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Biomedical subjects

N Giordano

Publications and source records attributed to N Giordano.

At least 19 recordsLinked to original sources

Fluid flow through nanometer-scale channels.

We describe studies of the pressure driven flow of several classical fluids through lithographically produced channels in which one dimension, the channel height h, is in the micron or nanometer size range. The measured flow rates are compared with theoretical predictions assuming no-slip boundary conditions at the walls of the channel. The results for water agree well with this prediction for h as small as 40 nm (our smallest channels). However, for hexane, decane, hexadecane, and silicone oil we find deviations from this theory when h is reduced below about 100 nm. The observed flow rates for small h are larger than theoretical expectations, implying significant slip at the walls, and values of the slip length are estimated. The results are compared with previous experimental and theoretical work.

Journal Article↗

Infection by CagA-positive Helicobacter pylori strains in patients with ischemic heart disease: prevalence and association with exercise-induced electrocardiographic abnormalities.

The role of H. pylori infection in increasing the risk of ischemic heart diseases (IHD) is still debated. We determined serologically the prevalence of overall H. pylori and CagA-positive H. pylori infection in 63 consecutive patients with IHD and 189 gender- and age-matched controls. We also determined in patients the influence of the infection and the CagA serological status on the results of an exercise ECG test and other parameters considered possible variables that may enhance the risk of IHD. The prevalence of H. pylori infection in patients and controls was 79.3% and 73.0%, respectively (P = 0.403) and that of CagA-positive H. pylori infection was 69.8% and 42.3%, respectively (P = 0.0002). The scores of the ECG S-T segment and T-wave abnormalities in the course of an exercise ECG in uninfected patients and in patients infected by CagA-negative and CagA-positive H. pylori strains were (mean +/- SD): 1.59 +/- 0.67, 1.92 +/- 0.64, and 2.19 +/- 0.70, respectively; (P = 0.011, 95% confidence limits of difference 0.15-1.07, CagA-positive infected vs uninfected patients). There was no intergroup difference in the levels of peripheral white blood cells, glucose, cholesterol, triglycerides, creatinine, and systolic and diastolic pressure. In conclusion, genetic heterogeneity of H. pylori could possibly explain some conflicting results concerning the association of H. pylori infection with IHD. Coronary vessels of IHD patients infected by CagA-positive H. pylori strains may be damaged more severely than those of uninfected patients.

Adult↗

Acute hepatitis induced by cyproterone acetate.

OBJECTIVE: To report a case of acute hepatitis resulting from the use of cyproterone acetate, an adjuvant treatment for prostate cancer. CASE SUMMARY: An 87 year-old white man, admitted to surgery for prostate cancer, received cyproterone acetate 300 mg/d orally and developed acute hepatitis, which initially was diagnosed clinically. A liver biopsy showed changes suggestive of acute cholestatic hepatitis. Cyprotorone was stopped immediately, and the patient was subsequently treated with corticosteroids. He then improved rapidly. DISCUSSION: Cyproterone acetate is thought to be well tolerated, but some authors have reported severe hepatic reactions, in particular acute hepatitis, fatal fulminant hepatic failure, and hepatocellular carcinoma. The above-mentioned hepatotoxicity represents an idiosyncratic drug reaction, probably due to the hepatomitogen action of cyproterone, causing an increase of hepatocytes expressing placental glutathione S-transferase, which are considered preneoplastic elements. CONCLUSION: This case suggests the possibility of hepatotoxicity from cyproterone.

Adenocarcinoma↗

Piano hammers and their force compression characteristics: does a power law make sense?

We have studied the force characteristics of a collection of piano hammers, through studies of the acceleration of the hammer head, the force due to the compression of the hammer felt, Fh, and the associated bending of the hammer shank which occurs when a hammer strikes a rigid object. By integration of the acceleration one can estimate the compression of the felt, and thus obtain a force-compression Fh(z) relationship; our results for this function are compared with previous experiments and theoretical models. Close examination of our findings suggests that bending of the hammer shank, and also the time required for the force to be transmitted from the outer edge of the hammer to its core, play significant roles in the hammer dynamics. The data are used to estimate the quantitative impact of these effects on the derived Fh(z) relation. The implications for physical modeling of a piano tone are briefly discussed.

Journal Article↗

[Molecular genetics and bone diseases].

The authors describe the molecular mechanisms determining some skeletal diseases, in particular those due to a well-defined, single genic defect. In fact, they examine the hereditary disorders due to mutations in the genes encoding the different collagen types and the hereditary diseases secondary to the defects in: a) the structural proteins of cartilage; b) the enzymes and the sulfate transporters of proteoglycans; c) the transcription factors; d) the growth factors. At the end, the authors emphasize the importance of the genetic studies on animal models, for understanding the etiopathogenesis of many human hereditary disorders.

Bone Density↗

[Usefulness of online bibliographic research in biomedical research, with an application to the epidemiologic study of genetic osteopathy].

The bibliographic research online is an useful means of recovering information in all the subjects, particularly in the field of biomedicine. In fact, this instrument allows researchers to get information in a rapid, complete and up-to-date way. The aim of the present review is to describe the usefulness of the bibliographical research online in the field of the genetic osteopathies. These are rare disorders: so, their own rarity makes the bibliographical research online necessary to carry out a large and effective comparison of experiences. The obtained results are amply reported in the manuscript. For instance, we verified that chondrodysplasias are the diseases most represented in the literature, while melorheostosis the disorder less mentioned. Moreover, we evidenced that some hereditary disorders of connective tissue, such as Marfan's syndrome, osteogenesis imperfecta and Ehlers-Danlos syndrome, are strongly influenced by race, sex and age.

Bibliometrics↗

Weill-Marchesani syndrome: report of an unusual case.

We report a single case of Weill-Marchesani syndrome, typically characterized by progressive joint stiffness, brachiymorphy, brachydactyly, and ectopia lentis. The clinical case appears particularly interesting as the patient also had primary osteoporosis, which until now has not been considered as a possible manifestation of Weill-Marchesani syndrome.

Adult↗

Paget's disease.

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Alleles↗

Reactive arthritis by staphylococcus epidermidis: report of an unusual case.

In the literature many cases of Staphylococcus epidermidis (SE) complications are reported, but we have not found any reference about reactive arthritis secondary to SE. We report an unusual case of a patient with SE bacteriaemia, who developed elbow arthritis, asymmetrical sacroiliitis, keratoderma and restrictive cardiomyopathy. The clinical pictures, the instrumental and biochemical findings, in particular the positivity of HLA B27, allow us to set this case in the complex and heterogeneous chapter of reactive arthritis.

Adult↗

[Not Available].

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Female↗