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Biomedical subjects

S Benvenuti

Publications and source records attributed to S Benvenuti.

At least 37 records · Page 2Linked to original sources
PubMed1999

Fluid shear stress increases interleukin-11 expression in human osteoblast-like cells: its role in osteoclast induction.

It is unclear how mechanical stress influences bone cells. Mechanical stress causes fluid shear stress (FSS) in the bone. Osteoblast lineage cells are thought to sense FSS and regulate bone remodeling. We therefore investigated the effects of FSS on human osteoblast-like osteosarcoma cells: SaOS-2 cells in vitro. The conditioned medium of the SaOS-2 cells after 24 h of FSS (24 h-FSS CM) showed such osteoclastic phenotype inductions as significantly increasing the number of tartrate-resistant acid phosphatase (TRAP) positive multinuclear cells in rat bone marrow cells and TRAP-positive cells in human preosteoclastic cells: FLG 29.1 cells. An enzyme-linked immunosorbent assay showed interleukin-11 (IL-11) protein to increase 7-fold in the 24 h-FSS CM. A Northern analysis showed that IL-11 mRNA increased 4-fold in the SaOS-2 cells after 6 h-FSS; however, no IL-6 mRNA expression was detected. Furthermore, the anti-human IL-11 antibody significantly neutralized the osteoclastic phenotype induction of the 24 h-FSS CM. The IL-11 mRNA up-regulation in SaOS-2 cells by the 6 h-FSS was not inhibited by the anti-human transforming growth factor-beta1 antibody, but it was significantly inhibited by indomethacin. An enzymeimmunoassay showed prostaglandin E2 to increase 7-fold in the 1 h-FSS CM. These findings thus suggest that FSS induces osteoblasts to produce IL-11 (mediated by prostaglandins) and thus stimulates bone remodeling.

Acid Phosphatase↗
PubMed1999

[Latex allergy. An not rare intraoperative event].

Latex allergy has become a real problem among both surgical staff (paramedics and physicians) and patients especially pediatric patients with urogenital malformations and spina bifida. Latex allergy is produced from both natural molecules which compose the substance produced from Hevea brasiliensis (rubber tree) and industrial additives contents in latex devices. Diagnosis of latex allergy may be carried out through a preoperative Prik-test. A characteristic of latex allergy reaction is the starting of symptoms (more than 15 minutes after allergen contact). Pathophysiology of latex allergy is the same of all allergic reactions; it is an antigen-antibody reaction and type I or II reaction may occur. There are a lot of devices that surgeons and anesthesists use in the operative theatre and that should not be used in presence of a patient with latex allergy. Guaranteed latex-free devices should always be present in store.

Humans↗
PubMed1997

Heterogeneity of binding sites and bioeffects of raloxifene on the human leukemic cell line FLG 29.1.

The benzothiophene divarative raloxifene is known to mimic estrogen in human bone remodeling. To investigate the "in vitro" properties of raloxifene on osteoclast precursors, the human leukemic cell line FLG 29.1, which differentiates toward the osteoclastic phenotype, was examined for raloxifene binding and for evidence of its bioeffects. Scatchard and Hill analysis of binding data with the tritiated raloxifene demonstrated the presence of two classes of binding sites in both nuclear and cytosol fractions with Kd values of approximately 1 nM and approximately 5 nM, respectively. In addition, analysis of binding data using tritiated 17 beta E2 as ligand at high concentrations (10-40 nM) and either unlabeled 17 beta E2 or raloxifene as competitors gave similar results demonstrating the presence of type II EBS in these cells. Picomolar concentrations of raloxifene significantly (p < 0.05) inhibited cell proliferation. Moreover, the compound at nanomolar concentrations induced a significant dose- and time-dependent increase of progesterone receptor, and activated apoptotic cell death. These findings clearly demonstrate that raloxifene acts as an estrogen agonist in FLG 29.1 cells, acting through the estrogen receptor and, possibly, via multiple cooperative binding component(s).

Apoptosis↗
PubMed1997

Insulin-like growth factor-I stimulates in vitro migration of preosteoclasts across bone endothelial cells.

Little is known about the factors and the mechanisms involved in preosteoclast emigration from the vasculature. In this study, an in vitro model of bone endothelial lining was mimicked by culturing bone endothelial (BBE) cells at confluence on a 3-microm pore polycarbonate membranes. Preosteoclastic (FLG 29.1) cells were then added on top of the BBE cell monolayer and 10 nM insulin-like growth factor-1 (IGF-I) was added below the supporting membrane. Scanning and transmission electron microscopy were used to evaluate the chemotactic responses of preosteoclastic FLG 29.1 cells towards the IGF-I generated gradient. IGF-I potently stimulated chemotaxis in the FLG 29.1 cells, as shown by the migration of the preosteoclastic cells across the underlying BBE and through the intercellular junctions between adjacent endothelial cells. Subsequently, FLG 29.1 cells penetrated the pores of the supporting membrane and reached the lower face of the membrane. Thus, IGF-I, which is abundantly present in the bone tissue microenvironment, may play a paracrine role in the recruitment of the circulating preosteoclasts from the vascular compartment into the bone tissue. This in vitro model, which mimicks the in vivo phenomenon of preosteoclast extravasation, should prove useful in elucidating the molecular mechanisms that underlie this process.

Adult↗
PubMed1997

Evaluation of the cost of home care for terminally ill cancer patients.

The aim of this work was to carry out a cost evaluation of the home care programme for terminally ill cancer patients run by the Istituto Oncologico Romagnolo (I.O.R.) in the areas of Forlì, Cesena, Ravenna and Rimini (Romagna, Italy). To determine effective home care direct costs, we first selected 1 week of care as an observation unit. We then proceeded to assess the medical and nursing care units together with the clinical protocols administered for each patient. The Karnofsky Performance Status (KPS) was also assessed weekly. In this way, we calculated care costs for each patient and for each week as the sum of medical costs, nursing costs, treatment costs and other costs. A consecutive series of 574 patients were involved in the study from 1 April 1994 to 31 March 1995. A total of 5164 patient-weeks of care was provided, with an average cost per week of 177.6 Ecu. This weekly cost increased in the last 100 days of life (week -15 = 179.5 Ecu; week -8 = 188.3 Ecu; week -2 = 221.0 Ecu; P < 0.001). When single components were analysed in relation to total cost (treatment protocols, physician and nursing care) the increased global cost was found to be mainly attributable to the intensification in nursing care (21.8% of costs in week -15 vs 27.3% of costs in week -2). Examination of the relation between the cost of 1 week of care and KPS values clearly shows that healthcare costs increased as KPS decreased (from 152.2 Ecu with KPS > or = 60 to 292.6 Ecu with KPS < or = 20; P < 0.001). Home care costs were also seen to vary with some clinical characteristics and symptoms present when patients entered the study: asthenia, anorexia, nausea/vomiting, bedsores. Given the good results of home care for cancer patients in terms of quality of life, this method of cost accounting for home-care providers can help to monitor the rising cost of assistance and confirm the cost effectiveness of this type of care.

Adolescent↗
PubMed1997

HPE cells: a clonal endothelial cell line established from human parathyroid tissue (human parathyroid cell line).

We report the culture and cloning of human endothelial cells derived from parathyroid tissue surgically removed from a patient affected by Multiple Endocrine Neoplasia Type 1 syndrome. These cells, known as HPE, have been isolated and maintained in culture by serial passages for more than 15 months. The clonal cell line grows in a medium containing serum substitutes which favour endothelial cell growth. HPE cells replicate with a mean doubling time of 120 h, showing typical functional and morphological features of endothelial cells, such as uptake of acetylated low density lipoprotein and positive reaction for Factor VIII-Related Antigen. Basic fibroblast growth factor, vascular endothelial growth factor, insulin-like growth factor type I and ascorbic acid stimulate cell proliferation, whereas transforming growth factor beta and heparin act as inhibitory factors. Prostaglandin E2, secretin and epinephrine increased cAMP production, while human parathyroid hormone, histamine and glucagon were inert. Cells were found to express pro-collagen alpha 1 (type I) mRNA. In HPE cells Restriction Fragments Length Polymorphism and PCR analysis did not show allelic loss at chromosome 11q12-13, known to be a typical feature of MEN 1 parathyroid tumors. These cells are the first example of an established normal human clonal cell line with an endothelial phenotype.

Cell Division↗
PubMed1997

Synthesis, antimicrobial and genotoxic properties of some benzoimidazole derivatives.

A number of 1H-benzoimidazol-2-ylamine and of 1-methyl-1H-benzoimidazol-2-ylamine derivatives were synthesized and the crystal and molecular structure of N-[4-(2-amino-benzoimidazole-1-sulfonyl)-phenyl] acetamide was determined by X-ray diffraction analysis. The compounds obtained were investigated for antimicrobial and genotoxic activities.

Anti-Infective Agents↗
PubMed1997

[The epidemiology of the gastroduodenal damage induced by aspirin and other nonsteroidal anti-inflammatory drugs].

A substantial body of studies (controlled, cohort and case-control studies) now confirm the long established impression that there is an increased prevalence of gastric and duodenal ulcer and of associated complications in subjects treated with aspirin (ASA) or with non-steroidal anti-inflammatory drugs (NSAIDs). The overall percentage of ulcers/erosions in patients treated with ASA ranges from 10 to 50% with a relative risk of bleeding ranging from 1.8 to 15%. The overall relative risk of ulcers/erosions in NSAIDs-treated subjects is around 3%, with complications detectable in 2.4% of cases. The risk of lesions and complications associated with ASA/NSAIDs is more marked in patients aged over 65, in those with a previous history of ulcer (both symptomatic and silent), in those treated with substantial doses or with combinations of NSAIDs and in those concomitantly using anticoagulants and/or steroids. The epidemiological data highlight the importance of implementing ASA/NSAIDs therapy only when strictly necessary as well as the advisability of adopting as broad a range of measures as possible to reduce the tissue-damaging effects of these pharmacological agents.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

[Accident during retinal fluorescein angiography].

OBJECTIVE: To evaluate adverse reactions frequency following fluorescein i.v. administration to perform retinoic angiography (ARF). DESIGN: Retrospective study. SETTING: Eye Clinic of the University of Florence. MATERIALS AND METHODS: 6524 patients undergoing 10,003 ARF. PARAMETERS EVALUATED: For each patient age, sex, concomitant diseases, previous ARF, allergic history and any adverse reaction were evaluated. RESULTS: Adverse experiences were described in 7.5% of 6524 patients. Most of the observed reactions were mild: nausea (3.8%), vomiting (0.43%), vasovagal phenomena (1.18%), anaphylactoid reactions (1.84%). A major rate of adverse reactions were observed in patients previously submitted to ARF who reported in the anamnesis a previous adverse reaction, and in those with a positive allergic history. Severe reactions occurred in 0.27% of patients, but only in 2 of 6524 patients a rianimatory treatment (0.03) was necessary. CONCLUSION: From the data retrospective analysis it was observed that the manifestation of mild adverse effects was to be expected in many cases. It was therefore possible to point out classes of patients at risk (patients who reported a previous adverse reaction after ARF and patients with positive allergic history). Unfortunately it was not possible to expect and so to prevent the severe effects. Thus it is recommended to perform ARF in an adequately equipped room.

Adolescent↗
PubMed1997

Bioeffects of a nitric oxide donor in a human preosteoclastic cell line.

Nitric oxide is a short-lived free radical produced by different isoforms of the enzyme nitric oxide synthase. It regulates a whole range of functions in the body, but little is known about its effects on bone. Rat osteoclasts and a human preosteoclast cell line (FLG 29.1) have been shown to produce nitric oxide and to express nitric oxide synthases. In the present study we investigated the role of a nitric oxide donor, 3-morpholinosydnonimine hydrochloride, on the FLG 29.1 cells. 3-Morpholinosydnonimine hydrochloride has been shown to significantly increase IL6 production and tartrate resistant acid phosphatase activity in FLG 29.1 cells, indicating a positive modulation of osteoclast differentiation. However FLG 29.1 cell adhesion on osteoblast-like cells was significantly inhibited, suggesting an inhibition of osteoclast motility. All these results confirm the bidirectional effect of nitric oxide whose basal production is necessary in promoting osteoclast differentiation, while at high levels it is effective in inhibiting osteoclast activity.

Acid Phosphatase↗
PubMed1997

Gastrectomy, lack of gastric first pass metabolism of ethanol and alcoholic liver disease. Results of a multicentre study.

BACKGROUND: Some conditions characterized by a loss (anatomical or functional) of parietal cells of the gastric antrum, containing an alcohol-dehydrogenase, may reduce the first pass metabolism of ethanol at that level and, simultaneously, raise its bioavailability. The observation that the first pass metabolism was drastically suppressed after gastrectomy would appear to suggest that the latter condition represents a risk for the development of liver damage in patients who continue to consume alcohol even in a non relevant amount. METHODS: Consecutively enrolled in the study were 304 individuals of both sexes aged between 45 and 70 years of whom 114 gastrectomized and 190 pair-matched control subjects all submitted to an Upper Gastrointestinal Endoscopy for whatever disturbance. All the patients were diagnosed as having liver disease with routine clinical and instrumental means. Information was collected concerning the mean daily alcohol intake, both before and after the operation. RESULTS: The overall prevalence of hepatic lesions was shown to be higher in the gastrectomized than in the control group (42.1% vs 25.8%, p = 0.005). Moreover, referring only to alcohol-related hepatic lesions (steatosis, steato-fibrosis and cirrhosis), the prevalence was higher in the gastrectomized patients than in the controls (29.8% vs 17.9%, p = 0.02). As far as concerns alcohol consumption, the gastrectomized group had consumed 71 g/day and the control group 39 g/day alcohol per person (p < 0.05) in a similar period of time (35 and 33 years, respectively). Also the non alcohol-related liver damage (especially the viral type) was slightly higher in the gastrectomized patients (gastrectomized 12.3% vs control 7.9%, p = ns). Accordingly, the percentage of serum markers of viral infection was higher in this group (HBs Ag: gastrectomized 3.9% vs control 2.2%, p = ns; anti-HCV: gastrectomized 13.5% vs control 5.0%, p = 0.03). Finally, to test the eventual damaging effects of gastrectomy alone (excluding ethanol and/or viral infection), two groups of patients with a medium to low alcoholic negative assumption (30-60 g ethanol/day) and no signs of viral infection (HBsAg and anti-HCV negative) were extrapolated. In these two selected groups, the prevalence of alcoholic-related hepatic lesions were not statistically different (28 gastrectomized 20.3% vs 44 control 18.4%). CONCLUSIONS: In conclusion, data emerging from investigations on the population under study indicate that the alcohol and viral infection appear to play a more important role in determining hepatic lesions than gastroresection.

Aged↗
PubMed1996

Olfaction and the homing ability of pigeons in the southeastern United States.

The importance of atmospheric odors for homing pigeon navigation was tested using birds from a loft located in Savannah, GA, in the southeastern United States. When released from a familiar training site, control pigeons and pigeons given intranasal injections of zinc sulfate to produce anosmia both displayed good homeward orientation and homed quickly. When released from three unfamiliar release sites, in contrast, control birds tended to orient southeast, while zinc sulfate-treated birds were more likely to fly northwest. More importantly, while the majority of control pigeons returned to the home loft, few of the zinc sulfate-treated birds returned. The good performance of both groups from the familiar site indicates that zinc sulfate treatment does not impair the general motor ability or motivation of homing pigeons. Therefore, the observed impairment in homing success of the zinc sulfate-treated pigeons from the unfamiliar locations presumably reflects an impaired ability to use atmospheric odors to navigate home. As such, the data support the hypothesis that successful homing pigeon navigation is based on the perception of atmospheric odors and that olfactory navigation is the primary mechanism used by pigeons over a broad range of geographic areas to approximate their relative position with respect to home from unfamiliar locations.

Animals↗
PubMed1996

Histamine receptors and bioeffects on clonal parathyroid endothelial cells.

Using a clonal line of bovine parathyroid endothelial cells (BPE-1) we defined the presence on these cells of a histamine H2 receptor and characterized its pharmacological properties. Interaction of histamine with its receptor induced an increase of cAMP accumulation in a dose- and time-dependent fashion. This effect appears unique for parathyroid endothelial cells, in fact, clonal parathyroid epithelial cells did not exhibit a similar response. No effect of histamine was observed on BPE-1 cell proliferation.

Animals↗
PubMed1996

Characterization and function of the receptor for IGF-I in human preosteoclastic cells.

Using a coculture system, we have recently demonstrated that insulin-like growth factor I (IGF-I) is a mediator of preosteoclastic cell migration toward bone-derived endothelial cells. To better characterize the mechanisms of IGF-I action on preosteoclastic cells we evaluated the expression of type I IGFs receptor in the human leukemic cell line, FLG 29.1, which differentiates toward the osteoclastic phenotype following phorbol ester (TPA) treatment. Scatchard analysis of 125I-labeled IGF-I to FLG 29.1 cells revealed the presence of a single high affinity binding site in both untreated and TPA-treated cells with a similar Kd value (0.3 +/- 0.2 nmol/L and 0.4 +/- 0.1 nmol/L, respectively). In untreated cells, IGF-I binding capacity (1.43 +/- 0.41 fmol/10(6) cells) was significantly (p < 0.05) lower than in TPA-treated cells (2.62 +/- 0.87 fmol/10(6) cells). Competition analyses and crosslinking studies revealed the presence of type I IGF receptor both in untreated and TPA-treated cells. Northern analysis demonstrated that mRNA for IGF-I receptor was expressed by both untreated and TPA-treated FLG 29.1 cells. In addition, FLG 29.1 cells released in the conditioned medium IGFBP-2 and IGFBP-4, whose expression was increased by TPA treatment as demonstrated by ligand and immunoblot analyses. The previous observations of chemotactic action of IGF-I on FLG 29.1 cells was confirmed by ultrastructural observations. Indeed, these cells revealed a marked migratory activity in response to nanomolar concentrations of IGF-I. In addition, the IGF-I receptor alpha IR-3 antiserum inhibited the IGF-I-induced FLG 29.1 cell's migratory activity. These findings clearly show that type IIGF receptor is expressed by osteoclast precursors and that IGF-I induces migration of these through the binding to type I IGF receptors. Binding proteins expressed by osteoclast precursors may play an autocrine role in modulating the IGF-I bioeffects.

Adult↗
PubMed1996

Membrane binding sites and non-genomic effects of estrogen in cultured human pre-osteoclastic cells.

Besides functional estrogen receptors, the presence of signalling cell surface binding sites for 17beta-estradiol (17betaE2) has been reported in osteoblast- and osteoclast-like cells, suggesting that 17betaE2 may influence bone remodelling by a dual mechanism of action: to affect gene expression mediated by the nuclear activity of the steroid-receptor complex, and to initiate rapid responses triggered by a signal-generating receptor on the cell surface. Recently, we demonstrated that the human pre-osteoclastic cell line FLG 29.1 bears functional estrogen receptors. In this study we examined FLG 29.1 cells for the presence of cell surface binding sites for 17betaE2, and whether 17betaE2 could elicit cell signalling. Using a cell-impermeant and fluorescent estrogen conjugate, 17beta-estradiol-6-carboxymethyloxime-bovine serum albumin-fluorescein isothiocyanate, we demonstrated the presence of specific plasma membrane binding sites for 17betaE2. Stimulation of FLG 29.1 cells with low (1 nM) and high (1 microM) doses of 17betaE2 induced a prompt and significant (P < 0.05) increase of cellular pH, as measured in single cells using an image analysis system. In addition, both cAMP and cGMP were significantly increased by 17betaE2 with a dose-dependent response. Finally, a rapid increase of intracellular calcium ion concentration [Ca2+] was also induced by 1 nM 17betaE2, as measured in single cells using an image analysis system. Our findings strongly suggest a non-genomic action of 17betaE2 on osteoclast precursors.

Calcium↗
PubMed1996

Homing behaviour of pigeons subjected to unilateral zinc sulphate treatment of their olfactory mucosa

Pigeons were made anosmic by unilateral treatment of their olfactory mucosa with a zinc sulphate solution and by plugging the contralateral nostril. In a series of releases at unfamiliar sites, 55&shy;79 km from the home loft, the experimental birds' homing behaviour was compared with that of two control groups: unmanipulated control birds, and birds subjected to unilateral zinc sulphate treatment and equipped with an ipsilateral nasal plug. The experimental pigeons exhibited homing behaviour &shy; in terms of both homeward initial orientation and homing performance &shy; significantly poorer than that of both unmanipulated and treated control pigeons. In addition, the homing behaviour of the treated controls turned out to be only slightly, and not significantly, poorer than that of the unmanipulated birds. The results show that the impaired homing capabilities of the zinc-sulphate-treated birds are due to the lack of navigational information and not to non-specific brain damage caused by the experimental treatment.

Journal Article↗
PubMed1996

[Diet and drugs in the therapy of nonorganic dyspepsia: the hypothesis and factual data].

Non-organic dyspepsia, although not frequently reported, is still a disorder which is difficult to classify in nosographic and physiopathological terms, a fact which inevitably influences the indications for its treatment. Non-pharmacological treatment of non-organic dyspepsia includes changes in dietary and behavioural habits which, even if established on empirical grounds, play a far from ancillary role. When considered appropriate, pharmacological treatment must be formulated solely on the basis of controlled clinical trials vs placebo given the well-known significance of the placebo effect in this and other so-called "functional" diseases. The therapeutic strategies which are most subject to verification are based on the one hand on the neutralisation or inhibition of gastric acid secretion and, on the other, on the improvement of gastrointestinal motility. Surprisingly, the widely used antacid drugs are among those which have been less well studied and show the lowest efficacy. Among the anti-secretory drugs, pirenzepine is approximately 25% more effective than placebo. H2-antagonists, the drugs which have been most closely studied both in terms of the number of trials and the size of the sample populations studied, produce contradictory results. However, a meta-analysis of the trials shows an overall 18% improvement in efficacy compared to placebo. The overall results of studies on prokinetic compounds are "good" in meta-analytical terms, with an improved efficacy of 50% compared to placebo. This is not necessarily due to the superiority of prokinetic compared to anti-secretory drugs and can be explained by the reduced placebo effect in trials using prokinetic drugs or a greater presence in the latter of dyspepsia which is physiopathologically correlated to motor discord. Among the future drugs still being studied, it is particularly worth mentioning fedotozine, a specific K opioid receptor agonist which appears to have provided extremely interesting results in preliminary studies. The role of barrier drugs, such as sucralfate and colloidal bismuth, continues to remain unclear and in particular the latter might be of increased use if evidence of a relationship between Helicobacter pylori and non-organic dyspepsia were reinforced; this relationship may in fact not exist in all dyspeptic patients but only in a subgroup. Lastly, the problem of the duration of pharmacological treatment still remains unsolved, as do the questions of whether longterm treatment should be conceived once acute symptoms have disappeared and whether it is possible to hypothesise differentiated pharmacological treatment depending on the clinical variants of functional dyspepsia which have been defined with greater attention over the course of the past decade.

Combined Modality Therapy↗