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Male germ cells undergo different processes within the female reproductive tract to successfully fertilize the oocyte. These processes are triggered by different extracellular stimuli leading to activation of protein phosphorylation. Protein kinase C ( PKC) is a key regulatory enzyme in signal transduction mechanisms involved in many cellular processes. Studies in boar sperm demonstrated a role for PKC in the intracellular signaling involved in motility and cellular volume regulation. Experiments using phorbol 12-myristate 13-acetate ( PMA) showed increases in the Serine/Threonine phosphorylation of substrates downstream of PKC in boar sperm. In order to gain knowledge about those cellular processes regulated by PKC, we evaluate the effects of PMA on boar sperm motility, lipid organization of plasma membrane, integrity of acrosome membrane and sperm agglutination. Also, we investigate the crosstalk between PKA and PKC intracellular pathways in spermatozoa from this species. The results presented here reveal a participation of PKC in sperm motility regulation and membrane fluidity changes, which is probably associated to acrosome reaction and to agglutination. Also, we show the existence of a hierarchy in the kinases pathway. Previous works on boar sperm suggest a pathway in which PKA is positioned upstream to PKC and this new results support such model. [ABSTRACT FROM AUTHOR]

In sows, the oviductal sperm-binding glycoprotein ( SBG), which binds to the periacrosomal region of boar sperm, has been shown to be involved in sperm selection. In this work, we isolated porcine sperm proteins that interact with SBG. One of them is identified as a homologue of human S100 A7 (psoriasin). Anti-human S100 A7 antibodies show that this homologous protein localises to the head of sperm. The isolation of a homologue of S100 A7 based on affinity to SBG and its localisation at the head of sperm leads us to suggest that S100 A7's homologous protein may be involved in the negative selection of sperm by SBG in pigs. Human S100 A7 shows antibacterial properties, particularly over Escherichia coli, a species that has demonstrated deleterious effects on human sperm. We searched for S100 A7 in human sperm and found that it is present and localises at the acrosomal region. Thus, we report the presence of S100 A7 in human sperm and of a homologous protein in pig, with similar localisations. In humans, an antimicrobial role seems likely for psoriasin; in porcine sperm the studied protein binds to SBG suggesting a function in sperm selection, but an antimicrobial function cannot be ruled out. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article on the key role of TP53 and PTEN mutations in treating breast and ovarian cancer published in the previous issue.

A letter to the editor is presented which demonstrates the usefulness of tumor marker CD10 in the diagnosis of morular metaplasia in neoplasm in extragenital locations by studying the immunoexpression of CD10 and ß-catenin in seven cases of tumors.

Describes the case of an old woman who was admitted to the hospital with a mass in the neck. Diagnosis of a cold nodule in the woman's right lobe; Analysis of the spindle cell variant of papillary thyroid carcinoma.

OBJECTIVES: To investigate the artefacts in oral biopsies taken by general dental practitioners (GDP) and oral and maxillofacial surgeons (O&MF) and to assess the concordance of clinical and pathological diagnoses. DESIGN: Cross-sectional investigation. SETTING: Primary care and hospital practice. MATERIAL AND METHODS: A total of 354 randomly selected oral biopsy samples studied by the same pathologist. MAIN OUTCOME MEASURES: Clinical and pathological diagnoses — prevalence and location of surgical handling artefacts: crush, splits, haemorrhage and fragmentation. RESULTS: Artefacts identified in GDPs biopsies: crush 27.1%; haemorrhage 19.8%; splits 11.3%; and fragmentation 6.2%. O&MSs biopsies showed: crush 10.2%; splits 13%; fragmentation 2.3%; and haemorrhage 8.5%. No differences in split or fragmentation were identified between GDPs and O&MSs. Crush (χ² = 16.76; P = 0.000) and haemorrhage (χ² = 9.31; P = 0.003) were more frequently identified in GDPs biopsies. Concordance between clinical and pathological diagnoses was excellent (κ > 0.75) for both groups in all disorders considered. CONCLUSIONS: The elicited clinical knowledge, the quality of the samples sent to the pathologists seem to suggest the advisability for the GDPs to perform diagnostic biopsies. [ABSTRACT FROM AUTHOR]

Aims: To investigate the immunohistochemical and molecular genetic features of the cadherins/catenins complex in thyroid carcinoma based on the hypothesis that poorly differentiated carcinoma of the thyroid represents an intermediate step between well-differentiated and undifferentiated carcinomas. Methods and results: Immunohistochemistry for E-, P- and N-cadherins and α-, β- and γ-catenins was performed in a series of 17 cases of poorly differentiated carcinoma of the thyroid. All cases showed absence of membranous expression of E-cadherin with no aberrant expression of P- or N-cadherins; regarding catenins there was heterogeneous loss of expression with membranous immunolocalization of the three catenins in most cases. Molecular analysis of the E-cadherin gene and exon 3 of the β-catenin gene was also performed by polymerase chain reaction/single-strand conformation polymorphism and sequencing. No mutations in either gene were detected in any case. Conclusions: In contrast to previous reports, our results suggest that loss of E-cadherin rather than β-catenin mutation is the crucial event in determining the differentiation ‘level’ of thyroid carcinomas. [ABSTRACT FROM AUTHOR]

Abstract The common quail (Coturnix coturnix ) is one of the few species in which mate-switching (when different pair bonds are established within a single breeding attempt), has been recorded. In this study, we report the characteristics of pair bonds (description, number of males per female and duration) by monitoring a wild population of common quail (28 females and 49 males) by radiotracking. 57% of the females studied (n = 14) showed mate-switching, whereas 22% of the males were serially polygynous, successively forming pairs with a series of females. The fitness of females with mate-switching, measured in terms of clutch size and hatching success, did not differ from that of females bonded with one male. The analysis of paternity in three families by multilocus DNA fingerprinting revealed genetic polygamy in two of the nests studied. A male sired offspring with two females, and we obtained genetic evidence for intraspecific brood parasitism. We discuss how these behavioural and ecological observations may relate to the particular mating system of the common quail. [ABSTRACT FROM AUTHOR]

Time of day is usually not considered an important factor underlying the structure of forest passerine communities. However, this study shows that the positions exploited in trees by some members of a community change during the day in a cyclic pattern. Coal Tit Pants ater, Crested Tit Parus cristatus and Goldcrest Regulus regulus foraged lower and nearer to the trunk at midday than in the first and last hours of the day. Simultanously, there were diurnal changes in the niche breadth (degree of uniformity in the exploitation of the different parts of the trees). The Coal Tit reached the maximum niche breadth values during the central part of the day, with the minimum being recorded at that time for the Crested Tit and the Goldcrest. On the other hand, Treecreepers Certhia sp. did not show significant diurnal variation. These results, together with the changes in activity levels during the day for each species, suggest that time of day plays an important role in the structure of the community, allowing a more uniform use of the habitat and addressing a new interpretation of the interspeciic relationships inside the community, with competitive relationships not showing the same intensity throughout the day. [ABSTRACT FROM AUTHOR]

Discusses the pathological changes related to Imatinib treatment in a patient with a metastatic gastrointestinal stromal tumour (GIST), a biologically distinctive tumour type different from smooth muscle and neural tumour type. Role played by c-kit expression in the development of the interstitial cell of Cajal; Function mutation of GIST.

Presents several expert views and counterviews on the occurence of a lipomatous haemangiopericytoma of the thyroid, an adipocytic variant of solitary fibrous tumor. Key issues of interest; Analysis of pertinent topics and relevant issues; Implications on histopathology.

Aims: To describe survival from oral metastases, particularly gingival metastases, and to identify clinical prognostic variables., Materials and Methods: A series of 39 patients were studied, analysing age, gender, primary tumour site, oral metastases site and histological type., Results: Mean age: 62.3+/-9.2 years, with similar prevalence by gender. The most frequent sites for primary tumours were the kidney (20.5%), lung (20.5%) and breast (20.5%). Gingival metastases represented 63.6% of all oral soft tissue metastases (7/11). The average time between primary tumour diagnosis and appearance of the gingival metastases was 9.7+/-13.4 months. The median survival time since gingival metastases appearance was 5.2 months [95% confidence interval (CI)=0-13.6]; no statistically significant difference with other oral locations was found by the Kaplan-Meier curves (log rank: 0.29; p>0.05). Oral metastases involving the gingiva were more frequently found in the maxilla (85.7%versus 14.3%), whereas intra-osseous metastatic tumours were more frequent in the mandible (77.8%versus 22.2%; p<0.05; odds ratio=21; 95% CI=2.0-210.1). None of the variables considered had a prognostic value as indicated by the Kaplan-Meier test., Practical Implications: The data in this paper show that 25% (and in other studies up to 37%) of oral metastases came from unknown primary tumours; thus a biopsy with histopathologic analysis is mandatory for every patient with a gingival mass., Conclusions: This study reinforces the significance of gingival metastases as a poor prognosis indicator. Dental practitioners should suspect that gingival masses mimicking benign or inflammatory lesions may represent a sign of underlying malignant tumours.