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Biomedical subjects

L Barbieri

Publications and source records attributed to L Barbieri.

At least 37 records · Page 2Linked to original sources
PubMed1998

The effect of ribosome-inactivating proteins on the ribosome from the hyperthermophilic archaeon Sulfolobus solfataricus.

Protein synthesis in the thermoacidophilic archaeon Sulfolobus solfataricus (Ss) was inhibited by polynucleotide:adenosine glycosylase activity of some type 1 ribosome-inactivating proteins (RIP). The target of RIP was S. solfataricus rRNA that was depurinated thus producing inactive ribosomes. The amount of RIP required to half-inactivated Ss-ribosomes was comparable to that needed for eubacterial ribosomes, but two orders of magnitude higher than that required for mammalian ribosomes. In addition, RIP treated Ss-ribosomes were also less efficient in stimulating the ribosome dependent GTPase activity of the S. solfataricus elongation factor 2 (SsEF-2) thus suggesting that the inhibition of protein synthesis was probably due to the lack of the interaction between depurinated Ss-ribosomes and SsEF-2. Since SsEF-2 protects Ss-ribosomes against RIP activity it can be hypothesised that also on Ss-ribosomes the sites of interaction for the translocation factor 2 and the RIP are topographically close.

Archaeal Proteins↗
PubMed1997

Type 1 ribosome-inactivating proteins are the most abundant proteins in iris (Iris hollandica var. Professor Blaauw) bulbs: characterization and molecular cloning.

The most abundant protein of Iris bulbs has been identified as a type 1 ribosome-inactivating protein (RIP). Analysis of the purified proteins and molecular cloning of the corresponding cDNAs demonstrated that this type 1 RIP is a mixture of three isoforms that exhibit a high degree of sequence identity and have similar, though not identical, ribosome-inactivating and polynucleotide:adenosine glycosidase activities. The accumulation of large quantities of type 1 RIP in a vegetative storage organ suggests that this presumed defence-related protein also plays a role in the nitrogen-storage metabolism of the bulb.

Amino Acid Sequence↗
PubMed1997

Ribosome-inactivating lectins with polynucleotide:adenosine glycosidase activity.

Lectins from Aegopodium podagraria (APA), Bryonia dioica (BDA), Galanthus nivalis (GNA), Iris hybrid (IRA) and Sambucus nigra (SNAI), and a new lectin-related protein from Sambucus nigra (SNLRP) were studied to ascertain whether they had the properties of ribosome-inactivating proteins (RIP). IRA and SNLRP inhibited protein synthesis by a cell-free system and, at much higher concentrations, by cells and had polynucleotide:adenosine glycosidase activity, thus behaving like non-toxic type 2 (two chain) RIP. APA and SNAI had much less activity, and BDA and GNA did not inhibit protein synthesis.

3T3 Cells↗
PubMed1997

Polynucleotide:adenosine glycosidase activity of ribosome-inactivating proteins: effect on DNA, RNA and poly(A).

Ribosome-inactivating proteins (RIP) are a family of plant enzymes for which a unique activity was determined: rRNAN-glycosidase at a specific universally conserved position, A4324in the case of rat ribosomes. Recently we have shown that the RIP from Saponaria officinalis have a much wider substrate specificity: they are actually polynucleotide:adenosine glycosidases. Here we extend studies on substrate specificity to most known RIP: 52 purified proteins, both type 1 (single-chain) and type 2 (two chain, an enzymatic chain and a lectin chain) were examined for adenine release on various substrates including RNAs from different sources, DNA, and poly(A). All RIP depurinated extensively DNA and some released adenine from all adenine-containing polynucleotides tested. From experimental evidence the entire class of plant proteins, up to now called ribosome-inactivating proteins, may be classified as polynucleotide:adenosine glycosidases. The newly identified substrates may be implicated in the biological role(s) of RIP.

Adenosine↗
PubMed1997

New ribosome-inactivating proteins with polynucleotide:adenosine glycosidase and antiviral activities from Basella rubra L. and bougainvillea spectabilis Willd.

New single-chain (type 1) ribosome-inactivating proteins (RIPs) were isolated from the seeds of Basella rubra L. (two proteins) and from the leaves of Bougainvillea spectabilis Willd. (one protein). These RIPs inhibit protein synthesis both in a cell-free system, with an IC50 (concentration causing 50% inhibition) in the 10(-10) M range, and by various cell lines, with IC50S in the 10(-8)-10(-6) M range. All three RIPs released adenine not only from rat liver ribosomes but also from Escherichia coli rRNA, polyadenylic acid, herring sperm DNA, and artichoke mottled crinkle virus (AMCV) genomic RNA, thus being polynucleotide:adenosine glycosidases. The proteins from Basella rubra had toxicity to mice similar to that of most type 1 RIPs (Barbieri et al., 1993, Biochim Biophys Acta 1154: 237-282) with an LD50 (concentration that is 50% lethal) < or = 8 mg.kg-1 body weight, whilst the RIP from Bougainvillea spectabilis had an LD50 > 32 mg.kg-1. The N-terminal sequence of the two RIPs from Basella rubra had 80-93% identity, whereas it differed from the sequence of the RIP from Bougainvillea spectabilis. When tested with antibodies against various RIPs, the RIPs from Basella gave some cross-reactivity with sera against dianthin 32, and weak cross-reactivity with momordin I and momorcochin-S, whilst the RIP from Bougainvillea did not cross-react with any antiserum tested. An RIP from Basella rubra and one from Bougainvillea spectabilis were tested for antiviral activity, and both inhibited infection of Nicotiana benthamiana by AMCV.

3T3 Cells↗
PubMed1997

Recovery of spontaneous erectile function after nerve-sparing radical retropubic prostatectomy with and without early intracavernous injections of alprostadil: results of a prospective, randomized trial.

PURPOSE: This study was aimed at assessing prospectively the effect of postoperative intracavernous injections of alprostadil on the recovery of spontaneous erectile function after nerve-sparing radical retropubic prostatectomy. MATERIALS AND METHODS: A total of 30 potent patients with clinically localized prostate cancer (clinical stage B1 or B2, Gleason sum 7 or greater, prostatic specific antigen less than 20 ng./ml.) underwent nerve-sparing radical retropubic prostatectomy and was subsequently randomized to alprostadil injections 3 times per week for 12 weeks (group 1, 15 patients) or observation without any erectogenic treatment (group 2, 15 patients). Patients were assessed at the 6-month followup by sexual history, physical examination, color Doppler sonography of the cavernous arteries and polisomnographic recording of nocturnal erections. RESULTS: In group 1, 12 patients (80%) completed the entire treatment schedule and were evaluated at the long-term followup. Eight patients in this group (67%) reported the recovery of spontaneous erection sufficient for satisfactory sexual intercourse, compared with 3 patients (20%) in group 2. The difference between the 2 groups was statistically significant (p <0.01). In group 1, all but 1 patient reporting normal postoperative erections also showed normal erections at nocturnal testing, whereas color Doppler sonography demonstrated normal penile hemodynamics in all of them. In these patients, failures were the result of cavernous veno-occlusive dysfunction (2 cases, 17%) and cavernous nerve injury (2 cases, 17%). In group 2, patients with normal erections showed both normal nocturnal testing and penile hemodynamics, whereas failures were the result of cavernous veno-occlusive dysfunction (8 cases, 53%), cavernous arterial insufficiency (2 cases, 13%) or cavernous nerve injury (3 cases, 20%). Complications in patients treated with alprostadil injections accounted for 2 cases (13%) of a penile nodule and 1 further case (6%) of prolonged penile erection. Complications were not seen in group 2 patients. CONCLUSIONS: Early postoperative administration of alprostadil injections significantly increases the recovery rate of spontaneous erections after nerve-sparing radical retropubic prostatectomy. It is our belief that programmed vasoactive injections improve cavernous oxygenation, thereby limiting the development of hypoxia-induced tissue damage. The potential complications related to the use of intracavernous injections must be clearly explained to patients.

Aged↗
PubMed1997

[Effectiveness of the Palmaz Schatz stent in elderly patients with unstable angina: factors predictive of short-term and long-term events].

INTRODUCTION: To evaluate clinical, procedural and therapeutical predictors of in- and out-hospital events in the elderly, we analyzed 69 consecutive patients (age: 74, range: 70-87) with unstable angina who successfully underwent Palmaz Schatz coronary stenting. METHODS: Between March 1991 and March 1994, after the stenting procedure, a cohort of 38 patients (AC) was treated with iv heparin for 48 hours, warfarin (dosage titrated on INR) and dipiridamole (75 mg tid) for 3 months, aspirin (325 mg a day) chronically; between April 1994 and April 1995, after 48 hours of iv heparin, a second cohort of 31 patients (NO AC) received subcutaneous low molecular weight heparin (4000 U a day) for a week, ticlopidine (250 bid) for 1 month, and aspirin (100 mg a day) chronically. NO AC patients showed, by protocol, a higher postdilatation pressure (14 +/- 2 vs 9 +/- 3 atm, p < 0.0001). RESULTS: The 2 cohorts of patients were similar with respect to baseline clinical and angiographic findings. A shorter hospital stay (5 +/- 2 vs 10 +/- 6 days, p < 0.0001) and a lower incidence of in-hospital events were seen in the NO AC group (3.2 vs 24%, p = 0.028), both by a reduction of ischaemic events (3.2 vs 10.5%, p = ns) and hemorrhagic events (0 vs 13.2%, p = 0.03). During a mean follow-up of 21 +/- 13 months, NO AC patients did not show a significant lower rate of out-hospital events (1 year event-free survival respectively 94.7% in NO AC cohort vs 85.7% in AC cohort, p = ns). At logistic regression model, anticoagulant therapy (OR 10.89, Cl 1.39-85.28, p < 0.05) and refractory angina (Braunwald C3) (OR 5.70, Cl 1.12-29.03, p < 0.05) were significantly related to the incidence of acute events, while refractory angina (OR 5.76, Cl 1.27-26.00, p = 0.02) and multivessel disease (OR 3.31, Cl 0.89-12.20, p = 0.07) to the occurrence of late cardiac events, particularly for a higher risk of non-target site new revascularizations. Stent implantation on saphenous vein graft was also associated to a higher risk of repeating a revascularization of non-treated sites (20 vs 4%, p = 0.021). CONCLUSIONS: In elderly with unstable angina treated with Palmaz Schatz stenting, NO AC patients showed a significant reduction of in-hospital events without a subsequent higher risk of late events. In addition, refractory angina, multivessel disease and stent implantation on saphenous vein graft were the other main clinical variables predictive of out-hospital events particularly for higher risk of non-target site new revascularizations.

Age Factors↗
PubMed1996

A systemic antiviral resistance-inducing protein isolated from Clerodendrum inerme Gaertn. is a polynucleotide:adenosine glycosidase (ribosome-inactivating protein).

Two systemic antiviral resistance-inducing proteins, CIP-29 and CIP-34, isolated from Clerodendrum inerme Gaertn. leaves, were tested for ribosome-inactivating properties. It was found that CIP-29 has the characteristics of a polynucleotide:adenosine glycosidase (ribosome-inactivating protein), in that it inhibits protein synthesis both in cell-free systems and, at higher concentrations, in cells, and releases adenine from ribosomes, RNA, poly(A) and DNA. As compared with other known RIPs, CIP-29 deadenylates DNA at a high rate, and induces systemic antiviral resistance in susceptible plants.

Adenine↗
PubMed1996

Polynucleotide: adenosine glycosidase activity of saporin-L1: effect on DNA, RNA and poly(A).

The ribosome-inactivating proteins (RIPs) are a family of plant enzymes for which a unique activity has been determined: rRNA N-glycosidase, which removes adenine at a specific universally conserved position (A4324 in the case of rat ribosomes). Here we report that saporin-L1, a RIP from the leaves of Saponaria officinalis, recognizes other substrates, including RNAs from different sources, DNA and poly(A). Saporin-L1 depurinated DNA extensively and released adenine from all adenine-containing polynucleotides tested. Adenine was the only base released from DNA or artificial polynucleotides. The characteristics of the reactions catalysed by saporin-L1 have been determined: optimal pH and temperature, ionic requirements, and the kinetic parameters Km and kcat. The reaction proceeded without cofactors, at low ionic strength, in the absence of Mg2+ and K+. Saporin-L1 had no activity towards various adenine-containing non-polynucleotide compounds (cytokinins, cofactors, nucleotides). This plant protein may now be classified as a polynucleotide: adenosine glycosidase.

Animals↗
PubMed1996

Activities associated with the presence of ribosome-inactivating proteins increase in senescent and stressed leaves.

The ribosome-inactivating proteins (RIPs) from Hura crepitans and Phytolacca americana release adenine from herring sperm DNA. Leaf extracts from these plants show the same enzymatic activities as the RIPs. The translation inhibitory activity and the activity on DNA are both increased in the leaves of both plants during senescence or when subjected to heat or osmotic stress. It is proposed that a physiological role of RIPs could be to intervene in the death of plant cells.

Adenine↗
PubMed1996

Financial impact in the Italian Health Service of laparoscopic versus laparotomic surgery for the treatment of ovarian cysts.

To assess the cost of two procedures for the removal of ovarian cysts, 200 pre-menopausal women were recruited for the surgical removal of ovarian cysts by laparoscopy (n = 100) and laparotomy (n = 100) according to case-control criteria. Patients operated by laparoscopy (mean age +/- SD 32.22 +/- 9.98 years) and laparotomy (mean age +/- SD 29.57 +/- 6.62 years) for ovarian cysts (mean diameters +/- SD 4.98 +/- 3.62 and 4.83 +/- 2.78 cm) had a post-surgical hospital stay of 3.12 +/- 0.41 and 7.25 +/- 1.08 days (P < 0.001) respectively. The total rate of complications occurring in patients operated by laparoscopy was 9 versus 53% (P < 0.001) of those operated by laparotomy; body temperature > 38 degrees C was recorded in 52/100 of patients operated by laparotomy versus 6/100 of those operated by laparoscopy. The mean cost for each pure surgical treatment performed by laparoscopy was US $498.17 versus US $642.47 when it was performed by laparotomy (P < 0.001). The laparoscopic surgical approach is more expensive in the first 36 operations, thereafter becoming cheaper. The mean of the entire overall expenditure was US $1142.08 and US $2138.72 for laparoscopy and laparotomy (P < 0.001) respectively. The entire expenditure for laparoscopy is higher than laparotomy only until eight operations. In conclusion, laparoscopy versus laparotomy has resulted in a saving of US $14,429.3 for 100 operations while the saving on entire costs was US $99,664.8.

Adult↗
PubMed1996

The effect of intracorporeal injection plus genital and audiovisual sexual stimulation versus second injection on penile color Doppler sonography parameters.

PURPOSE: We assessed whether genital and audiovisual sexual stimulation following 1 or 2 intracorporeal injections caused the greatest changes in penile hemodynamics as recorded by color Doppler sonography. MATERIALS AND METHODS: A total of 50 impotent patients underwent multiphasic color Doppler sonography of the cavernous arteries before and after intracorporeal injection (phase 1), subsequent genital and audiovisual sexual stimulation (phase 2), a second injection (phase 3) and repeat genital and audiovisual sexual stimulation (phase 4). Peak systolic velocity, end diastolic velocity, resistance index and erectile response were studied. RESULTS: Penile erection after injection 1 was upgraded in 41 patients (82%) by genital and audiovisual sexual stimulation. Further upgrading due to injection 2 with stimulation was noted in 11 patients (22%). Among the patients who completed the 4 phases of the test the maximal peak systolic velocity was noted after 1 and 2 injections in 20 (59%) and 14 (41%), respectively. The resistive index was always increased by genital and audiovisual sexual stimulation compared to post-injection values. The maximal resistive index occurred after initial and repeat genital and audiovisual sexual stimulation in 15 (48%) and 16 (52%) patients, respectively. After injection 1 with genital and audiovisual sexual stimulation, impotence was diagnosed as nonvasculogenic in 14 patients (28%), arteriogenic in 9 (18%), venogenic in 17 (34%) or mixed arteriovenogenic in 10 (20%). After injection 2 with stimulation these results were noted in 18 (36%), 9 (18%), 13 (26%) and 10 (20%) patients, respectively. Thus, there were 4 false-positive cases (8%) of venogenic impotence. CONCLUSIONS: To study cavernous artery inflow and veno-occlusive function, color Doppler sonography should be performed after injection plus genital and audiovisual sexual stimulation. When the erectile response does not equal the maximal physiological erection reported by the patient, a second injection with stimulation should be given.

Audiovisual Aids↗
PubMed1996

AMS 700 CX inflatable penile implants for Peyronie's disease: functional results, morbidity and patient-partner satisfaction.

This study was designed to clarify the functional results, morbidity and the patient-partner satisfaction observed with, the American Medical System 700 CX three-piece inflatable prosthesis in the treatment of impotence associated with Peyronie's disease. Thirty-three patients were treated and additional plaque surgery was performed in 13 cases (40%). Within 10 days of surgery, four patients (12%) developed a wound infection which was treated conservatively and one patient (3%) experienced glandular ischemia. At the 6-week follow-up, complete penile straightening was achieved in 23 patients (70%), while penile rigidity was considered optimal by all patients. On the contrary, the penis was considered short by 10 patients (30%). Five diabetic patients (15%) complained of severe scrotal and penile pain during full activation of the implant and in one of these patients (3%) the implant had to be removed. Due to spontaneous erections occurring after implant activation one patient (3%) required replacement of the reservoir from the Retzius space into the peritoneum. At the long-term follow-up (mean +/- SE: 17 +/- 2.2 months), 23 patients were evaluated and all found to be engaging in intercourse with the prosthesis. However, five patients (21%) and three of the 13 partners (25%) assessed were not yet completely satisfied. The American Medical System CX700 inflatable penile prosthesis obtains complete penile straightening in 70% and rigidity in 100% of impotent patients with Peyronie's disease. Patients should be fully informed about possible surgical morbidity and actual post-operative penile length.

Coitus↗
PubMed1995

Ribosome-inactivating proteins (RNA N-glycosidases) from the seeds of Saponaria ocymoides and Vaccaria pyramidata.

From the seeds of the Caryophyllaceae Saponaria ocymoides and Vaccaria pyramidata two proteins were purified which have the properties of the type-1 (single-chain) ribosome-inactivating proteins [reviewed by Barbieri, L., Battelli, M. G. & Stirpe, F. (1993) Ribosome-inactivating proteins from plants, Biochim. Biophys. Acta 1154, 237-282]. The proteins have molecular masses of 30.2 kDa (S. ocymoides) and 28.0 kDa (V. pyramidata) and pI greater than 9.5, their N-terminal amino acid sequences are similar to those of saporin-S6 and dianthin 30, ribosome-inactivating proteins from other Caryophyllaceae, and they partially cross-react with sera against these proteins. Both proteins inhibit protein synthesis by a rabbit-reticulocyte lysate with IC50 (concentrations giving 50% inhibition) below 10(-10) M, have a smaller effect on poly(U)-directed phenylalanine polymerisation by rat liver ribosomes (nanomolar IC50, approximately) and on protein synthesis by various cell lines (IC50 ranging from 4 nM to > 3000 nM) and possess rRNA N-glycosidase activity, releasing 1 mol adenine/ribosome.

Amino Acid Sequence↗
PubMed1995

Effects and molecular action of ribosome-inactivating proteins on ribosomes from Streptomyces lividans.

The effects of 29 type 1 and 2 type 2 ribosome-inactivating proteins (RIPs) from plants on polyuridylic acid-directed polyphenylalanine synthesis carried out by purified ribosomes from Streptomyces lividans were studied. Only dianthin 32, saporins R1 and R3, momordin I, trichokirin, Hura crepitans RIP 5 from latex, crotins 2 and 3, and PAPs C, R, and S, inhibited polyphenylalanine synthesis. Both the type 2 RIPs ricin and volkensin were ineffective on translation. The magnesium concentration affected the inhibition of translation to a considerable extent. Upon treatment with inhibitory RIPs, extraction of rRNA and further treatment with acid aniline, S. lividans ribosomes released an RNA fragment of about 130 nucleotides. The 5' terminal sequence of this rRNA fragment was 5'-GAGGACCGGGACGGACGAACCUCUGGUGUGCCAGUUGU-3', similar to the sequence obtained in Escherichia coli. This indicates that the most probable molecular action of these RIPs on S. lividans and E. coli ribosomes is the same: depurination of the rRNA at a site relevant to the translation mechanism and that has been highly conserved throughout evolution.

Base Sequence↗
PubMed1995

Antihistone antibodies in scleroderma.

BACKGROUND: Antihistone antibodies (AHA) are usually considered the serological marker of drug-induced lupus erythematosus, but recently they have been found in patients with systemic scleroderma (SSc) and morphea. OBJECTIVE AND METHODS: We determined AHA in 43 patients with SSc, 4 patients with overlap syndrome and 11 with morphea. RESULTS AND CONCLUSIONS: AHA were demonstrated in 41.8% of the SSc patients and in 36.3% of the morphea patients. Only 1 patient with overlap syndrome had AHA. Our SSc patients with AHA had frequent cardiac and renal involvements suggesting a prognostic value of AHA. In our morphea patients AHA did not correlate with clinical features.

Adult↗
PubMed1995

Improved minimally-invasive assessment of penile haemodynamics: the combination of colour Doppler sonography and injection-stimulation test.

The aim of this study was to assess the diagnostic value of erotically enhanced penile colour Doppler sonography as a minimally invasive tool to evaluate penile haemodynamics. Colour Doppler sonography was used to study the cavernosal arteries of 135 consecutive impotent patients after intracavernous injection of a vasoactive mixture (injection phase) and after subsequent genital and audiovisual sexual stimulation (stimulation phase). The erectile response was upgraded after the adjunct of genital and audiovisual stimulation in 36% of patients. Colour Doppler assessment performed after the stimulation phase identified 16% of patients as arteriogenic despite normal erections, and 7% of patients falsely diagnosed as venogenic after the injection phase. When colour Doppler sonography and the injection-stimulation test are performed together as a single diagnostic procedure the overall diagnostic accuracy is significantly enhanced.

Adult↗