Mother and daughter with Kenny-Caffey syndrome: the adult phenotype.

Kenny-Caffey Syndrome (KCS) is a genetic syndrome characterized by growth retardation with short stature, cortical thickening and medullary stenosis of long bones, and hypoparathyroidism with hypocalcemia. KCS and the related but more severe condition osteocraniostenosis are determined by monoallelic variants in the FAM111A gene. Here we describe the KCS phenotype resulting from the monoallelic FAM111A variant p.Y511H in a 31-year-old woman and in her 56-year-old mother, who is one of the oldest affected individuals known so far. To our knowledge, it is also one of the few molecularly confirmed cases of a mother-to-child transmission of KCS.

Potential of telomerase expression and activity in cervical specimens as a diagnostic tool.

AIMS: To evaluate the potential use of the immunohistochemical expression of telomerase and the measurement of its activity as diagnostic tools in the uterine cervix. METHODS: The fluorescent telomeric repeat amplification protocol (TRAP) assay was used to evaluate telomerase activity in a series of 43 cervical scrapings. Twenty five cases were cytologically classified as inflammatory, and/or metaplastic, and/or acanthotic, and 18 cases presented cell alterations compatible with mild, moderate, or severe cervical intraepithelial neoplasia (CIN). Immunohistochemistry was performed on a retrospective series of 86 archival, paraffin wax embedded blocks using a recently developed anti-hTERT (human telomerase reverse transcriptase) monoclonal antibody. RESULTS: Telomerase activity was expressed as arbitrary enzymatic units (AEU). Median values were 38.0 AEU for inflammatory non-dysplastic cell specimens, 33.5 AEU for CIN I, 41.0 AEU for CIN II, and 28.0 AEU for CIN III. The median percentage of immunoreactive dysplastic cells, as detected by immunohistochemistry, was significantly (p = 0.024) lower in CIN I (45%) than in more severe dysplastic (CIN II 70%, CIN III 80%) lesions. In contrast, no differences were seen in the enzymatic activity detected by the TRAP assay among the different dysplastic lesions. CONCLUSIONS: These data indicate that, using a molecular extra situ method, the telomerase activity of inflammatory and non-dysplastic elements masks the expected differences between mild and severe dysplasia. Conversely, an in situ approach permits the accurate identification of telomerase positive dysplastic cells.

Activatory effect of two cardioglycosides on Cavia cobaya kidney Na+/K+-ATPase activity.

Ouabain and K-strophanthoside promote an enhancement of Na+/K+-ATPase activity in a range of cardioglycoside concentrations from 100 nM to 100 pM, with a maximum (+30%) between 10 and 4 nM. Binding experiments with [3H]ouabain show upward-curved Scatchard plots and evidence two intrinsic affinity constants for the ligand: (a) High-affinity constant: 350 nM (microsomes) and 15 nM (purified enzyme). (b) Low-affinity constant: 2100 nM (microsomes) and 890 nM (purified enzyme). The reaction velocity trend indicates that at ouabain concentrations higher than 20 nM but lower than the minimal inhibiting level, the enhanced reaction velocity is tending towards the control values.

Na+/K+-ATPase from Xenopus laevis (Daudin) kidney and epidermis: high sensitivity towards regulatory compounds.

Na+/K+-ATPase was prepared from Xenopus laevis epidermis. Purification was obtained by ultracentrifugation on sucrose discontinuous gradient. The maximum of enzyme-containing membranes was concentrated in the denser sucrose layer, exhibiting a good and long-lasting activity (specific activity about 55 mumoles of ATP hydrolyzed/mg of protein/hour). The Kd for the ouabain of kidney and epidermis enzymes were very low (in purified preparations respectively 16 nM for kidney enzyme and 4 nM for skin enzyme), indicating a very high sensitivity toward the cardioglycoside. The dose-response graphs of kidney and skin Na+/K+-ATPase vs ouabain concentrations show that at ouabain concentrations ranging from 1 nM and 1 pM the inhibition elicited by the cardioglycoside disappears and is replaced by an activatory effect. At cardioglycoside concentrations higher than 1 nM, the graphs show the typical inhibition curve.

Sodium, and potassium dependent adenosinetriphosphatase from Cavia cobaya kidney: interaction with very low cardiotonic steroid concentrations.

We noticed that very low cardiotonic steroid concentrations activate the Na, K-ATPase in a variety of different preparations. In the present research the effect of three cardioactive steroids on the enzymatic activity was tested. The glycosides activated the Na,K-ATPase, while the aglycone strophantidine does not. Ouabain binding studies on various preparations showed the presence of two binding site classes with different affinities. Purification procedures shift the apparent Kd values, while K+ increase them. Accordingly, the activatory and inhibitory effects may be explained by the cardiotonic steroid binding on different sites of the Na,K-ATPase molecule.

Na,K-ATPase from Xenopus laevis kidney and epidermis: ouabain interaction studies.

A satisfactory purification from Xenopus laevis epidermis is presented. Ki and Kd values for the ouabain-enzyme interaction have been evaluated. Both parameters appear very low, as compared with those demonstrated in other anurans. Very low digitalis-like compound level was demonstrated in Xenopus; on the contrary in Bufo, in which these substances play a defensive role, it is very high. Our results strengthen the hypothesis of a physiological action of such compounds in regulating enzyme-driven Na+/K+ exchanges.