PubMed Health⌕ Search

Biomedical subjects

R Bernardi

Publications and source records attributed to R Bernardi.

At least 19 recordsLinked to original sources
PubMed2006

[Metabolic syndrome and hypertension: prevention and treatment].

Since the 1950s the definition of the aggregate of metabolic disorders possibly presenting with adult obesity has evolved without reaching a unifying agreement on what metabolic syndrome is. After years of consensus on and research into identifying the extent to which certain criteria of metabolic syndrome may be predisposing factors for cardiovascular events, a reverse shift can be noticed in recent studies raising numerous points of contention about various elements that may be diagnostic for the syndrome. Of these, one of the most tenuous is probably arterial hypertension. Uncertainties have emerged regarding the arbitrariness of cut-off values, which differ according to the classification system the study applied, the methods of measurement, and the dilemma of hyperinsulinemia/insulin resistance which is present in only 50-60% of individuals with hypertension. Currently available data fail to solve these conundrums; however, some studies have correlated hypertension and dislipidemia with an increased risk of cardiovascular events. International epidemiologic data indicate that the prevalence of the syndrome varies between populations and between the sexes within the same populations, suggesting that diagnostic criteria need to take better account of ethnic group origin. Prevention of metabolic syndrome is still based on lifestyle changes; the huge risk of an imminent pandemic has called the attention of the American Heart Association to the importance of prevention and early treatment of the pediatric population--a new segment at risk of early cardiovascular events. Pharmacological therapy is directed at controlling various risk factors, particularly hypertension and metabolic disturbances. ACE inhibitors, sartans and statins are currently the drugs of first choice in treating metabolic syndrome.

Humans↗
PubMed2004

Effects of Siberian ginseng (Eleutherococcus senticosus maxim.) on elderly quality of life: a randomized clinical trial.

An unspecific feeling of fatigue and asthenia often pushes elderly patients to require any form of help even from non medically trained people. Traditional Chinese medicine suggest that Siberian ginseng could act as safe "adaptogenic" substance. Our aim was thus to test the effect of a middle term Eleutherococcus senticosus Maxim. (Araliaceae) administration on elderly, health related quality of life (HRQOL). 20 elderly hypertensive and digitalized volunteers (age >/= 65 years) were randomized in a double -blind manner to E. senticosus dry extract 300 mg/day (n = 10) or placebo (n = 10) for 8 weeks. The short form-36 health survey version 2 (SF-36v2), a validated general health status questionnaire, was used to access HRQOL at baseline and at 4 and 8 weeks. There were no significant differences in baseline demographics and SF-36v2 scores between the groups. At each visit, controls of digitalemia and blood pressure level were carried out. After 4 weeks of therapy, higher scores in social functioning (p = 0.02) scales were observed in patients randomized to E. senticosus; these differences did not persist to the 8-week time point. No adverse event has been observed in both groups of patients. No significant difference in both blood pressure control and digitalemia was observed in both treatment groups. Subjects give E. senticosus (70%) were more likely to state that they received active therapy than subjects given placebo (20%; p < 0.05). In conclusion, E. senticosus safely improves some aspects of mental health and social functioning after 4 weeks of therapy, although these differences attenuate with continued use.

Aged↗
PubMed2002

Effect of pilocarpine mouthwash on salivary flow.

Pilocarpine is a cholinergic agonist that increases salivary flow and has been used to treat xerostomia. Oral intake is the most frequent route of administration. Adverse effects are dose-dependent and include sudoresis, facial blushing and increased urinary frequency. The objective of the present study was to evaluate the effects of topical pilocarpine solutions as mouthwashes on salivary flow and their adverse effects on healthy subjects. Forty volunteers received 10 ml 0.5, 1 and 2% pilocarpine solutions or 0.9% saline in a randomized, double-blind, placebo-controlled manner. Salivation was measured before and 45, 60 and 75 min after mouth rinsing for 1 min with 10 ml of saline or pilocarpine solutions. Vital signs were measured and ocular, gastrointestinal and cardiovascular symptoms, anxiety and flushing were estimated using visual analog scales. There was a dose-dependent increase in salivation. Salivation measured after 1 and 2% pilocarpine (1.4 +/- 0.36 and 2.22 +/- 0.42 g, respectively) was significantly (P<0.001) higher than before (0.70 +/- 0.15 and 0.64 +/- 0.1 g), with a plateau between 45 and 75 min. Cardiovascular, visual, gastrointestinal and behavioral symptoms and signs were not changed by topical pilocarpine. Mouth rinsing with pilocarpine solutions at concentrations of 1 to 2% induced a significant objective and subjective dose-dependent increase in salivary flow, similar to the results reported by others studying the effect of oral 5 mg pilocarpine. The present study revealed the efficacy of pilocarpine mouthwash solutions in increasing salivary flow in healthy volunteers, with no adverse effects. Additional studies on patients with xerostomia are needed.

Adolescent↗
PubMed2001

Preparation and biological activity of four epiprogoitrin myrosinase-derived products.

(5R)-5-Vinyl-1,3-oxazolidine-2-thione, (2S)-1-cyano-2-hydroxy-3-butene, and two diastereoisomeric erythro-(2S)- and threo-(2S)-1-cyano-2-hydroxy-3,4-epithiobutanes were prepared in pure form starting from (2S)-2-hydroxybut-3-enyl glucosinolate (epiprogoitrin). This glucosinolate was isolated in almost pure form using ripe seeds of Crambe abyssinica and then hydrolyzed under different conditions. The hydrolysis was carried out using either myrosinase immobilized on nylon, to produce (5R)-5-vinyl-1,3-oxazolidine-2-thione, or the endogenous myrosinase contained in defatted crambe meals, to produce the other epiprogoitrin-derived products. After purification and physicochemical characterization, all four myrosinase degradation products were tested for their biological activity. A bioassay on Lactuca sativa was chosen as a simple test to determine their apparent action on living tissues. (5R)-5-Vinyl-1,3-oxazolidine-2-thione negatively affected mainly root growth, whereas (2S)-1-cyano-2-hydroxy-3-butene affected the early phase of germination, and both (2S)-1-cyano-2-hydroxy-3,4-epithiobutane diastereoisomers appeared to negatively affect both germination and root growth at doses 5-10 times lower than those of (2S)-1-cyano-2-hydroxy-3-butene or (5R)-5-vinyl-1,3-oxazolidine-2-thione.

Brassicaceae↗
PubMed2000

Cdc25A stability is controlled by the ubiquitin-proteasome pathway during cell cycle progression and terminal differentiation.

Members of the cdc25 family are protein phosphatases that play pivotal roles in cell cycle progression. Cdc25A has been shown to be a critical regulator of the G1/S transition of mammalian cells and to be a myc-target gene with oncongenic properties. We investigated the regulation of cdc25A during terminal differentiation using myeloblastic leukemia M1 cells, that can be induced to undergo differentiation into macrophages by interleukin-6 (IL-6) treatment. In this report it is shown that cdc25A protein is degraded by the ubiquitin-proteasome machinery in both terminally differentiating and cycling cells. Cdc25A was found to have two major peaks of accumulation during cell cycle progression, one in G1 and the other in S/G2. Evidence was obtained that degradation of cdc25A by the ubiquitin-proteasome machinery in terminally differentiating myeloid cells is accelerated compared to cycling cells. Moreover, deregulated expression of c-myc in M1 cells, which had been previously shown to block terminal differentiation, was also found to block IL-6 induced degradation of cdc25A.

Cell Cycle↗
PubMed2000

Isolation of the epithiospecifier protein from oil-rape (Brassica napus ssp. oleifera) seed and its characterization.

The epithiospecifier protein (ESP) is a myrosinase (MYR) cofactor, which is necessary to drive the MYR-catalyzed hydrolysis of some specific glucosinolates towards the production of cyanoepithioalkanes instead of isothiocyanates and nitriles. ESP was isolated from Brassica napus seeds by anionic exchange and gel filtration chromatography. ESP showed a molecular weight of about 39 kDa and pI 5.3. The amino acid sequence of several tryptic peptides of ESP (accounting for about 50% of the total sequence) made it possible to establish the high similarity (81% identity) with a hypothetical 37 kDa protein (TrEMBL data base accession number Q39104) and several jasmonate-inducible proteins from Arabidopsis thaliana. This observation suggests that ESP is likely to be involved in jasmonate-mediated defence and disease resistance mechanisms.

Amino Acid Sequence↗
PubMed1999

Formation of glucoraphanin by chemoselective oxidation of natural glucoerucin: a chemoenzymatic route to sulforaphane.

A new semi-synthetic way to produce glucoraphanin (2), the bio-precursor of the potential anticarcinogen sulforaphane (3), has been developed. Starting from glucoerucin (1), isolated from ripe seeds of Eruca sativa, glucoraphanin was obtained through chemoselective oxidation. Controlled myrosinase-catalysed hydrolysis of this precursor quantitatively afforded sulforaphane.

Catalysis↗
PubMed1999

Apoptosis-prone phenotype of human colon carcinoma cells with a high level amplification of the c-myc gene.

Although apoptosis can be induced by the enforced expression of exogenously introduced c-myc genes, it is not clear whether overexpression resulting from the amplification of the resident c-myc gene in tumor cells is sufficient to induce apoptosis. We have investigated the relationship between c-myc gene amplification and the propensity of tumor cells to undergo apoptosis, using the SW613-12A1 and SW613-B3 cell lines, which are representatives, respectively, of tumorigenic and non-tumorigenic clones isolated from the SW613-S human colon carcinoma cell line. Tumorigenic clones are characterized by a high level of amplification and expression of the c-myc gene, whereas cells of non-tumorigenic clones have a small number of copies and a lower level of expression of this gene. Analysis of c-myc mRNA level in cells cultured under low serum conditions indicated that the expression of the gene is tightly regulated by serum growth factors in non-tumorigenic B3 cells, whereas it is poorly regulated in tumorigenic 12A1 cells, the level of mRNAs remaining relatively high in serum-starved 12A1 cells. Under these conditions, 12A1 cells showed clear evidence of apoptosis, whereas B3 cells were completely refractory to the induction of apoptosis. Moreover, the study of cell lines derived from non-tumorigenic apoptosis-resistant clones following the introduction by transfection of exogenous c-myc gene copies showed that they have acquired an apoptosisprone phenotype. Altogether, our results strongly suggest that deregulated c-myc expression due to high-level amplification confers an apoptosis-prone phenotype to tumor cells. The possible consequences of these observations for cancer therapy are discussed.

Clone Cells↗
PubMed1997

Multiparametric staining to identify apoptotic human cells.

To analyze relevant features of HeLa and HL60 cells driven into apoptosis by etoposide, we have developed a new "tricolor" assay, based on the simultaneous analysis in the single cell of chromatin condensation, DNA degradation, and cellular poly(ADP-ribose) synthesis. The latter reaction is catalyzed by poly(ADP-ribose)-polymerase (E.C. 2.4.2.30), an enzyme which is activated by the presence of DNA free ends. The protocol consists in the visualization of apoptotic cells by Hoechst staining, TUNEL assay, and immunoreaction with anti-poly(ADP-ribose) antibody. We thus provide the first evidence that endogenous poly(ADP-ribose) production is indeed stimulated in cells undergoing apoptosis after treatment with antitumoral drugs, and that the monitoring of this endogenous enzymatic reaction, combined with morphological and other biochemical parameters, should facilitate the detection of apoptotic cells.

Adenosine Diphosphate Ribose↗
PubMed1997

Analysis of poly(ADP-ribose) glycohydrolase activity in nuclear extracts from mammalian cells.

We have analysed poly(ADP-ribose) glycohydrolase, the enzyme responsible for in vivo degradation of ADP-ribose polymers, by means of a biochemical assay based on the capacity of the enzyme to use a synthetic 32P-labelled polymer as a substrate. The visualization of the reaction has been achieved by separation of poly and mono(ADP-ribose) by thin-layer chromatography followed by autoradiography, whereas polymer hydrolysis has been quantified by counting the spots corresponding to poly and mono(ADP-ribose). By addition of the enzyme inhibitor ethacridine to the reaction mixture, we have confirmed the specificity of the procedure we have developed. The protocol has been applied to study the specific activity of glycohydrolase in nuclear extracts from different mammalian cell lines and to an apoptotic experimental system, namely HL60 cells treated with etoposide. We have observed the activation of the enzyme after a two-hour drug treatment, that is concomitant with the activation of poly(ADP-ribose) polymerase, the enzyme which synthesizes the polymer. These data suggest a precise regulation of ADP-ribosylation process during cell death by apoptosis.

Adenosine Diphosphate Ribose↗
PubMed1996

Sequence of events leading to apoptosis in long term cultured HeLa cells.

We have maintained HeLa cells in culture in the original medium for increasing times to induce growth arrest. Cell viability was evaluated by trypan blue dye exclusion assay. We observed that when cells are maintained in culture for several days, morphological hallmarks of apoptosis become evident. DNA synthesis rate, followed by (3)H-thymidine incorporation slowed down in long term cultured cells. This evidence was supported by the analysis of cell cycle progression determined by proliferating cell nuclear antigen (PCNA) immunostaining. Apoptotic cells have been characterized with respect to the sequential appearance of high molecular weight and internucleosomal DNA fragmentation. We have provided evidence that in this experimental model the first step in DNA degradation is represented by the formation of high molecular weight fragments, whereas nucleosomal DNA ladder is visible later on. The activation of the enzyme poly(ADP-ribose)polymerase, considered a marker of apoptotic death, has been observed. The results suggest that long term culture conditions activate the apoptotic programme.

Journal Article↗
PubMed1995

Syringomyelia after removal of benign spinal extramedullary neoplasms.

STUDY DESIGN: This is a case report. OBJECTIVES: Two patients with noncommunicating syringomyelia manifesting symptoms years after the uneventful excision of a benign intradural extramedullary neoplasms are presented. SUMMARY OF BACKGROUND DATA: The association of noncommunicating syringomyelia with benign extramedullary neoplasms as a coexistent or delayed process is a rare event. The pathogenesis of such spinal cord cavitation after tumor removal and the relationship with therapeutic intervention is not well defined. METHODS: The delayed occurrence of neurologic impairment emphasizes the need for considering development of syringomyelia rather than tumor recurrence. RESULTS: The effects of chronic spinal cord compression in the thoracic region may be accelerated by adverse stresses acting on the spinal cord associated with tethering of the spinal cord. CONCLUSION: In defining the pathogenesis of this form of spinal cord cavitation, these cases suggest that therapeutic approaches directed at resolving the process should not only include lyses of adhesions, but shunting procedures, which appear to be most efficacious when these procedures are performed at or cephalad to the level of original tumor removal.

Aged↗
PubMed1995

Induction of apoptotic cell death by DNA topoisomerase II inhibitors.

We have analyzed the interference of antitumoral drugs acting through the inhibition of DNA topoisomerase II on the human HeLa cell metabolism. Different compounds characterized by a diverse mechanism of action have been used, namely m-amsacrine, an intercalative drug, etoposide, which does not intercalate DNA, and suramin, which exerts its effect through an unknown mechanism. In HeLa cells treated with increasing doses of these drugs, we have examined cell viability and DNA synthesis capacity, and we have evaluated topoisomerase II activity. Cellular morphology and DNA integrity have been studied in order to characterize the mechanism of cell death. The results we have obtained clearly indicate that topoisomerase II poisons induce cell death by apoptosis. These observations suggest a role of the inhibition of topoisomerase II activity in the apoptotic program.

Amsacrine↗
PubMed1995

Activation of poly(ADP-ribose)polymerase in apoptotic human cells.

We have studied the effect of the chemotherapeutic drug VP-16 (etoposide) on the metabolism of HeLa cells by analysing different cellular parameters considered as markers of apoptosis. Typical features such as chromatin condensation and internucleosomal DNA cleavage are visible in HeLa cells exposed to VP-16. We investigated whether the appearance of small-sized DNA fragments could regulate the ADP-ribosylation process. To this purpose, we have analysed, by means of the activity gel technique; the structural and catalytical properties of poly(ADP-ribose)polymerase. In extracts from cells where etoposide-induced DNA fragmentation occurred, we have shown that the label of the autoribosylated form of the enzyme is greatly increased even if the amount of the protein remains constant. This phenomenon is completely abolished in cells preincubated with poly(ADP-ribose)polymerase inhibitor, 3-aminobenzamide. After VP-16 administration, we have observed that the level of NAD is not heavily decreased. It is widely agreed that zinc exerts an inhibitory effect on the endonuclease(s) responsible for the fragmentation of DNA during apoptosis. After incubation of cells with zinc/VP-16 we have found the occurrence of apoptotic parameters even in the absence of internucleosomal DNA cleavage. The inhibition of DNA fragmentation prevents the activation of poly(ADP-ribose)polymerase activity. These results indicate that the activation of the enzyme towards the automodification reaction is strictly dependent on the appearance of DNA internucleosomal fragments and could represent a way to control enzyme activity.

Adenosine Monophosphate↗