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Biomedical subjects

C Natale

Publications and source records attributed to C Natale.

At least 19 recordsLinked to original sources
PubMed2004

Self-assembled monolayers of organosulphur molecules bearing calix[4]arene moieties.

We investigate the self-assembly of modified calix[4]arene on gold surfaces. Calix[4]arene was modified through a reaction sequence which led to assembling of the crown-5 moiety and to the insertion of two thioether groups into the starting molecule. The so-obtained calix[4]arene-crown-5 bis(7-thiatridecyloxy) (hereafter called calix[4]arene) was in the stable 1,3-alternate conformation. The calix[4]arene/gold interface was investigated by means of spectroscopic ellipsometry (SE), scanning tunneling microscopy (STM) and cyclic voltammetry (CV). SE data indicate a layer thickness compatible with the formation of a monomolecular layer. This result is confirmed by STM imaging which shows the formation of a high density of small pits, one gold layer deep, a typical feature of self-assembled organosulphur monolayers on gold. CV measurements performed in presence of the [Ru(NH(3))(6)(2+/3+)] redox couple indicate a passivation of the metal electrode, resulting in a reduction of the redox current, after the layer deposition. CV has also been used to investigate the selectivity properties of calix[4]arene-covered gold electrodes by measuring the redox current decrease in the presence of different salt solutions. It is found that calix[4]arene-covered electrodes are able to complex K(+) and Ba(2+), while no complexation is observed in the case of Li(+), Na(+), Cs(+), Mg(2+) and Ca(2+).

Adsorption↗
PubMed2004

Intrabiliary rupture of a hydatid liver cyst: a case report.

Intrabiliary rupture of a hydatid liver cyst is a rare occurrence which may result in the development of obstructive jaundice and cholangitis. In this report we discuss the diagnostic and therapeutic management of a patient in whom the parasitic nature of cholangitis was underestimated due to the small size and site of the cyst, and to the misleading concomitant presence of cholelithiasis.

Cholangiography↗
PubMed2001

Octreotide 24-h prophylaxis in patients at high risk for post-ERCP pancreatitis: results of a multicenter, randomized, controlled trial.

BACKGROUND: Pharmacological prophylaxis of post-ERCP pancreatitis is costly and not useful in most non-selected patients, in whom the incidence of pancreatitis is 5% or less. However, it could be useful and probably cost-effective, in patients at high risk for this complication, where the post-procedure pancreatitis rate is 10% and more. AIM: To assess the efficacy of octreotide in reducing the incidence and severity of post-ERCP pancreatitis and procedure-related hospital stay, in subjects with known patient-related risk factors. METHODS: A total of 120 patients were randomly allocated to receive octreotide or not, in a multicentre, randomized, controlled trial. The drug was given subcutaneously, 200 microg t.d.s., starting 24 h before the ERCP procedure, in patients with either sphincter of Oddi dysfunction, or a history of relapsing pancreatitis or post-ERCP pancreatitis, or who were aged under 35 years, or who had a small common bile duct diameter (< 8 mm). RESULTS: A total of 114 patients (58 in the octreotide group and 56 in the control group) completed the trial. Post-procedure pancreatitis occurred in seven octreotide-treated patients (12.0%) and eight controls (14.3%). The two groups showed no significant differences in the incidence or severity of pancreatitis. Twenty-four hours after the procedure, severe hyperamylasemia (more than five times the upper normal limit) without pancreatic-like pain was recorded in three octreotide-treated patients (5.2%) and six controls (10.7%), the difference being not significant. CONCLUSION: Twenty-four-hour prophylaxis with octreotide proved ineffective in preventing post-ERCP pancreatitis and in avoiding 24-h severe hyperamylasemia in high-risk patients.

Adult↗
PubMed2000

Computer-assisted analysis of molecular mimicry between human papillomavirus 16 E7 oncoprotein and human protein sequences.

The immunology of human papillomavirus (HPV) infections has peculiar characteristics. The long latency for cervical cancer development after primary viral infection suggests mechanisms that may aid the virus in avoiding the host immunosurveillance and establishing persistent infections. In order to understand whether molecular mimicry phenomena might explain the ability of HPV to avoid a protective immune response by the host cell, sequence similarity between HPV16 E7 oncoprotein and human self-proteins was examined by computer-assisted analysis. Data were obtained showing that the HPV16 E7 protein has high and widespread similarity to several human proteins involved in a number of critical regulatory processes. In addition, multiple identical and different E7 peptide motifs are present in the same human protein. Thus, sharing of common motifs between viral oncoproteins and molecules of normal cells may be one cause underlying the scarce immunogenicity of HPV infections. The hypothesis is advanced that synthetic peptides harbouring viral motifs not and/or scarcely represented in the host's cellular proteins may represent a valuable immunotherapeutic approach for cervical cancer treatment.

Amino Acid Motifs↗
PubMed1999

[Laparoscopic cholecystectomy: evaluation of some postoperative instrumental parameters].

The Authors report a perspective study about 30 consecutive patients operated on for laparoscopic cholecistectomy to investigate the causes of some postoperative symptoms: the scapular ache, the persistent ache to the right side and the slight fever. Besides report the results of abdomen radiography and abdomen echography. The persistence of a moderate pneumoperitoneum not seem responsible for scapular ache; the absence of fluid under hepatic stuff not adduce good reason for right side ache and slight fever.

Adult↗
PubMed1999

In vitro survival of Listeria monocytogenes in human amniotic fluid.

A Listeria monocytogenes strain (CA01/93), haemolytic and virulent in mice, was inoculated in 16 samples of sterile human amniotic fluid to study the growth curves and to provide more information about the pathophysiology of the microorganism in pregnancy. A control test for every analysis was performed with an Escherichia coli strain (CN 02/95). Regardless of the amniotic fluid samples were taken at 34th-39th week of gestation, when it expresses maximum ability to inhibit growth of E. coli, the growth curves of L. monocytogenes do not show any bactericidal (only bacteriostatic) activity of the amniotic fluids against the tested strain. This gives an interesting result about the pathogenesis of the infection in pregnancy and about the potential environmental contamination due to long surviving times of the microorganism in-amniotic fluid.

Amniotic Fluid↗
PubMed1998

[Digestive anastomosis in general surgery].

Still today the digestive anastomoses are a subject very discuss and controversial in relation to the better technique. In fact the introduction of mechanical suture has placed the problem between this instrumentation and the classic technique. The Authors, comparing these two techniques, observe the peculiar aspects of each one and relate on the progresses, in last years, whether of the mechanical suture, with the improvement of the handy and the resistance of the anastomosis, or the threads of suture, ever more inert and resistant. Subsequently, the Authors relate your experience showing the form of realization of the anastomoses in the esophagogastric surgery, small intestine, colon-rectum, hepato-biliary and pancreatic surgery. In particularly, about the hand-sewn anastomosis, the Authors relate personal technique of reconstruction with extramucosal continuous suture, one-layer, with synthetic slow absorbable one-filament (PDS). In conclusion, the Authors declare that the introduction of the mechanical suture has certainly influenced the development of the new therapeutic solutions and has allowed intestinal anastomosis in sites of difficult access (abdominal esophagus, low rectum), but they think that the surgeon must to learn to know when is useless or neoplastic mechanical suture and he can realize manually the same anastomosis with quickness and safety.

Anastomosis, Surgical↗
PubMed1997

Enhanced expression of initiator TRNA(Met) in human gastric and colorectal carcinoma.

Transfer RNA isoaccepting species are differentially expressed at different times during development, differentiation, growth, aging, and carcinogenesis processes. It has been suggested that alterations in tRNA patterns might be mechanistically important in modulating gene expression during the various physiological/pathological cellular stages. As part of a study to investigate the possible mechanisms by which alterations of translational machinery can start and/or sustain carcinogenic cell proliferation, in this communication we report analysis of tRNA distribution in two gastro-intestinal human tumors. The qualitative and quantitative data obtained for cellular tRNA distribution put into evidence a shift in the tRNA population with increased level of initiator tRNA(Met) in the malignant tissues. This observation confirms previous data obtained on experimental carcinogenesis models and suggests the possibility of specific involvement of tRNA changes in protein synthesis initiation during tumorigenesis.

Chromatography, High Pressure Liquid↗
PubMed1992

Melanocytic neoplasia of the sole: diagnosis and therapeutic approach.

We examined retrospectively a series of 184 cases of melanocytic neoplasia of the sole observed and treated as out-patients from January 1977 to December 1987, comparing clinical and histological diagnoses. The original clinical diagnoses were divided into nevi, pigmented lesions of suspected malignancy, cutaneous melanomas and others. Of the 170 cases diagnosed clinically as nevus none was of melanoma. The risk that a pigmented skin lesion diagnosed as clinically benign is melanoma is so low as not to constitute a clinical problem. It is concluded that systematic removal of sole nevi is unjustified. If, however, there is the smallest doubt concerning a sole lesion, it should be removed and examined histologically.

Adolescent↗