acute myeloid leukemias and regulate cell proliferation of normal and leukemic hemopoietic progenitors

An important target in the understanding of the pathogenesis of acute myeloid leukemias (AML) relies on deciphering the molecular features of normal and leukemic hemopoietic progenitors. In particular, the analysis of the mechanisms involved in the regulation of cell proliferation is decisive for the establishment of new targeted therapies. To gain further insight into this topic we report herein a novel approach by analyzing the role of HERG K(+) channels in the regulation of hemopoietic cell proliferation. These channels, encoded by the human ether-a-gò-gò-related gene (herg), belong to a family of K(+) channels, whose role in oncogenesis has been recently demonstrated. We report here that herg is switched off in normal peripheral blood mononuclear cells (PBMNC) as well as in circulating CD34(+) cells, however, it is rapidly turned on in the latter upon induction of the mitotic cycle. Moreover, hergappears to be constitutively activated in leukemic cell lines as well as in the majority of circulating blasts from primary AML. Evidence is also provided that HERG channel activity regulates cell proliferation in stimulated CD34(+) as well as in blast cells from AML patients. These results open new perspectives on the pathogenetic role of HERG K(+) channels in leukemias.

Proposal for biochemical dosimeter for prolonged space flights

Radiation dosimetry has been developed by means of physical, chemical and biological methods. A different approach to calculate the absorbed dose is related to the assay in body fluids of some molecules that modify their concentration after irradiation. The salivary glands in humans appear particularly radiosensitive and the effects of ionizing radiation can be evaluated by means of the determination of serum amylase (produced by acinar cells) and Tissue Polypeptide Antigen (TPA, synthesized by ductal cells). Patients submitted to external radiotherapy for tumours localized in the head and neck region show early and late effects on salivary glands. The modification of amylase activity and TPA appear as a progressive statistically significant increase within two days. Levels of 200-300% of baseline value are reached, followed by a rapid return to preirradiation levels. The use of different doses per fraction and fractionation schedules (conventional or multiple daily fractionations) confirm the direct correlation between the absorbed dose and serum amylase and TPA levels. It is worth noting that the irradiation of pancreas region did not produce any effect on amylase activity. The correlation may be assumed as linear for a short dose range (2-6 Gy) whereas in the range from 0.5 to 10 Gy a sigmoid curve represents the experimental data. Both molecules confirm their capability to quantify the absorbed dose in patients with thyroid carcinoma submitted to metabolic treatment with iodine-131. The effects of radiation are species-specific and are absent in laboratory mammals. The easiness of the determination of serum amylase and TPA lead us to propose the test as biochemical dosimeter for cosmic rays exposure during prolonged staying in the space.

Polyamines as biochemical indicators of radiation injury

The search for parameters of different nature to quantify radiation damage is carrying on from many years in humans and lab animals. The polyamines (spermidine and spermine) are ubiquitous polycations with many metabolic functions and can be easily assayed by HPLC method. Their involvement in cell proliferation has been evidenced in healthy and tumour tissues. Statistically significant reductions have been demonstrated in tissues and in red blood cells (RBC), in animals and in patients treated by total body irradiation (TBI) before bone marrow transplantation (BMT). In rats submitted to TBI with 3 Gy of gamma radiations, tissue polyamines significantly decrease during the early phase of injury in tissues with high proliferative activity (small intestine, spleen) whereas do not show any modification in kidney. When recovery takes place, the polyamines significantly increase and return to control levels when a normal morphology is restored. In patients submitted to radiation therapy, polyamines have been determined in urine and in RBC of patients with carcinoma of uterine cervix, head and neck and prostate, treated by external radiotherapy, and with thyroid cancer treated with iodine-131 therapy. The most interesting results has been obtained with RBC: in patients treated on the pelvis for prostate cancer a significant reduction during radiotherapy occurs, followed by the maintenance of low levels in patients with favourable outcome. It should be noted that polyamine levels before treatment appeared significantly higher than in healthy controls. After TBI the RBC polyamines show a dramatic fall to extremely low levels during the phase of marrow aplasia. The values show an increase corresponding to the engraftment of transplanted cells and to the following marrow repopulation. These evidences make the RBC polyamines very interesting parameters to monitor the radiation effects on humans.

Expression of Id helix-loop-helix proteins in colorectal adenocarcinoma correlates with p53 expression and mitotic index

Id helix-loop-helix (HLH) proteins function as regulators of cell growth and differentiation and when overexpressed can induce malignant transformation. In a series of 34 cases of primary human colorectal adenocarcinoma, immunoreactivity for Id1, Id2, and Id3 was found to be significantly elevated in tumor compared with normal mucosa (P = 0.001 for Id1 and Id2; P = 0.002 for Id3). No elevation of Id expression was observed in 17 cases of adenoma. Expression of Id1 and to a lesser extent of Id2 was correlated with mitotic index (P = 0.005 for Id1; P = 0.042 for Id2) in human adenocarcinomas, and expression of all three Id proteins was correlated with p53 immunoreactivity (a marker of mutational 'inactivation' of p53 function; P = 0.002 for Id1; P = 0.006 for Id2; P = 0.016 for Id3). In normal intestinal mucosa of p53-null mice and in spontaneous tumors arising in Min+/- mice, expression of all three Id proteins was also found to be up-regulated. Antisense oligonucleotide blockade of Id protein expression inhibited the proliferation of human adenocarcinoma cells. Enforced, ectopic expression of the E47 basic HLH (bHLH) protein in human adenocarcinoma cell lines efficiently sequestered endogenous Id proteins as Id-bHLH heterodimers, as shown by coimmunoprecipitation and subcellular colocalization studies. This led to growth arrest of the cells. Enforced overexpression of a mutant E47 protein, deficient in transactivation and DNA binding function, also partially inhibited cell growth. Taken together, these data imply that deregulated expression of Id proteins in colorectal adenocarcinoma arises at least in part as a consequence of loss of p53 function and contributes to the uncontrolled proliferation of tumor cells in colorectal cancer.

Biological properties associated with the enhanced lung-colonizing potential in a B16 murine melanoma line grown in a medium conditioned by syngeneic Corynebacterium parvum-elicited macrophages

A previous study by our laboratory showed that the peritoneal murine Corynebacterium parnum-elicited macrophages released into their growth medium an activity which enhanced the ability of B16-F10 melanoma cells to form experimental metastases in the lung of syngeneic mice. In the present study, we used a clone of B16-F10 line (F10-M3 cells) to investigate whether the increase in lung-colonizing potential due to the pro-clonogenic activity released by C. parvum-elicited macrophages was associated with biological properties characteristic of a metastatic phenotype. We have found that the pulmonary retention, growth rate in lung parenchyma, invasiveness through Matrigel, adhesiveness to IL-1-activated endothelium and MHC class I expression were increased in F10-M3 cells stimulated by the macrophage pro-clonogenic activity. By using an in vitro experimental protocol, the enhancement of lung-colonizing potential in the stimulated melanoma cells turned out to be a transient phenomenon as was the increase of invasiveness through Matrigel and the higher expression of MHC class I antigens. In conclusion, the melanoma cells stimulated by the pro-clonogenic activity released by C. parvum-elicited macrophages showed changes in biological parameters which are relevant to metastatic diffusion. These changes appeared as a temporary phenomenon which sustains the view that the metastatic phenotype represents a transient biological character influenced by host factors.

Prognostic significance of biologic markers in node-negative breast cancer patients: a prospective study

It is generally thought that future advances in the treatment and cure of breast cancer patients will be made possible through a deeper understanding of tumor biology and an improved capability to define the prognosis of each single patient. This will lead to the formulation of new, more selective, and patient-tailored therapies. It is therefore important, when studying potential prognostic factors, to follow methodologic requirements and guidelines which involve the carrying out of prospective studies as confirmatory steps. Repeatedly or recently investigated prognostic markers (tumor size, menopausal status, ER, PgR, 3H thymidine labeling index, c-erbB-2 and p27 expression) were evaluated on a series of 286 prospectively recruited node negative breast cancer patients who underwent loco-regional treatment alone and were closely followed. The individual and relative prognostic contribution of each variable with respect to other factors, as well as their ability to identify node negative patients at risk, were assessed by univariate and multivariate analysis. At a five-year follow-up, only tumor size (p = 0.021) and TLI (p = 0.016) individually proved to be significant prognostic indicators of relapse-free survival. Conversely, p27 expression was not related to RFS and c-erbB-2 expression appeared to have only a short-term effect on patient prognosis. TLI and tumor size, tested in multivariate analysis along with ER and menopausal status, maintained their independent prognostic relevance. The study, performed on a large series of node-negative patients given loco-regional treatment alone, for the first time prospectively recruited, showed the prognostic relevance of TLI and its independence from other clinico-pathologic and biologic factors over a five-year period.

Bcl-w expression in colorectal adenocarcinoma

We have found that the anti-apoptotic Bcl-2 family protein, Bcl-w, was frequently expressed in colorectal adenocarcinomas, with 69/75 showing positive staining with anti-Bcl-w IgG. Adenomas demonstrated a much lower frequency of Bcl-w expression (only 1 of 17), as did adenocarcinomas from other epithelial tissues such as breast (0/8), stomach (1112) and cervix (0/12). Bcl-w status could be related to the histopathological classification of the tumours, with TNM stage III tumours showing significantly higher levels of expression than tumours of better prognostic grade (at P = 0.009). Those patients with node involvement also had tumours with significantly elevated levels of Bcl-w (at P = 0.02), compared to those which were node-negative. The results suggest that Bcl-w could play a general role in the progression from adenoma to adenocarcinoma in the colorectal epithelium. Currently, more data are being collected to allow us to assess the importance of Bcl-w for disease progression and patient survival.

Nitroxides and malignant human tissues: electron spin resonance in colorectal neoplastic and healthy tissues

Healthy and neoplastic colorectal human tissues of as many as 12 patients have been studied, immediately after surgery, by electron spin resonance (ESR) of stable nitroxides at physiological temperature. Cells were maintained in a living state using the McCoy's 5A culture medium. The very low concentration changes of hydrophilic and lipophilic nitroxides allowed us to establish that the response to the oxidative stress induced by the occurrence of nitroxides in healthy and tumor cells was very weak, thus suggesting these compounds are good candidates for contrast enhancement agents in magnetic resonance imaging of colorectal tumor. The analysis of the computed ESR line shape of lipophilic nitroxides in both healthy and malignant cells of the same patient agreed for an unmodified physical status of the membranes where they were mainly localized. The results reported here proved that the comparison between ESR results must be made in tissues from the same patient and that the physical status of the membranes depended more on the patient history than on changes in the colorectal cell membrane fluidity induced by the neoplastic process.

Correlation between DNA content and p53 deletion in colorectal cancer

OBJECTIVE

To find out whether tumour DNA content correlates with allelic loss of p53 and other pathological features in primary colorectal carcinomas.

DESIGN

Ongoing prospective study.

SETTING

University hospital, Italy.

SUBJECTS

128 patients who had undergone radical resections for colorectal carcinoma.

INTERVENTIONS

Flow cytometric measurement of tumour DNA content and detection of allelic loss on the short arm of chromosome 17 by Southern blot (restriction fragment length polymorphism) analysis in fresh tumour specimens.

MAIN OUTCOME MEASURES

Correlation between DNA ploidy and deletion of p53, as well as between these two genetic events and clinicopathological variables.

RESULTS

Interpretable DNA histograms were obtained for 122 tumour specimens. Forty-three tumours (35%) were diploid and 79 (65%) aneuploid. The diploid tumours were significantly more common in the proximal colon (from the caecum to the splenic flexure) than in the distal colon (from the descending colon to the rectum) (p = 0.002). The allelic state on the short arm of chromosome 17 was evaluated in 80 heterozygous patients. Forty-four tumour specimens (55%) showed deletion of 17p. Allelic loss of p53 was significantly more common in the distal and rectal tumours than in the proximal ones (p < 0.0001). Aneuploidy was more common among those tumours which had shown deletion of p53 than in those that had not (p = 0.0008).

CONCLUSIONS

DNA aneuploidy was significantly associated with the deletion of the p53 gene. This suggests that the functional loss of p53 may favour the growth and establishment of an aneuploid cell population within tumours. Tumours of the proximal and distal colon differ in their genetic nature.

Colonic cell proliferation in normal mucosa of patients with colon cancer

Cell kinetics parameters have been analysed in colonic mucosa at different distances from a tumour in patients with colon carcinoma. Total cell number (TCN), 3H thymidine labelling index (TLI), mitotic index (MI), Goblet cell index (GCI) and the distribution of labelled cells along the crypt column (cell position frequency plot) were determined in well-aligned crypts. Total cell number, GCI and the labelled cell position frequency plots were similar in different samples from the same individual. A negative linear correlation between TCN and TLI was observed. The analysis of the cell position plots showed two patterns 1) with a high concentration in the bottom fifth of the crypt and 2) with frequent labelled cells at high positions. Whereas a negative correlation between overall TLI and the percent contribution to the TLI of the lowermost fifth was seen, the correlation was positive for the next 3 fifths and labelling was absent in the last part of the crypt.

The effects of irradiation at different times of the day on rat intestinal goblet cells

Quantitative changes in jejunal goblet cells were studied in control and whole body irradiated rats using PAS-Alcian blue staining of crypt sections. A circadian dependence was observed when control animals were killed at different times during the light/dark cycle. Irradiation with 3 Gy produced a 2-3-fold increase within 36 h in goblet cells relative to controls, followed by a reduction to very low levels. There was a return to pre-treatment levels later than was observed for the columnar cells. The present results on the pattern of response of goblet cells and those of brush border enzyme activity are consistent with the hypothesis that ionizing radiation can influence differentiation. In fact during the first hours after irradiation an early induction of differentiation is evident while during the early repopulation phase columnar cells prevailed relative to the goblet cells. Only at later times were normal differentiation patterns seen. Groups of animals exposed to the same dose of radiation at different times of the day showed similar general patterns of behaviour even if the group irradiated at midnight showed a more marked and longer lasting injury.

Radiotherapy in the aged

Radiation therapy fulfills all the requirements to be used with curative or palliative intent in nearly every case of cancer in the elderly. Radiotherapy is not associated with acute mortality in older persons and can permit organ and tissue preservation. The modern modalities to deliver radiotherapy treatment permit a large sparing of normal tissues. We need major information on proliferative activity of normal tissues and cancer in the elderly, on results according to stage of tumors, and on acute and late sequelae according to performance status of the patient. It is mandatory to perform prospective studies in order to work out protocols for oncologic treatments and specifically for radiotherapy, to treat adequately an increasing part of population.

Cell kinetics in rat small intestine after exposure to 3 Gy of gamma-rays at different times of the day

Qualitative and quantitative morphological changes in rat jejunum were studied after a whole-body exposure to 3 Gy of gamma rays. Four groups of animals were irradiated at different times of the day, namely midnight, 06.00, 12.00 and 18.00 hours. The number of epithelial cells, labelling and mitotic indices were evaluated in crypt sections and the spatial distribution of S-phase cells was determined. At 12 h after irradiation a marked reduction was observed in all parameters, but the proliferative activity was restored quickly and at 36 h after irradiation the values were significantly higher than the controls. The frequency distribution of labelled cells at different positions in the crypt was reduced at 12 h but a clear expansion of S phase cells to positions near to the crypt villus junction was observed during the recovery phase. The animals irradiated at different times of the day showed a similar general post-irradiation response in the number of cells along the side of the crypt, labelling and mitotic indices and in the distribution of S phase cells along the crypts. It is worth noting that the animals exposed at midnight had a distribution of S phase cells similar to controls at 72 h post-irradiation, i.e. earlier than the other groups.

Evidence of reciprocity of bcl-2 and p53 expression in human colorectal adenomas and carcinomas

Evidence of accumulating for the failure of apoptosis as an important factor in the evolution of colorectal cancer and its poor response to adjuvant therapy. The proto-oncogene bcl-2 suppresses apoptosis. Its expression could provide an important survival advantage permitting the development of colorectal cancer. The expression of bcl-2 and p53 was determined by immunohistochemistry in 47 samples of histologically normal colonic mucosa, 19 adenomas and 53 adenocarcinomas. Expression of bcl-2 in colonic crypts > 5 cm from the tumours was confined to crypt bases but was more extensive and intense in normal crypts < 5 mm from cancers. A higher proportion of adenomas (63.2%) than carcinomas (36.5%) expressed bcl-2 (P < 0.05). A lower proportion of adenomas (31.6%) than carcinomas (62.3%) expressed p53 (P < 0.02). A total of 26.3% of adenomas and 22% of carcinomas expressed both bcl-2 and p53. To determine whether these samples contained cells which expressed both proteins, a dual staining technique for bcl-2 and p53 was used. Only 1/19 adenomas and 2/53 carcinomas contained cells immunopositive for both bcl-2 and p53. Moreover there was evidence of reciprocity of expression of bcl-2 and p53 in these three double staining neoplasms. We suggest that bcl-2 provides a survival advantage in the proliferative compartment of normal crypts and colorectal neoplasms. However, its expression is lost during the evolution from adenoma to carcinoma, whereas p53 expression is increased, an event generally coincident with the expression of stabilised p53, which we presume to represent the mutant form.

Helicobacter pylori and cell proliferation of the gastric mucosa: possible implications for gastric carcinogenesis

OBJECTIVES

Helicobacter pylori infection is recognized as a risk factor for gastric adenocarcinoma. "Mitogenesis increases mutagenesis," so the effects of H. pylori infection on the gastric mucosal proliferative compartment have been investigated.

METHODS

In 25 H. pylori-positive and 19 H. pylori-negative subjects, epithelial cell proliferative activity and the pattern of the proliferative compartment were separately evaluated in relation to both the different type of mucosa (antrum and corpus) and the H. pylori positivity/negativity after 3H-thymidine labeling.

RESULTS

Both mucosal cell kinetics and the pattern of the proliferative compartment in the antrum appeared different from those of the corpus. Comparing H. pylori-positive and H. pylori-negative subjects, differences were detected only in the total number of cells in the antrum, whereas all of the cell kinetics parameters, except the labeling index, were greater in the corpus of the former group. A superficialization of the proliferative compartment was shown in H. pylori-positive subjects. Changes were more evident in subjects with more severe gastritis but were also present in H. pylori-positive subjects without corpus gastritis.

CONCLUSIONS

These results show that H. pylori infection is associated with modifications in the proliferative compartment of the gastric mucosa. Both infection per se and chronic gastritis seem to be relevant for such changes.

Proliferative activity in normal colon mucosa and tumor tissue: clinical implications

The study deals with the analysis of proliferative activity in colon carcinomas and adjacent normal appearing mucosa, evaluated with in vitro 3H-Thymidine and autoradiography. In the colonic mucosa no significant differences in 3H-Thymidine Labelling Index (TLI) were observed in relation to the distance of the sample from the neoplasia. The distribution of S-phase cells along the crypt length is low at the bottom, increases rapidly with a maximum within the lower 25% and decreases in the highest positions. When the proliferative activity is increased there is the possibility of expanding the proliferative compartment towards the luminal region of the crypt. The division of the crypt into 5 parts makes it possible to identify 2 different patterns: the first with a very high TLI in the lower fifth, then a sharp decrease and without labelled cells in the highest parts; the second with labelled cells present also in the luminal fifth. These 2 aspects are characteristic of specimens with the lowest and the highest TLI values respectively. The analysis of TLI in colo-rectal cancers shows that cell kinetics parameters are not related to clinical and histopathological features such as sex, age, Dukes and TNM stages and grade of differentiation.

Cell kinetics in breast cancer

In breast cancer the study of prognostic factors has been well developed during last years and many biologic and biochemical parameters have been analyzed. Cell kinetics parameters demonstrated the capability to select patients with different risk of evolution of the neoplasia and in some cases treatment protocols are established by means of proliferation rate. The present study deals with the determination of Thymidine Labelling Index in breast tumors mostly T1-T2 with negative lymph nodes. Results demonstrated that the proliferative activity is higher in younger patients, in T2 cancers compared to T1, and in ductal infiltrating forms compared to the other more frequent histotypes. A significant correlation has been observed between TLI and nuclear grade. The preliminary analysis of the prognostic value of TLI has been two performed using an experimental cut off that is able to discriminate groups of patients with overall survival rate of 67% and 88%, depending on the different proliferative activity of the tumor.

Cell kinetics of melanocytes in common and dysplastic nevi and in primary and metastatic cutaneous melanoma

The 3H-thymidine labelling (LI) and mitotic (MI) indexes were calculated in 29 cutaneous melanocytic lesions: 6 common nevi (CN), 11 dysplastic nevi, subclassified as nevi with architectural atypia (NAA = 4) and nevi with cyto-architectural atypia (NCAA = 7), 2 melanomas in situ (MIS), 4 invasive superficial spreading melanomas (IM) and 6 metastatic melanomas (MM). The LI mean values resulted to be: CN = 0.23%, NAA = 0.98%, NCAA = 1.79%, MIS = 5.75%, IM = 5.16%, MM = 3.80%. In CN, NAA, NCAA and MIS, these values were calculated at epidermal level; in IM and MM at dermal level. At dermal level, the LI mean values of CN, NAA and NCAA were: 0.20%, 0.20%, 0.23% respectively. The MI mean value was close to 0 in CN, NAA, NCAA, MIS; 0.18% in IM, 0.16% in MM. Confirming a low proliferative activity in CN and a high activity in melanomas (MIS, IM, MM), the results showed that dysplastic nevi (NAA, NCAA) had a proliferative activity intermediate between common nevi and melanomas. The lesions with melanocytic atypia (NCAA) resulted to have a higher proliferative activity than those without this histological feature (NAA).

Time-dependent sensitivity of rat CFU-GM to total body irradiation

BACKGROUND

It has been shown that the light-darkness cycle affects the proliferative activity of the hemopoietic system, possibly acting on the distribution of the cells in the cell-cycle phases at different hours of the day. This could determine time-dependent modifications in ionizing radiation damage to hemopoietic progenitors.

METHODS

In this study the influence of the irradiation time on the radiosensitivity of rat CFU-GM was assessed by in vitro clonogenic assay. Rats were exposed to 3 Gy gamma rays at four time points (00:00, 06:00, 12:00, 18:00 hours). Bone marrow CFU-GM cultures were performed at various intervals ranging between 12 hours and 45 days after irradiation and compared with unirradiated controls.

RESULTS

A marked decrease of femoral CFU-GM was observed in the five days following total body irradiation, regardless of the irradiation time point. From this interval on all the irradiated groups showed an increasing proliferation of CFU, which was particularly evident in the group irradiated during the day light period. At the latest intervals (45 days) the post-acute damage to hematopoietic progenitors lacked any evidence of time dependence.

CONCLUSIONS

With the experimental model used, time scheduling does not seem to affect markedly either the acute depletion of CFU-GM in the 5 days following total body irradiation or the late consequence to the CFU-GM compartment.

Gastric cell proliferation kinetics and bile reflux after partial gastrectomy

Thirty-four randomized, partially gastrectomized subjects (12 with a Billroth II, 11 with a Billroth I, and 11 with a total biliary diversion reconstruction) were studied in order to assess the relationships between bile reflux, gastric histology, and cell proliferation kinetics. Bile acid quantity and concentration in the gastric aspirates progressively decreased from Billroth II to Billroth I to total biliary diversion (after which reflux was almost absent). Perianastomotic mucosa in Billroth II subjects showed the greatest degree of foveolar hyperplasia, and this decreased markedly with increasing distance from the anastomosis. Hyperplastic changes were less evident in Billroth I, and virtually absent in total biliary diversion subjects. The overall foveolar hyperplasia-like behavior of cell kinetic parameters (total pit cell number, labeled pit cell number, and labeling index) was shown. Moreover, subjects with mean bile acid concentration greater than 150 mumol/L had both a greater prevalence of foveolar hyperplasia and greater values of cell kinetic parameters than those with mean bile acid concentration less than or equal to 150 mumol/L. A superficialization of the proliferative compartment was also evident in the former group. These results show a close relationship between postgastrectomy bile reflux, foveolar hyperplasia, and cell kinetic parameters. Histologic and cell kinetic findings are probably the expression of gastric adaptation to chronic bile reflux exposure. Moreover, the type and entity of cell kinetic involvement and its relationship to foveolar hyperplasia and reflux may suggest new "tools" in post-gastrectomy surveillance and help to clarify patterns of gastric carcinogenesis.

Labeling index in squamous cell carcinoma of the larynx

Two cell kinetic parameters, the 3H-thymidine labeling index (TLI) and the mitotic index (MI), were studied in vitro on fragments of squamous cell carcinoma tissue of the larynx. They were evaluated to identify those elements able to characterize the growth of these solid tumors. The values of these parameters were analyzed as a function of the clinical stage and the involvement of the regional lymph nodes. Results showed a statistically significant increase in the TLI from stage T1 to T3. No statistically significant differences in the TLI values were observed between the patients with positive and negative lymph nodes.

Polyamine content as a marker of radiation injury in the rat spleen

The modifications of the polyamines putrescine (put), spermidine (spd) and spermine (spm) in rat spleen after 3 Gy whole-body irradiation were studied. Rats were irradiated at four different times of the day (00.00, 06.00, 12.00 and 18.00) and sacrificed between 12 h and 62 days after irradiation. Control animals, sacrificed at the same times of the day, showed higher levels of the spd/spm ratio during the hours of light. After irradiation the polyamine content was rapidly and significantly reduced over a period of 20 days. The modification of the amount of spm lasted for a longer period of time. Normal values of polyamine content were reached at later times when the mitotic activity was restored. The results show a close correlation between polyamine concentration and [3H]thymidine uptake.

Brush border intestinal enzymes after multiple daily fractionation

The modifications in brush border enzyme activity of the epithelial cell of the small intestine were studied after multiple daily fractionation (MDF) of 3 Gy X and 3 Gy X 2 X 2 (12 h split). Disaccharase and dipeptidase activities changed in the same way after irradiation. The results show that both total doses caused the three known phases of increase, decrease, and a return to normal. With MDF, activity at the end of irradiation was similar to or greater than that of controls and remained higher longer than a single dose of 8 Gy. However, the return to normal occurred sooner than after a single dose of 8 Gy. After 11 days, circadian oscillations of brush border enzyme activity appeared similar to those of controls in many segments of the intestine, reaching the highest activity during the night and the lowest in the afternoon.

Cell proliferation and differentiation in the small intestine after irradiation with multiple fractions

Qualitative and quantitative morphologic changes in rat small intestine were studied after abdominal exposure to multiple fractions of gamma radiation. One group of animals received 3 X 2 Gy with one fraction every 4 hours. Another group received two courses of this type with a 16 hour interval between the courses (total dose 6 X 2 Gy). A marked decrease in the number of crypt epithelial cells, and in mitotic and labelling indices, was observed up to 24 to 36 hours after the end of both regimens. Repair and recovery occurred within 72 hours after the end of the last exposure, and the epithelium regained normal morphology. At 1 and 4 hours after the end of the treatment the frequency of S-phase cells along the crypt was greatly reduced and at the following intervals labelled cells occupied the region where differentiation occurs in control animals. During recovery labelled cell distribution showed a gradual return to normal. No substantial differences between the effects of total doses of 6 and 12 Gy were shown except for a greater reduction in crypt epithelial cells at the early time intervals after the larger dose.

Quantitative changes in the goblet cells of the rat small intestine after irradiation

In order to evaluate the process of cell differentiation in the crypt of the rat small intestine the goblet cells were quantitatively studied in controls and after irradiation of the abdomen. The effect of a single dose, administered at 4 different times of the day, and multiple daily fractionations (MDF) of 6 and 12 Gy with different doses per fraction and different time intervals, were compared. Both regimens caused an initial increase of the goblet cells (both in absolute and relative terms), followed by a decrease and finally return to nearly control levels. After MDF the increase was more marked and the return to a normal level occurred earlier than after the single dose.

Qualitative and quantitative effects on the morphology of the small intestine after multiple daily fractionation

The behaviour of qualitative and quantitative morphologic parameters in rats exposed on the abdomen only to multiple daily fractionation (MDF) of 3 Gy X 2 and 3 Gy X 2 X 2 with 12 h splits was analyzed. Both doses were sublethal. The number of epithelial cells in the crypts and in the whole formation, the mitotic index, and the labelling index appeared to be markedly reduced at early intervals after irradiation. Repair and recovery quickly led to normal morphology. The effects of an 8 Gy single dose were compared with those from multiple fractionations.

Behaviour of lysosomal enzymes in the small intestine after multiple daily fractionation

Modifications in the activities of some lysosomal enzymes were studied in the small intestine after irradiation on the abdomen by multiple daily fractionation of 3 Gy per fraction every 12 hours. Total doses of 6 and 12 Gy were studied. With lower dose variations were slight. The modifications of acid phosphatase an cathepsin D appeared very low, whereas beta-glucuronidase increased until 72 hours after the last fraction and then returned to control values. With respect to 8 Gy single dose the injury appeared comparatively similar.

Enzyme activities in ageing small intestine and modifications after irradiation

Brush border enzyme activities in control rats of different ages were studied. Disaccharases, dipeptidases and alkaline phosphatase levels were similar in both age groups. When the rats were sacrificed at two different times of the day the activity was significantly lower in the morning than in the evening in both adult and young animals. No similar differences were observed in lysosomal activities. After irradiation the enzyme activities in both groups presented the same patterns although variations were more marked in adult animals. At 120 hrs the tendency to return to control levels appeared less evident in adult rats. Morphologic data confirmed these results.

Behaviour of the proliferative compartment of the small intestine at different times of the day

The modifications of mitotic and labelling indices in animals killed at different hours of the day were analysed. The invertase activity was also assayed. This brush border enzyme, synthetized by the differentiating cells, showed a clear circadian rhythm with a maximum in the night and a minimum near the end of the light period. Mitotic and labelling indices showed the highest activity in the night and at noon. The positions of mitotic and labelled epithelial cells in the crypt were also determined. The frequency of labelled cells in the different positions of the crypt evidenced a shift of these cells towards the crypt-villus junction in the late afternoon with a consequent reduction of the differentiating compartment.

Modifications of S-phase cell distribution in the intestinal crypts after multiple daily fractionation

The effects obtained by multiple daily fractionation (3 Gy X 2 or 3 Gy X 2 X 2) on the distribution of S-phase cells along the crypt of the small intestine were investigated. The frequency of labelled cell distribution was reduced at early intervals; then the proliferating compartment gradually extended to the villus junctions. During recovery labelled cell frequency in the lower half of the crypts returned to control levels, while labelled cells were present in the differentiating area. With lower total dose modifications were milder and, as early as 72 h before exposure, distribution was already similar to controls. Invertase activity showed an initial increase and a higher reduction during acute damage when fractionation with higher doses was used. A lack of return to normal activity was present even 11 days after exposure when, however, the characteristic circadian pattern was observed.

S-phase cell distribution in the small intestine irradiated at different times of the day. II. Recovery phase

Modifications occurring during recovery in the small intestine of animals exposed to the same radiation dose given at different times of the day were evaluated. S-phase cell distribution along the crypts and invertase activity were evaluated to ascertain the functional capacity of epithelial cells. In animals killed between 5 and 6 days after exposure, S-phase cell distribution and functional conditions tended towards normality although recovery was not complete. Labelled cells occurred also at villus junctions, demonstrating limitation in size of the differentiating compartment. This was confirmed by reduced activity of the brush border enzymes. Animals irradiated at the end of the dark period recovered more quickly and efficiently. In this group, labelled cell distribution was almost the same as in the controls starting from 120 h, and invertase activity was also closer to the controls than in any other group.

S-phase cell distribution in the small intestine irradiated at different times of the day. I. Acute irradiation injury

The S-phase cell distribution has been analysed to evaluate the behaviour of proliferative cells in the intestinal epithelium after irradiation at different times of the day. A marked reduction of S cell frequency was observed at early intervals after abdominal irradiation; this reduction was particularly evident in the lower half of the crypts. At subsequent intervals a progressive extension of the proliferative compartment, with labelled cells also at the top of the crypt, was present. The irradiated groups generally showed a homogeneous behaviour even if a more marked reduction in S-phase cells was observed in group C. The invertase activity, a brush border enzyme synthetized during the differentiation process, presented a different behaviour at the early intervals in the irradiated groups. When the extension of the proliferative compartment occurred the invertase activity reached values close to zero. The modifications in brush border enzymes and in S-phase cell distribution, at early killing times, led to the hypothesis of an early differentiation.

Irradiation at different times of the day. Morphology and kinetics of the small intestine

Rats were irradiated at different time of the day with sublethal doses on the abdomen only, and qualitative and quantitative morphologic modifications were determined. The experiments seemed to be demonstrate that in the groups irradiated at night and at the end of the light period early injury is not severe whereas in the group irradiated at the end of the dark period repair of the injury seems to be more effective.

Modifications in the brush border enzymes of the small intestine after irradiation at different times of the day

The behaviour of the brush border enzyme activity of the intestinal epithelium after the same sublethal radiation dose to the abdomen at different times of the day was investigated. Three previously observed post-irradiation phases (initial increase of activity, reduction and the return to control values) were confirmed, although with some differences. A later return to normal of lactase was also confirmed. The same dose produced different behaviour of the enzyme activities both during the initial and the recovery phase, depending on the time of the day when irradiation was performed, i.e. on the functional condition of the epithelial cells.

14C leucine uptake in rat tissues at different times after irradiation

The uptake of 14C leucine administered at different intervals after irradiation, but always 4 and 8 h before the animals were killed, has been evaluated in tissues with different proliferative activity and protein synthesis. The results have demonstrated an increased uptake and a more rapid elimination of the tracer after irradiation. In the small intestine a lower amount of TCA insoluble fraction was observed when the morphologic injury was evident, while protein synthesis significantly increased during the initial phase of appearance of the injury and mainly during the recovery phase of epithelial cells. Kidney and plasma had levels higher than controls at all intervals.

Radiation effects on the parotid gland of mammals. Part 4: Biochemical and morphological changes after local irradiation

A morphological and biochemical study was done on rat parotids to evaluate the modifications after 2400 rad in the parotid area only. As previously observed, whole-body irradiation with lower doses produced only slight effects on the gland. The enzymes peculiar to glandular function decreased significantly 3 days after irradiation, later they fluctuated on control values. Increase in alkaline phosphatase, LAP, and decrease in protein content was a constant result. Beta-glucuronidase only among lysosomal enzymes increased significantly at some intervals. Morphological alterations in the glandular sections of the sacrificed animals appeared modest and mostly consisted of progressive fibrosis.

Radiation effects on the parotid gland of mammals. Part 3: Behaviour of enzyme activity after irradiation

Modifications of some enzyme activities in parotid tissue homogenates have been studied in animals which were also examined for morphological changes and for plasma and parotid amylase activity. Results from irradiated animals show a certain increase in maltase activity. Alkaline phosphatase and LAP show no significant variations; a similar behaviour is shown by lysosomal enzymes and protein content. A different pattern was seen by comparing the curves of these enzymes with those of the same activity in the small intestine. This result appears to be due to the different radiosensitivity of these tissues.

Radiation effects on the parotid gland of mammals. Part 2: Modifications of plasma and parotid amylase activity

The early modifications of the activity of plasma and parotid amylase have been evaluated in rats after whole-body irradiation in different experimental conditions. The modifications observed in the rat are less evident than in humans. The results have shown an initial decrease and a subsequent increase appearing significant 74 hours after irradiation. This could be due to a direct action of ionizing radiation on the parotid glands. However we cannot exclude that the increase of alpha-amylase could be determined by the intestinal radiation syndrome. In fact, this syndrome leads to a reduced food uptake, and consequently alpha-amylase could accumulate in parotids.

Radiation effects on the parotid gland of mammals. Part 1: Modifications on the morphology and uptake and elimination after 14C-leucine administration

U-14C-Leucine uptake and eliminaton in connection with morphological investigations after sublethal doses have been studied. The tracer uptake and elimination curves do not show significant differences between controls and irradiated animals, except for early appearance of initial peaks. An increased uptake of labeled amino acid was observed only 32 and 120 hours after irradiation, when sacrifices were done at the same hours of the day. The dose employed does not seem to affect in any significant way either the acinar and duct cells or other structures. Only a mild thickening of the connective tissue has been observed in the parotid of animals sacrificed at longer intervals.

Early effects in kidney enzyme activities after irradiation

Brush border enzymes of proximal tubules, lysosomal activities and protein content of rat kidney were analysed after whole-body irradiation using two different experimental schedules. Maltase, alkaline phosphatase and beta-glucuronidase activities increased moderately during the first days after irradiation, whereas LAP, cathespsin D activities and protein content were not modified. No evident morphologic alterations were observed.