Biomedical subjects

N Gale

Publications and source records attributed to N Gale.

At least 19 recordsLinked to original sources

PubMed2000

Wegener's granulomatosis in the upper respiratory tract.

Wegener's granulomatosis is a distinct clinico-pathological entity characterised by necrotising vasculitis of small arteries and veins in conjunction with the formation of granuloma in the upper and lower respiratory tracts, and glomerulonephritis. The vast majority of patients have antineutrophil cytoplasmic antibodies in the serum with a characteristic cytoplasmic pattern. However, in early phases of the disease only the upper respiratory tract may be affected, clinical and histological features may be nonspecific, and antineutrophil cytoplasmic antibodies not present. In this paper we present four patients with involvement of the upper respiratory tract suspicious for early Wegener's granulomatosis. We emphasise the significance of clinical, histological and serological parameters in the early detection of Wegener's granulomatosis.

Aged↗

PubMed2000

Eph receptors and ephrin expression in cranial motor neurons and the branchial arches of the chick embryo.

Cranial motor axons navigate along a variety of pathways to their targets in the periphery of the head. Whereas somatic motor axons innervate tongue and eye muscles, visceral motor axons innervate parasympathetic ganglia, and branchiomotor axons innervate the branchial arches. The formation of these diverse pathways must depend upon molecules present in the environment traversed by growing axons. We have analyzed the potential roles of the ephrin ligands and their Eph tyrosine kinase receptors during cranial motor neuron development and axon pathfinding, by investigating expression patterns of these molecules at relevant stages in the chick. We detected expression of EphA3 and EphA4 among trigeminal and facial motor neurons, at times when these neurons are projecting to their muscle targets in the branchial arches. Corresponding ephrin-A ligands for these receptors were found to be expressed in specific regions of the arches during the same period, implicating ephrin-mediated interactions in cranial motor axon pathfinding.

Animals↗

PubMed2000

Clinical applicability of the Ljubljana classification of epithelial hyperplastic laryngeal lesions.

The diagnosis, prognosis, and choice of treatment of various laryngeal lesions depends almost entirely on the interpretation of changes in the covering epithelium. These abnormalities, referred to as epithelial hyperplastic laryngeal lesions, have been graded according to the Ljubljana classification into simple, abnormal and atypical (risky epithelium) hyperplasia and carcinoma in situ. The aim of this study was to evaluate the clinical applicability and prognostic value of this classification and to determine the incidence of malignant transformation. A retrospective clinical-pathological analysis was performed in a series of 4167 patients with 4574 biopsies, treated from 1979 to 1994. Simple (benign prickle cell) hyperplasia was the predominant grade in nodules, polyps, Reinke's oedema, granulomas, and papillomas, accounting for 37.6-68.6% of cases. In chronic laryngitis, abnormal (benign basal cell) hyperplasia was predominant with 43.9% of cases. Atypical ('risky') hyperplasia was observed almost exclusively in patients with chronic laryngitis (16.1%) and papillomas (10.1%), and only exceptionally in patients with vocal cord nodules (0.9%) and Reinke's oedema (0.3%). The percentage of malignant transformation in atypical hyperplasia was 11.6% (13/112 patients in 2-12 years), while in simple and abnormal hyperplasia, it was 0.3% (8/2920 patients in 1.5-11 years). The data support the concept of the Ljubljana classification dividing epithelial hyperplastic laryngeal lesions into benign (simple and abnormal hyperplasia), potentially malignant (atypical hyperplasia) lesions and carcinoma in situ.

Adolescent↗

PubMed2000

The Ljubljana classification: a practical strategy for the diagnosis of laryngeal precancerous lesions.

There is no internationally accepted classification of epithelial hyperplastic laryngeal lesions (EHLL). The majority of current classifications follow criteria similar to those commonly used for cervical epithelial lesions. However, the different etiology of laryngeal cancer and its particular clinical and histologic features necessitate a grading system more appropriate to this region. The Ljubljana classification of EHLL was devised in 1971 to cater to this requirement. Detailed criteria for histologic grading in this classification were formulated by a working group on EHLL of the European Society of Pathology in 1999. The system recognizes four grades: simple and abnormal hyperplasia are benign categories; atypical hyperplasia ("risky" epithelium) is potentially malignant, and carcinoma in situ actually malignant. The main features by which the proposed grading system differs from other classifications are: 1. the distinction between benign and potentially malignant lesions; 2. the positive separation of carcinoma in situ from atypical hyperplasia; 3. the lack of prognostic significance for any surface keratin layer. The eventual outcome of EHLL patients so graded justifies the proposal for separating the lesions into a benign group, showing malignant transformation in only 0.9% of cases, from a potentially malignant group showing malignant transformation in 11% of cases. For diagnostically difficult cases, supplementary techniques such as those using morphometry, immunohistochemical and molecular biology are advised to improve the accuracy of diagnosis and predictions of their biological behavior.

Carcinoma in Situ↗

PubMed2000

Chromosomes 7,17 polysomies and overexpression of epidermal growth factor receptor and p53 protein in epithelial hyperplastic laryngeal lesions.

PURPOSE: To visualize directly a sequence of genetic changes underlying the entire spectrum of epithelial hyperplastic laryngeal lesions (EHLL) and laryngeal cancer by the use of non-isotopic in situ hybridization (ISH) for chromosomes 7 and 17 in correlation with overexpression of p53 protein and epidermal growth factor receptor (EGFR). The specific aim was to compare the results and prognostic significance between the two types of EHLL: isolated, mainly atypical hyperplasia or risky epithelium, and EHLL associated with squamous cell carcinoma (SCC). PATIENTS AND METHODS: 59 tissue specimens of EHLL obtained from 34 patients, graded according to the Ljubljana classification into simple (SH), abnormal (AbH) and atypical hyperplasia (AtH), and carcinoma in situ (CIS) were included in the study. Non-fluorescent ISH for chromosomes 7 and 17 was performed by biotinylated alpha-satellite DNA probes. Immunohistochemical staining for EGFR and p53 protein was analyzed on the same tissue samples. RESULTS: Polysomy for both chromosomes increased in correlation with progressive grades of EHLL. The most important finding was the statistically significant difference in chromosome copy numbers between the isolated AtH and AtH associated with SCC. Overexpression of EGFR and p53 protein was found in 61 (36/59) and 52% (31/59) of cases, respectively. The immunoreactivity for both markers increased with the grade of lesions, but the staining pattern was not so uniform in isolated EHLL. On the other hand, the immunoreactivity was expressed more constantly in EHLL adjacent to SCC. CONCLUSIONS: Numerical changes in chromosomes 7 and 17 might be associated with an upregulation of EGFR and p53 genes, and could contribute to critical events in laryngeal carcinogenesis. For daily practice, the cytogenetic and immunohistochemical analyses could be of assistance in distinguishing between low- and high-risk groups of AtH. However, the isolated forms of atypical hyperplasia need considerable further study by evaluating genetic changes with the described methods regarding their ultimate transformation to carcinoma.

Adult↗

PubMed2000

Laryngeal granuloma: characteristics of the covering epithelium.

The purpose of the present study was to evaluate the biological behaviour of the marginal epithelium, that proliferates and eventually covers laryngeal granulomas, and to reveal the applicability of the recently re-introduced Ljubljana classification when reporting reactive epithelial hyperplastic lesions. A retrospective clinical and histomorphological analysis was performed on 149 laryngeal granuloma biopsies. Epithelial changes were classified according to the Ljubljana classification into normal epithelium; simple, abnormal, or atypical hyperplasia; and carcinoma in situ. Atrophic epithelium, not evaluated separately in the Ljubljana classification, was additionally assessed. Simple hyperplasia was found in 98 cases (65.8 per cent), abnormal hyperplasia in seven (4.7 per cent), atrophic epithelium in 24 (16.1 per cent), and normal squamous epithelium in 20 (13.4 per cent). Atypical hyperplasia and carcinoma in situ were not observed. The results of our study clearly showed that the proliferation of the covering epithelium mostly in the form of simple hyperplasia, is entirely reactive and therefore reversible. No epithelial hyperplastic lesions were found that were previously described to be associated with an increased risk of malignant alteration, namely atypical hyperplasia and carcinoma in situ. However, since an initial growth of an invasive malignant neoplasm might macroscopically imitate the appearance of laryngeal granuloma, a histological examination in all aetiological forms of laryngeal granulomas is required. By clearly discerning the benign nature of epithelial changes in laryngeal granulomas, the recently re-evaluated and further formulated Ljubljana classification may also influence the clinical handling of patients.

Adolescent↗

PubMed2000

Rapid extraction of DNA from archival clinical specimens: our experiences.

The analysis of DNA extracted from archival clinical specimens using polymerase chain reaction represents the basis of a variety of research and diagnostic protocols in medicine. However, the selection of optimal DNA extraction method is critical if such an analysis is to be successful. Recently, we have evaluated a number of rapid DNA extraction protocols in order to find the most suitable method for routine processing of the most common archival materials in pathological and cytological laboratories: paraffin-embedded tissues and Papanicolaou- or Giemsa-stained smears. Our results demonstrate that rapid DNA extraction methods have comparable DNA extraction efficiencies with standard DNA isolation protocols on archival clinical specimens with the exception of Giemsa-stained smears.

Archives↗

PubMed2000

A mouse model of chronic bacterial lesions (a cotton trap) for studying oral bacteria-lymphocyte interactions.

We established a mouse model of chronic bacterial infection (cotton trap) to get a deeper insight into interactions between immune cells and bacterial strains, that are most commonly isolated from periapical processes. We have used flow cytometry to identify the presence of intracellular cytokines of activated T cells collected from cotton traps, previously infected with different strains of bacteria and implanted subcutaneously into the back of the mice. We provide an evidence that anaerobic bacteria (Bacteroides sp.) and nocardiae are more effective in inducing cytotoxic immunity and Th1 response compared to oral streptococci. Differences in immune response against anaerobic bacteria when compared to streptococci are probably dependent on some non-specific immune cell stimulation (e.g. by bacterial cell wall components), nevertheless the role of specific antigen-dependent immune mechanism can not be excluded.

Animals↗

PubMed1999

Criteria for grading in the Ljubljana classification of epithelial hyperplastic laryngeal lesions. A study by members of the Working Group on Epithelial Hyperplastic Laryngeal Lesions of the European Society of Pathology.

AIMS: To validate histological criteria for the grading of epithelial hyperplastic laryngeal lesions (EHHL) (dysplastic laryngeal lesions), we used a system that had been devised and tested in Ljubljana, Slovenia over many years and was felt to be more appropriate to laryngeal pathology than is the commonly-used model of intraepithelial neoplasia in the cervix. METHODS AND RESULTS: Vocal cord biopsies of 45 patients with a broad spectrum of EHLL were reviewed. Detailed histological criteria were formulated for each of the four grades of EHLL in the Ljubljana classification, comprising simple hyperplasia (benign spinous layer augmentation), abnormal hyperplasia (benign basal and parabasal layer augmentation), atypical hyperplasia (risky for malignancy) and carcinoma in situ (actually malignant, but without invasion). CONCLUSIONS: Using these criteria a high degree of concordance of histological diagnoses of grading levels for the Ljubljana classification was achieved between the pathologists of the Working Group. The system was found to be more precise for routine diagnostic work than the others in vogue. The different grades of the Ljubljana classification correspond to significantly different levels yielded in each grade by the semiobjective methods of quantitative morphometry and immunohistochemistry.

Epithelium↗

PubMed1999

Authors' reply

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Journal Article↗

PubMed1999

Cervical metastases of head and neck squamous cell carcinoma correlate with loss of heterozygosity on chromosome 16q.

To assess the potential involvement of putative tumor suppressors or metastasis suppressors on chromosome 16q in head and neck squamous cell carcinoma (HNSCC), we have examined 42 primary HNSCCs for loss of heterozygosity (LOH) at 16q and correlated these findings with the occurrence of cervical nodal metastases and other clinical parameters. Seven of the 42 (17%) HNSCCs examined displayed LOH at chromosome 16q24. Three of the seven HNSCCs showed LOH at all of the informative loci analyzed along the chromosome arm, whereas the other four showed only loss of a subset of markers. When LOH at 16q was correlated with clinical parameters, there was no significant correlation with age, sex, clinical stage, T stage, N stage or survival. However, there was a correlation between LOH at chromosome 16q24 and involvement of cervical lymph nodes. Of the seven HNSCCs that had lost heterozygosity at 16q24, six had local metastases to lymph nodes indicating that LOH at 16q24 may have predictive value for the metastatic potential of HNSCCs.

Adult↗

PubMed1998

Detection of human papillomaviruses in tissue specimens.

During the past decade, molecular methods based on the detection of viral DNA have become a key tool for the detection of human papillomaviruses (HPVs) in tissue. The methods can be divided into two groups: those in which tissue destruction is unavoidable for the detection of HPV DNA, and those in which the detection of viral DNA is performed in a way that allows tissue morphology preservation. Polymerase chain reaction is currently the most sensitive method for HPV detection and an excellent research tool. However, because of frequent contamination problems and lack of standardization, it is not readily applicable to diagnostic laboratories. The recent improvements in in situ hybridization have made it possible for this method to become the most appropriate method for routine detection of HPVs in tissue. At present, however, the use of at least two independent HPV DNA detection methods is indispensable for accurate determination of HPVs.

DNA, Viral↗

PubMed1997

Quantitative pathology of laryngeal epithelial hyperplastic lesions.

We studied 40 laryngeal biopsies samples in order to ascertain the reliability of light microscopical criteria for subdividing laryngeal epithelial hyperplastic lesions (EHL) and carcinoma in situ as well as to determine the relationship between proliferative activity of their epithelial cells and the histological grade. The biopsies were divided into four groups in accordance with the Kambic-Lenart classification: simple, abnormal and atypical hyperplasia and carcinoma in situ. 10 cases in each group were included. The morphometrical analysis was carried out by a semiautomatic image analysis system. The proliferative activity was determined by the high percentage of cell nuclear antigen (PCNA) and Ki-67 positive epithelial cells and with counting nucleolar organizer regions (Ag-NORs) per nucleus. Our results suggest that measuring the nuclear area of the basal cells. augmented with basaloid cells and carcinomatous cells, is the most useful morphometrical method of differentiating three types of laryngeal EHL and carcinoma in situ, while the proliferative activity progressively increased with the degree of epithelial hyperplasia. Morphometrical methods and proliferative activity should be regarded as useful in conjunction with the traditional histopathological methods allowing more of objective grading of EHL.

Biopsy↗

PubMed1997

Human papillomaviruses: a study of their prevalence in the epithelial hyperplastic lesions of the larynx.

This study investigated the prevalence of human papillomavirus (HPV) infection in various laryngeal epithelial hyperplastic lesions using the Kambic classification from simple hyperplasia to invasive squamous cell carcinoma. For detection of HPV infection polymerase chain reaction (PCR) with 3 different HPV consensus primer sets and in situ hybridization were used. The presence of the HPV DNA was detected in only 2 of the 88 specimens tested: HPV type 6 was detected in 1 case of simple hyperplasia and HPV type 16 in 1 case of invasive squamous cell carcinoma. In conclusion, our study suggests that most laryngeal epithelial hyperplastic lesions are not associated with HPV infection and that other pathogenic mechanisms are more important in the etiology of these lesions.

Carcinoma, Squamous Cell↗

PubMed1997

Langerhans and other immunocompetent cells in vocal cord epithelial hyperplastic lesions of patients with chronic laryngitis.

The aim of the study was to evaluate the intraepithelial and stromal density of Langerhans cells and lymphoid infiltrate in different stages of carcinogenesis in vocal cord biopsies of 24 randomly selected patients with chronic laryngitis. The Langerhans and lymphoid cells were counted using immunolabelling with antibodies against CD1a, S100, CD3, CD20, and CD68 on paraffin-embedded sections of 24 archival laryngeal vocal cord mucosa biopsy specimens, 6 classified as simple, 7 as abnormal, and 11 as atypical epithelial hyperplasia. Results were statistically evaluated using the Kruskal-Wallis and Wilcoxon sign rank tests. The mean number of Langerhans cells and T lymphocytes per mm2 of cross-sectioned epithelium was found to increase from simple to atypical hyperplasia. There were statistically significant differences in Langerhans cell density between atypical hyperplasia and each of the other 2 grades, simple and abnormal hyperplasia, with p < 0.05. Our study suggests the involvement of immune mechanisms, particularly cell mediated, during laryngeal carcinogenesis and the possibility that the assessment of Langerhans cell density might be of prognostic significance.

Adult↗

PubMed1997

Langerhans cells in human papillomaviruses types 6/11 associated laryngeal papillomas.

Some studies have shown a reduced density of Langerhans cells (LCs) within epithelium infected by human papillomaviruses (HPV) types 16/18. However, data on a correlation between HPV types 6/11 infection and LCs have been missing. To solve this problem, we analysed 24 biopsy specimens of laryngeal papillomas, selected randomly, 20 multiple and 4 solitary. The presence of HPV 6 and 11 was proven by polymerase chain reaction (PCR) using 2 different sets of primers in 23 biopsy specimens. Abnormalities of the covering stratified squamous epithelium were graded according to the Kambic-Gale classification. LCs were immunohistochemically labelled with 2 different antibodies, CD1a and S100. Quantitative analysis was performed to determine the density of LC per mm2 in different grades of epithelial abnormalities covering laryngeal papillomas. Although no statistically significant differences in the mean number of LCs per mm2 of the cross-sectioned epithelium covering laryngeal papillomas were observed comparing simple, abnormal and atypical hyperplasia groups, the mean number of LCs per mm2 in laryngeal papillomas associated with HPV types 6/11 infection substantially exceeded that of the vocal cord surface epithelium in patients with chronic laryngitis.

Adolescent↗

PubMed1997

Epidermal growth factor receptor, c-erbB-2 and p53 overexpressions in epithelial hyperplastic lesions of the larynx.

An immunohistochemical analysis of overexpression of epidermal growth factor receptor (EGFR), c-erbB-2, and p53 proteins was performed on 43 biopsies of laryngeal epithelial hyperplastic lesions (EHLL), classified according to the Kambic-Lenart classification, and in 11 cases of laryngeal carcinoma (SCCL). The aim of the present study was to determine whether there is a correlation between the staining patterns of these proteins and different grades of EHLL, and to reveal their possible prognostic value. We compared the staining patterns of atypical hyperplasia adjacent to cancer with the same type of lesions which have not turned malignant. p53 and EGFR overexpressions were detected in 28/54 (52%) and 33/54 cases (61%), respectively, and tend to increase with the degree of epithelial changes. The intensity of staining in various grades of EHLL adjacent to cancer was more pronounced than the same type of lesions which have not progressed to cancer. c-erbB-2 was weakly positive in the majority of cases, and changed from predominantly membranous in simple hyperplasia to cytoplasmic staining in abnormal and atypical hyperplasias. There was no significant statistic correlation between the amount of positive cells for all proteins and the grade of epithelial abnormalities. We conclude that the overexpression of each biomarker itself adds little predictive value over routine histomorphology, and cannot be regarded as a reliable prognostic factor for EHLL. However, the histologic characteristics of atypical hyperplasia together with the immunostaining patterns of EGFR and p53 up to two-thirds or more of the epithelial thickness could be considered a reliable pattern which correlates with the progression to cancer.

Carcinoma, Squamous Cell↗

PubMed1997

Correlation of histomorphological criteria used in different classifications of epithelial hyperplastic lesions of the larynx.

Different classifications of epithelial hyperplastic lesions of the larynx were proposed, but none of them has been generally accepted. The basic distinction among these gradings is evaluation of carcinoma in situ as a precancerosis or a distinct and separate entity. In the present study, atypical hyperplasia and carcinoma in situ are evaluated according to the proposed histomorphological criteria of the Kambic-Lenart classification. In an attempt to separate more objectively the histomorphological differences between these 2 lesions, in addition to traditional light microscopical examination, we also performed semiquantitative analysis with statistical evaluation using the Wilcoxon signed rank test. These results revealed a significant morphological and statistical difference comparing atypical hyperplasia and carcinoma in situ on the basis of the following criteria: abnormal mitotic figures (p = 0.005), mitotic activity (p = 0.014), nuclear pleomorphism (p = 0.006), cellular atypia (p = 0.005), dyskeratosis (p = 0.008), and stromal infiltration (p = 0.015). These results confirm our view that atypical hyperplasia and carcinoma in situ are 2 consecutive but different entities in the process of carcinonogenesis.

Carcinoma in Situ↗