1,721,001 research outputs found
Thymidine labeling index in colorectal carcinoma: relation to clinicopathological parameters and to mitotic index
No full textTwo cell-kinetic parameters, the thymidine labeling index (T-LI) and the mitotic index (MI) were determined for a prospective series of 74 primary colorectal cancers. Dukes' stages were used to define the extent of the tumor: 10 tumors were classified as Dukes' A, 36 as Dukes' B, and 22 as Dukes' C. Of these tumors, 14 were well-differentiated, 44 moderately differentiated, and 15 poorly differentiated adenocarcinomas. The H3dT-LI values obtained varied widely, from 2.5 to 38.9% (median value: 16.8%). The MI shows a range of from 0 to 13.2% with a median value of 3.2%. The T-LI values were independent of the sex and age of the patients and of the histological grading and Dukes' stage. Conversely, the MI was related to histological grading. This study indicates that the T-LI, whose application has reached the gold standard, still represents an independent parameter and the most sensible, objective, and specific complementary method for the analysis of the S phase
Densitometric evaluation of DNA content in colorectal cancer
No full textThe aim of the present study was to provide information on the DNA content in colorectal tumours using densitometric techniques on histological samples and correlating the findings with age, sex, histological grade, stage, presence or absence of lymph-node metastasis and survival time. The distribution of DNA values was significantly related with the histological grade. Dukes' stage and infiltration of the peritumoral lymph-nodes. The distribution of DNA values was not significantly correlated with age and sex. From the data obtained in this study it can be concluded that evaluation of DNA content in colorectal adenocarcinoma can be used as a prognostic test that is complementary to histological investigation. The ploidy can provide information for classifying the degree of malignancy and can also be used to determine which tumours are biologically most aggressive
PCNA--a cell proliferation marker in vocal cord cancer. Part II: Recurrence in malignant laryngeal lesions
No full textLaryngeal squamous cell carcinoma constitutes the most frequent carcinoma found in the head and neck region. A precise prediction for recurrence potential cannot be done on site, treatment and histologic grading. Since Proliferating Cell Nuclear Antigen (PCNA) and DNA-cytometry have shown a good correlation between premalignant lesions and their progressive potential towards full-fledged carcinoma in the larynx as described in part I of this work, we have analyzed the PCNA index and DNA cytometry in specimen taken from vocal chord carcinomas with a 5-year follow-up, in order to assess its relationship with the presence or absence of tumour progression. 42 cases with (21) and without (21) recurrence have been examined. The DNA-index ranged from 1.01 to 1.43 (mean 1.10) in the group without and from 1.02 to 1.59 (mean 1.38) in the group with recurrent carcinoma (p = 0.002). The PCNA-index ranged from 0.00% to 18.90% (mean 6.97%) in the non-recurrent group and from 0.00 to 3g.50% (mean 16.35%) in the patients with recurrence (p = 0.001). Both indices also correlated in a highly significant way. From these data emerges a highly significant correlation between the cytometric indices of cell proliferation and PCNA immunostaining. Furthermore the high correlation between PCNA and DNA-index is of special interest for single case assessment. High DNA aberration and PCNA-index in vocal chord carcinoma may indicate a higher cellular aggressiveness of the tumour, resulting in a greater overall risk of metastases and local recurrences. Our results support the thesis that the indices of cellular proliferation within some cancers can define subsets of patients of high risk and help in isolating a population in which a more aggressive clinical protocol may be proposed
Delayed neuronal maturation of the medullary arcuate nucleus in sudden infant death syndrome
No full textRecently, quantitative abnormalities in neuronal populations derived from the rhombic lip (inferior olive nucleus of the brain stem and external granular layer of the cerebellum) have been reported in victims of the sudden infant death syndrome (SIDS). In this study we examined the arcuate nucleus (ARCn) of 35 SIDS victims and 25 controls, to determine neuronal abnormalities involving this nucleus in SIDS. Computer-assisted cell evaluation was made on sections stained with hematoxylin and eosin to study the neuronal dimensions (nuclear and cytoplasmic area, nuclear/cytoplasmic ratio), the form factor and the density of reactive astrocytes. There was a significant reduction of the neuronal area (nuclear and cytoplasmic) in SIDS victims compared with controls. The neuronal populations of SIDS victims had a significantly higher form factor, index of immaturity. The SIDS victims were divided into two groups on the basis of ARCn development: 18 SIDS-A cases with a well-developed ARCn and 17 SIDS-B cases with severe bilateral hypoplasia. The results of our research indicate that the developmental defect is characterized by a reduction in size of the ARC neurons and by neuronal depletion. In SIDS the ARCn has the histomorphological features of neuronal immaturity, and there is a marked reduction of all quantitative cell parameters and lower astrocytes density with respect to controls. On the basis of the morphometric results of the arcuate neuronal populations, we hypothesize that infants whose neurons have failed to reach full maturity are at risk for SIDS because they are unable to develop appropriate cardioventilatory control
Cell kinetics of pleomorphic adenomas of the parotid gland
No full textThe aim of the present study is to characterise the cell kinetics of pleomorphic adenoma of the parotid gland by assessing DNA content and proliferating cell nuclear antigen (PCNA) positivity. In 22 parotid adenomas, DNA content was measured by densitometry in histological serial sections stained with Feulgen's method and PCNA positivity was determined by immunohistochemistry with the monoclonal antibody PC10. To assess the proliferative activity, DNA index and PCNA index were evaluated. It was possible to distinguish two types of adenoma. In Group I there was a prevalence of diploid cells with a low PCNA index. Group II is represented by adenomas with a large percentage of triploid cells and a PCNA index significantly higher than that of Group I. Our findings suggest that the possibility of recurrence or malignant transformation depends on intrinsic biological properties of each adenoma
Exercise rhinomanometric test in the diagnosis of vasomotor rhinopathy
No full textThe Authors examined 55 patients divided into two groups, one of 30 vasomotor rhinopatic patients and the other of 25 normal subjects. The aim of the study was to set up an objective diagnostic rhinomanometer test through observation and evaluation of reaction brought about by physical exertion following an exertion test of 5 minutes which employed a computerized climb simulator. Nasal resistance was measure before and immediately after exertion and then at intervals of 10, 20 and 50 minutes. Our data reveal a noteworthy decrease in nasal resistance brought about by the sympathetic nervous system in normal and rhinopathic subjects. Return to pre-exertion values, however occurred difference in the two groups: in the control group nasal resistance returned to pre-exertion values slowly, while in the rhinopathic group, it decreased rapidly and a rebound effect was observed. In vasomotor rhinopathy the orthosympathetic system is overcome by the para sympathetic system with regard to nasal vascularization control and, therefore, in rhinopatic patients exertion stimulates efficacions activation of the orthosympathetic system a phenomenon which does not occur in healthy subject. On the basis of our results an intensive stimulus such as physical exertion seems to have a different effect on the two groups suggesting that the vessels of nasal mucosa do not always respond in the same way, and that in vasomotor patients there is an alternate reactivity of neural control of nasal mucosa. The rhinomanometric exercise test seems to be useful in revealing this phenomenon and to be diagnostically reliable. The method is easily reproducible, non-invasive and can be usefully applied in clinical practice associated with the normal rhinomanometric challenge test
PCNA--a cell proliferation marker in vocal chord cancer. Part I: Premalignant laryngeal lesions
No full textLaryngeal hyperkeratotic lesions can progress to fully developed malignant carcinoma in some cases. These premalignant lesions are proliferative disorders whose potential for further tumour progression is perhaps difficult to assess by mere histology. Immunostaining with PCNA, a protein correlated with cell proliferation, has been used to study tissue behavior in 30 cases of premalignant laryngeal vocal chord lesions treated by epithelial stripping in microlaryngoscopy, 15 of whom had no progression and 15 had recurrence and final development of full malignancy. The results showed a statistically significantly higher PCNA-index in the cases which underwent further tumour progression towards malignancy. PCNA testing may thus be suggested as a marker for tumour progression potential and help in determining clinical treatment choices
Significance of the DNA synthesis in hypertrophic cardiomyopathies.
No full textDNA content and proliferating cell nuclear antigen (PCNA) expression were investigated in normal hearts, in hypertrophic from hemodynamic overload hearts and in hypertrophic cardiomyopathy (HCM). The aim of this study was mainly to determine whether the hyperdiploid myocardial cells in all cases are in dynamic or static phase. The percentage of PCNA positive cells only in the HCM group was significantly higher (mean value = 25.4%) than the percentage of hyperdiploid cells (mean value = 9.3%). Therefore, the DNA replication occurs through a different process from that of normal cell cycle which lead to an increase in ploidy and eventually mitosis. These data should be interpreted not only as the result of a periodic amitotic DNA renewal and not even as the result of an increased apoptosis, but especially as a repair process of the DNA molecules affected by a various types of damages in HCMs
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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