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Biomedical subjects

G Ferraro

Publications and source records attributed to G Ferraro.

At least 37 records · Page 2Linked to original sources
PubMed2002

In vitro genotoxic evaluation of the medicinal plant Chenopodium ambrosioides L.

Chenopodium ambrosioides (Chenopodiaceae) is an anthelmintic herb used in Latin-America's folk medicine. The aim of this work is to evaluate genetic damage induced by decoction and infusion of this plant which were assayed in different concentrations (1, 10, 100, 1000 microg/ml), by addition of the extract to human lymphocyte cell cultures. The endpoints evaluated were chromosomal aberrations (CA), sister chromatid exchanges (SCE), cell proliferation kinetics (CPK) and mitotic indexes (MI). The repeated measure analysis of variance was used for statistic evaluation of the results. The results showed (a) a statistical increase in the percentage of cells with CA and in the frequency of SCE when cultures were exposed to both preparations of Paico, (b) a decrease in MI of both preparations assayed, although no modification in the CPK values either in the infusion or in the decoction was observed. These results suggest a possible genotoxic effect of both preparations, probably due to different active principles.

Anthelmintics↗
PubMed2002

Progression of gastric enterochromaffin-like cells growth in Zollinger-Ellison syndrome and atrophic body gastritis patients.

BACKGROUND: Enterochromaffin-like cell hyperplasia of the gastric body mucosa occurs in hypergastrinaemic conditions such as atrophic body gastritis and Zollinger-Ellison syndrome. However, the time course of change or factors involved are not known. AIMS: To compare the rate of change of enterochromaffin-like cell proliferation in patients with atrophic body gastritis and Zollinger-Ellison syndrome. PATIENTS: From a consecutive series of atrophic body gastritis and Zollinger-Ellison syndrome patients, studied at the time of first diagnosis, 10 atrophic body gastritis (4 with pernicious anaemia) and 14 Zollinger-Ellison syndrome (4 with multiple endocrine neoplasia type 1) patients were followed-up for a median time of 48 months. METHODS: At entry and during follow-up patients underwent: plasma gastrin determination, endoscopic sampling of body mucosa for qualitative assessment of enterochromaffin-like cell hyperplasia pattern and degree of glandular atrophy, qualitative and morphometric analyses of body mucosa endocrine cells. RESULTS: At time of diagnosis, enterochromaffin-like cell lesions were more severe in atrophic body gastritis than in Zollinger-Ellison syndrome. During follow-up, no significant variations were observed in gastrin values, enterochromaffin-like cell patterns and grade of body mucosa atrophy in atrophic body gastritis. In contrast, gastrin levels were significantly increased [median 1200 (235-2625) vs 1947 (225-5200) pg/ml; p<0.001)] as was total volume density of enterochromaffin-like cells [median 1.60 (0.53-4.06) vs 3.18 (1.35-21.13)% of mucosal epithelial component; (p<0.005)] in Zollinger-Ellison syndrome. Micronodular hyperplasia of enterochromaffin-like cells, present in only one patient at diagnosis, was observed in 8 Zollinger-Ellison syndrome patients at follow-up. CONCLUSIONS: These data suggest that the progression of enterochromaffin-like cell growth in human gastric mucosa requires an increase of and/or a prolonged exposure to severe hypergastrinaemia.

Adult↗
PubMed2002

Prospective study of the ability of histamine, serotonin or serum chromogranin A levels to identify gastric carcinoids in patients with gastrinomas.

BACKGROUND: Chronic hypergastrinaemia causes gastric enterochromaffin cell proliferation and carcinoid tumours. The only reliable means to diagnose enterochromaffin cell changes/carcinoids is by biopsy. AIM: To assess whether serum histamine, chromogranin A or serotonin and urinary N-methylimidazoleacetic acid or 5-hydroxyindoleacetic acid correlate with advanced enterochromaffin cell changes or gastric carcinoids in patients with gastrinomas. METHODS: Consecutive patients (n=145) had the above assays and endoscopy with gastric biopsies. RESULTS: Lower N-methylimidazoleacetic acid and chromogranin A levels (P < 0.0001) occurred in disease-free patients. In patients with active disease, the fasting serum gastrin levels correlated (P < 0.0001) with both chromogranin A and N-methylimidazoleacetic acid levels. Chromogranin A (P=0.005), but not N-methylimidazoleacetic acid, serotonin, 5-hydroxyindoleacetic acid or histamine levels, correlated with the enterochromaffin cell index. Carcinoids, but not advanced enterochromaffin cell changes only, were associated with higher chromogranin A and N-methylimidazoleacetic acid levels. CONCLUSIONS: Serum chromogranin A levels and urinary N-methylimidazoleacetic acid levels, but not serum histamine or serotonin or urinary 5-hydroxyindoleacetic acid, correlate with the presence of gastric carcinoids. However, no assay identified patients with advanced enterochromaffin cell changes only with high sensitivity/specificity. Thus, N-methylimidazoleacetic acid and chromogranin A levels are unable to identify patients with advanced changes in enterochromaffin cells and therefore neither can replace routine gastric biopsies.

Adult↗
PubMed2002

Immunomodulating properties of Argentine plants with ethnomedicinal use.

Five Argentine medicinal plants selected according to folk traditional or ethnomedical use, references and primary pharmacological screening; were chosen to elucidate their immunomodulating properties. Dichloromethane, methanolic and aqueous extracts of the aerial parts of Achyrocline flaccida (A. flaccida), Eupatorium arnottianum (E. arnottianum) and Eupatorioum buniifolium (E. buniifolium), leaves of Lithraea molleoides (L. molleoides) and leaves and stems of Phyllanthus sellowianus (P. sellowianus) were analyzed to disclose their effects on murine normal and tumor cell growth as well as on complement hemolytic activity. Modulation of cell growth was evaluated by tritiated thymidine incorporation while inhibition of complement activity was measured on both classical and alternative complement pathways (CP and AP respectively). The results obtained show that most of the extracts exerted inhibitory effect on tumor as well as on mitogen activated normal spleen cell growth. On tumor cells, IC50 ranged between 1-75 microg/ml for most of the extracts with the exception of dichloromethane of L. molleoides and P. sellowianus which required concentrations higher than 100 microg/ml to produce the effect. On mitogenic activated splenocytes, IC50 ranged between < 1 to 85 microg/ml with the exception of methanolic extract of E. buniifolium or P. sellowianus which were not effective on ConA or LPS stimulated splenocytes respectively. Only E. buniifolium was active on murine normal splenocytes proliferation (IC50 0.5-1.5 microg/ml). Finally, one (7%) of 15 extracts showed inhibition of complement activity on CP and 6 extracts (40%) presented moderate activity on CP. The dichloromethane extract of E. arnottianum was the most active (IC50 5 microg/ml), although remarkable effect was also obtained with dichloromethane and methanolic extracts of P. sellowianus (IC50 11.2 and 17.3 microg/ml respectively). Besides, 2 extracts (13%), dichloromethane extract of E. arnottianum and aqueous extract of P. sellowianus, showed moderate inhibition on AP.

Achyrocline↗
PubMed2002

The hypoglycemic effect of Phyllanthus sellowianus fractions in streptozotocin-induced diabetic mice.

Phyllanthus sellowianus Müller Arg. (Euphorbiaceae) is a plant used in folk medicine as a hypoglycemic and diuretic agent. The present study describes the hypoglycemic effect of fractions obtained from the stem barks of P. sellowianus using a bioassay-guided fractionation protocol and streptozotocin-induced hyperglycemic mice. The aqueous extract was partitioned between dichloromethane and butanol to yield the dichloromethane (D), butanol (B) and the remaining aqueous (A) fractions. Fractions B and A, administered at the dose of 200 mg/kg p.o., caused a significant reduction in blood glucose concentration at 6 and 9 h, while the same dose of fraction D was ineffective. The reduction in blood glucose levels obtained with the B and A fractions was similar to that observed with glibenclamide (10 mg/kg) which was used as a reference for the hypoglycemic activity. Phytochemical analysis of fractions B and A revealed the presence of flavonoid compounds, of which rutin and isoquercitrin were the major constituents, respectively. The possible involvement of these flavonoids in the hypoglycemic effect of the active fractions is discussed.

Animals↗
PubMed2002

Prevention and treatment of keloids with intralesional verapamil.

BACKGROUND: The current treatment of keloids is based on surgery, medical therapy and physical treatment. The optimal treatment remains undefined. OBJECTIVE: This clinical study determines the effectiveness of verapamil hydrochloride on the prevention and treatment of keloids. METHODS: Two groups of patients with keloids were divided according to lesion site and age. The first group was treated by perilesional surgical excision of keloids and topical silicone, combined with adjuvant treatment of intralesional 2.5 mg/ml verapamil hydrochloride injections administered at timed intervals. The second group served as control, receiving the same treatment except the verapamil hydrochloride. RESULTS: A periodical examination to check specific clinical parameters and an 18-month follow-up determined that keloids were cured in 54% of the cases in the first group, compared to 18% in the second group. Moreover, in the remaining 36% of patients in the first group in whom keloids recurred, there was an improvement in size and above all in consistence. CONCLUSION: These findings suggest that verapamil hydrochloride is an effective tool for the prevention and therapy of keloids.

Administration, Topical↗
PubMed2001

First cyclotide from Hybanthus (Violaceae).

Hypa A, a novel macrocyclic polypeptide containing 30 amino acid residues, has been isolated from the n-butanol extract of the Argentine plant Hybanthus parviflorus. The sequence, cyclo-(SCVYIPCTITALLGCSCKNKVCYNGIPCAE), was determined by automated Edman degradation, quantitative amino acid analysis and nanospray MS/MS(2). Three intramolecular disulfide bridges stabilize the cyclic peptide backbone of hypa A. Using these structural features to classify the peptide as a cyclotide, we extended the distribution of that substance class to a new genus, and now propose a uniform nomenclature for cyclotides.

Amino Acid Sequence↗
PubMed2001

Phenolic compounds in seven South American Ilex species.

Ilex paraguariensis (common name: 'mate' or 'yerba mate') is used for the preparation of the most popular tea-like beverage of South America. Choleretic, hypocholesteremic, antioxidant, hepatoprotective and bitter taste properties of mate are attributed to the phenolic constituents of the leaves. I. paraguariensis has seven local congeneric substitutes or adulterants: I. brevicuspis; I. theezans; I. microdonta; I. dumosa var. dumosa; I. taubertiana; I. pseudobuxus; I. integerrima; and I. argentina. An HPLC method using UV with Photodiode Array Detector was developed for the identification and quantification of caffeoyl derivatives (caffeic acid, chlorogenic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid) and flavonoids (quercetin, rutin and kaempferol) in these species. I. paraguariensis showed a higher content of flavonoids and caffeoyl derivatives than the other assayed species.

Caffeic Acids↗
PubMed2001

Antimicrobial activity of Argentine plants used in the treatment of infectious diseases. Isolation of active compounds from Sebastiania brasiliensis.

Different extracts of Sebastiania brasiliensis, Sebastiania klotszchiana, Polygonum punctatum, Lithraea molleoides and Myrcianthes cisplatensis, all plants growing in Entre Ríos Province and traditionally used as antiseptics, were tested against a set of Gram positive and Gram negative bacteria and fungi. All the species, with the exception of M. cisplatensis, presented activity against some of the microorganisms tested. A 50% hydroalcoholic extract of S. brasiliensis was selected for bioguided fractionation. Two antimicrobial compounds identified as methylgallate (MIC 128 microg/ml) and protocatechuic acid (MIC 128 microg/ml) were isolated apart from quercetin, kaempferol, quercitrin and gallic acid.

Anti-Bacterial Agents↗
PubMed2001

Auditory event-related potentials (P300) in epileptic patients.

Auditory event-related potentials (AERPs) were recorded during an auditory oddball paradigm in 108 epileptics and in 32 healthy controls. P300 latency varied in relationship with age only in controls. Symptomatic epileptics had significantly prolonged P300 mean latency compared to those without detectable brain lesion(s) on MR scan. Moreover, these latter patients were compared on the basis of epilepsy duration, type of seizure, seizure frequency and antiepileptic treatment; the application of a multiple regression model showed a significant relationship between P300 latency prolongation and epilepsy duration, seizure frequency and polytherapy.

Adolescent↗
PubMed2001

Phenolic compounds with anti-inflammatory activity from Eupatorium buniifolium.

Anti-inflammatory activity was detected in the CH(2)Cl(2) extract of the aerial parts of Eupatorium buniifolium using the TPA-mouse ear model. Three compounds isolated from this extract, by bioassay-guided fractionation, significantly inhibited the inflammatory response. The compounds were identified as 5,7,5'-trihydroxy-3,6,2',4'-tetramethoxyflavone (1), scopoletin (2) and centaureidin (3) which inhibited the edema by 67.3 %, 59.8 % and 49.7 %, respectively, at a dose of 1 mg/ear.

Administration, Topical↗
PubMed2001

First endoscopic-histologic follow-up in patients with body-predominant atrophic gastritis: when should it be done?

BACKGROUND: Body-predominant atrophic gastritis is considered a risk factor for gastric cancer and carcinoid. Timing of follow-up for patients with this disorder has not been defined. This study was undertaken to determine the optimal time for the first endoscopic/histologic follow-up in patients with body-predominant atrophic gastritis. METHODS: Forty-two patients with body-predominant atrophic gastritis were randomly assigned to 1 of 2 follow-up intervals: group A (n = 22) at 24 months and group B (n = 20) at 48 months. At baseline and follow-up patients underwent gastroscopy at which biopsies were obtained from the antrum and body for histopathology and evaluation for enterochromaffin-like cells. RESULTS: In group A patients, 2 antral hyperplastic polyps (9.1%) were present at baseline and 4 antral hyperplastic polyps (18.2%) were found at follow-up. In group B patients, baseline gastroscopy revealed 2 antral hyperplastic polyps (10%) and follow-up 2 antral hyperplastic polyps (10%) and 1 carcinoid tumor (5%) in the body. Atrophy and intestinal metaplasia scores in gastric body and antral mucosa in both groups did not change significantly between baseline and follow-up, except an increase in antral mucosa atrophy in group B patients (p = 0.02) was revealed. CONCLUSIONS: The results of this study indicate that performing the first follow-up in patients with body-predominant atrophic gastritis need not be earlier than at 4 years after diagnosis. This interval is satisfactory for detection of potential neoplastic lesions.

Adult↗
PubMed2001

Different intracellular signals coupled to the antiproliferative action of aqueous crude extract from Larrea divaricata Cav. and nor-dihydroguaiaretic acid on a lymphoma cell line.

In this paper, we report the effect of standard NDGA, as compared to that of an aqueous extract of Larrea divaricata Cav., on BW 5147 lymphoma cell-line proliferation. To determine the mechanism of action, the effects of both on the level of intracellular cAMP, protein kinase C activity and calcium influx were studied. Moreover, the NDGA present in the aqueous extract of the plant was quantified. The aqueous extract and the standard NDGA showed antiproliferative action against these cells. While the antiproliferative activity of the aqueous extract was mediated by an increase in cAMP levels, and inhibition of PKC and calcium influx, the antiproliferative activity of NDGA was related only to the inhibition of PKC. Considering the amount of NDGA detected in the aqueous extract of the plant, at the concentrations analyzed in this case, antiproliferative activity of Larrea divaricata cannot be attributed to this compound, but could have an additive effect on the activity of other compounds.

Antineoplastic Agents↗
PubMed2001

The antral mucosa as a new site for endocrine tumors in multiple endocrine neoplasia type 1 and Zollinger-Ellison syndromes.

Carcinoid tumors were identified in the antro-pyloric mucosa of four patients with multiple endocrine neoplasia type 1 (MEN-1)/Zollinger-Ellison syndrome, accounting for 8.7% of 46 patients with this condition examined by endoscopy and histology. In contrast, no tumors were found in the antral biopsies from 124 cases of sporadic Zollinger-Ellison syndrome (P < 0.001), indicating a prominent role for the MEN-1 gene defects in tumor development. Immunohistochemically the tumors did not express the hormones produced by antral endocrine cells (gastrin, somatostatin, serotonin). In contrast, two of them were diffusely immunoreactive for the isoform 2 of the vesicular monoamine transporter (VMAT-2), a marker specific for the gastric nonantral enterochromaffin-like (ECL) cells. In one of these patients a second antral VMAT-2-positive carcinoid was seen 21 months after the first diagnosis. The other two antral carcinoids were unreactive for VMAT-2. Multiple ECL cell tumors were found in the gastric body-fundus mucosa of the two patients with VMAT-2-positive, but not in those with VMAT-2-negative, antral carcinoids. In one case, the former tumors were diagnosed 22 months after the detection of the antral tumor. We conclude that the antral mucosa is an additional tissue that may harbor endocrine tumors in MEN-1 syndrome. These tumors did not express the phenotype of normal antral endocrine cells and, in at least two cases, were identified as ectopic ECL cell carcinoids.

Adult↗
PubMed2000

Classification of gastric endocrine cells at the light and electron microscopical levels.

This review discusses the current concepts for the classification of gastric endocrine cells subdivided according to the type of mucosa in which they are located. In the oxyntic mucosa, the most important cell type is the ECL cell, involved in the synthesis and secretion of histamine. Proteins involved in many aspects of the biology of ECL cells including the response to the gastrin stimulus, membrane transport and docking, prevention of apoptosis, calcium homeostasis, autocrine activity, and maintenance of the differentiated cell phenotype have been localized to this cell type. Other cells of the oxyntic mucosa include: the D and EC cells producing somatostatin and serotonin, respectively, delivered through long cell processes; the X (or A-like) cells, possibly producing endothelin; and the D(1) and P cells of unknown function and possibly representing morphological variants of other cell types. In the antral mucosa, the three important cell types are represented by: the gastrin-producing G cells; the somatostatin-producing D cells, which are anatomically and functionally associated with G cells; and the serotonin-producing EC cells, which are located at the bottom of antral glands.

Animals↗
PubMed2000

Antinociceptive effect of some Argentine medicinal species of Eupatorium.

Eupatorium laevigatum, E. arnottianum and E. subhastatum, plants used in Argentine folk medicine for the treatment of inflammation and pain related problems, were evaluated for analgesic activity. The infusions of these species (500 mg/kg, p.o.) produced a reduction in the number of stretches of 46.6%, 41.5% and 35.6% respectively, in the acetic acid induced writhing test. This antinociceptive effect of the infusions was not reversed by pretreatment with naloxone. The infusions studied did not produce antinociceptive effects when assayed in the hot plate test. These results suggest that the analgesic activity is exerted by a mechanism unrelated to interaction with opioid systems.

Analgesics↗
PubMed2000

Sampling strategies for analysis of enterochromaffin-like cell changes in Zollinger-Ellison syndrome.

To investigate the optimum number of biopsy specimens to be obtained for enterochromaffin-like (ECL) cell monitoring in hypergastrinemic patients and ECL cell regional variations potentially influencing the results, qualitative ECL cell changes were assessed in 149 patients with Zollinger-Ellison syndrome using jumbo biopsy specimens and a systematic sampling procedure of 4 areas each from the lesser or greater curvature of the gastric body. Of 1,176 specimens examined, 1,101 were adequate. The correlation was excellent between different sites within the greater or lesser curvature. In contrast, a normal ECL cell pattern was more frequent in the lesser curvature, whereas linear hyperplasia was more frequent in the greater curvature. Dysplastic lesions and carcinoid tumors in endoscopically unremarkable mucosa were detected in 3.4% and 1.2% of biopsy specimens, respectively, and were equally distributed between the lesser and greater curvature. Their chances of being diagnosed were related to the number of specimens examined. Extensive sampling of both the lesser and greater curvature is recommended for early diagnosis of dysplastic and/or carcinoid lesions in patients at risk. In contrast, limited sampling in the greater curvature seems to be adequate in patients with no risk for carcinoid development.

Biopsy↗