Larynx morphology and sound production in three species of Testudinidae.

Although the ability to vocalize is widespread among tortoises, the mechanisms of sound production in chelonians remain undescribed. In this study, we analyze the morphology and histology of the larynx of three species of Testudinidae (Testudo hermanni, T. graeca, and T.

Expression of natriuretic peptides, nitric oxide synthase, and guanylate cyclase activity in frog mesonephros during the annual cycle.

Natriuretic peptides (NPs), a family of structurally related hormones and nitric oxide (NO), generated by nitric oxide synthase (NOS), are believed to be involved in the regulation of fluid balance and sodium homeostasis. Differential expression and regulation of these factors depend on both physiological and pathological conditions. Both NPs and NO act in target organs through the activation of guanylate cyclase (GC) and the generation of guanosine 3',5'-cyclic monophosphate (cGMP), which is considered a common messenger for the action of these factors.

Quantification of the DHFR gene in blast cells of leukaemia patients by fluorescence in situ hybridisation.

The fluorescence signal intensity of the DHFR gene was analysed in lymphocytes from 15 normal donors, in MTX-resistant HeLa cells (carrying DHFR gene amplification) and in bone marrow blasts from 16 patients with acute leukaemia (AL) by in situ hybridisation. Our aim was to verify if DHFR gene amplification may be responsible for increased enzyme activity in leukemic cells. The results obtained with a fluorescence in situ hybridisation method were quantified using the Scion image software program and compared with cytochemical and cytophotometric data relating to DHFR activity.

Stem cell recruitment and liver de-differentiation in MMTV-neu (ErbB-2) transgenic mice.

The liver of tumor-bearing hosts manifests fetal phenotypes. We investigated the expression of differentiation markers on the liver in MMTV-neu (ErbB-2) transgenic mice, in the period from incipient neoangiogenesis to lung metastatization. We report AFP expression by hepatocytes in all lobular zones, CD34 cell arrest and subsequent hemopoiesis in periportal and mid-zone areas, oval-like cells (CD34+, CK19+, AFP+) and ductular reaction in portal tracts, portal CK19+ and GGT+ hepatoblast-like cells, and midzonal large dysplastic hepatocytes.

Evaluation of serum levels of cytokines and intercellular adhesion molecule-1 (ICAM-1) in astrocytic tumours.

Soluble form of intercellular adhesion molecules (sICAM) are increased in serum of many inflammatory diseases and tumours: the expression of such molecules is regulated by cytokines. In the present paper serum levels of interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R) and sICAM-1 were evaluated in patients with glioma compared with different tumours (lung and kidney carcinoma) in order to investigate the compromise of the immune system in these malignancies and to understand the host defence mechanisms. 14 cases of astrocytomas (WHO grade II, III), 20 cases of glioblastomas (GBL, WHO grade IV), 5 cases of lung carcinoma and 6 cases of kidney carcinoma were studied; the results were compared with 15 healthy controls.