PubMed Health⌕ Search

Biomedical subjects

A Prada

Publications and source records attributed to A Prada.

At least 37 records · Page 2Linked to original sources
PubMed2000

Fundic gland polyps: a still elusive entity on the eve of the year 2000.

Fundic gland polyps (FGPs) are tiny multiple sessile polyps of the acid-secreting gastric mucosa. They have been described both in a sporadic form, mainly in middle-aged females, and in a syndromic form, associated with familial adenomatous polyposis (FAP)-Gardner's syndrome and attenuated variants (AFAP). They share the same histology, characterised by superficial and deep cystic dilatations, shortened gastric pits, with an inconspicuous lamina propria. They have been for a long time described as innocuous lesions, but some recent reports have shown that FGPs may harbour dysplastic foci and ultimately (particularly syndromic polyps) gastric cancer. Factors influencing their genesis are unknown. A circulating factor in FAP patients has been postulated and a role of female hormones has been suggested for sporadic FGPs. Whereas patients with sporadic FGPs have normal basal acid output, normal fast serum levels of gastrin and pepsinogen I, the role of gastrin seems crucial for the development of cystic changes in flat body-fundus mucosa, and for the appearance of FGPs in patients with Zollinger-Ellison syndrome. A role of H. pylori induced gastritis has been excluded. Actually, patients with both sporadic and syndromic FGPs appear consistently free from H. pylori colonisation, again for an unknown factor(s). Some recent reports have claimed a role for omeprazole in the genesis of FGPs, a highly controversial issue. Ultimately, the nature of FGPs is still debated: some have interpreted them as hamartomatous lesions, others as a peculiar form of hyperplastic polyp.

Adenomatous Polyposis Coli↗
PubMed2000

[Nutritional evaluation of Lepidium meyenii (MACA) in albino mice and their descendants].

The Maca (Lepidium meyenii) is a Peruvian hypocotyl that grows exclusively between the 3700 and 4500 masl at the Peruvian Andes. Traditionally it is attributed nutritional, energizing, fertilizing properties among others. With the purpose of evaluate scientifically the nutritional property of Maca, we carried out a controlled study in two generations of albino Swiss mice (parents and breeding). The parents were aleatorily assigned to one of three nutritional schedules. The food of each group was prepared based on powder from a commercial balanced food (CBF) of which 30% was replaced by raw or cooked Maca according to the corresponding group or pure CBF in the control group. The groups were this way: 1) Raw Maca Group; 2) Cooked Maca Group; and, 3) Control Group. The results showed that the curves of growth were similar and adequate for the three groups. However, the cooked Maca group showed the best curve. These data were better observable in the second generation of animals, with significant statistical difference (p < 0.05). The CBF group had a better growth than raw Maca group. No signs of malnutrition nor overweight were observed in none of the groups. The serum values of total proteins and albumin were statistically superior for the mice group eating cooked Maca than that of the raw Maca and CBF groups. This study demonstrates, in a scientifical evaluation, one of the traditionally attributed properties of Maca, the nutritional capability.

Animal Nutritional Physiological Phenomena↗
PubMed1999

Quality assurance and colonoscopy.

BACKGROUND AND STUDY AIMS: Little is known concerning the usefulness and feasibility of quality assurance programs in gastrointestinal departments. The aim of this study was to identify the indicators of quality in colonoscopy, to check their use in clinical practice, and to identify their threshold values. MATERIALS AND METHODS: A prospective study was performed in four endoscopic units. In the first phase, a questionnaire was used to identify the indicators that were considered important and easy to record; in the second phase, the selected items were prospectively recorded. RESULTS: Data from 603 colonoscopies were evaluated. The selected indicators were: rate of cecal intubation, rate of examinations with normal findings, rates of complications, appropriateness of indications, use of a washing machine for disinfection, duration of the disinfection procedure, rate of procedures repeated due to poor colon cleansing, rate of operative procedures, length of waiting time, rate of procedures performed for follow-up of known disease, experience of the operator, and rate of procedures performed with the patient under conscious sedation. A striking difference emerged between the technical standards at three centers, which were fairly good, and the standard at the fourth center, which was less satisfactory. The length of the waiting time was high in all centers, as well as the rate of examinations conducted with an inappropriate indication. The rate of procedures performed under conscious sedation varied widely between the centers. CONCLUSIONS: The study of the indicators of quality of colonoscopy is feasible and easy to perform in clinical practice, and can be useful for quality assurance programs.

Adolescent↗
PubMed1999

Antioxidant drugs combined with alpha-interferon in chronic hepatitis C not responsive to alpha-interferon alone: a randomized, multicentre study.

OBJECTIVE: After non-response to the initial course of therapy, retreatment with alpha-interferon is not effective. The aim of this study was to ascertain whether the administration of N-acetyl cysteine and vitamin E could increase the response rate to retreatment with alpha-interferon. DESIGN: Prospective, multicentre clinical trial. SETTING: Twelve hospitals in Lombardy, Italy. PARTICIPANTS: 120 consecutive patients affected by biopsy-proven chronic hepatitis C who had been non-responders to a previous course of alpha-interferon, administered at the dosage of 3-6 million units (MU) three times a week (tiw) for 6 months. INTERVENTIONS: The patients were randomly assigned to one of two groups of treatment: group A, natural interferon-alphaN3, 6 or 9 MU tiw, when the body weight was < 60 kg or > or = 60 kg, respectively; group B, the same dosage of natural interferon-alphaN3 in association with oral administration of N-acetyl cysteine 1200 mg/day and vitamin E 600 mg/day. The period of treatment was 6 months in both groups. RESULTS: Neither end-therapy biochemical response nor sustained biochemical response rates were improved by the combination treatment, and in no case was clearance of the virus from serum observed. CONCLUSIONS: In this randomized study carried out on 120 patients with chronic hepatitis C not responsive to alpha-interferon, oral supplementation with N-acetyl cysteine and vitamin E did not improve the poor efficacy of retreatment with alpha-interferon alone.

Acetylcysteine↗
PubMed1999

[Topical beclomethasone dipropionate (BDP) in intestinal inflammatory diseases: the results of a multicentre trial].

The authors assessed the efficacy and tolerability of BDP in an open protocol using rectal enemas and suppositories and in a double-blind protocol vs mesalazine using rectal enemas. A total of 47 patients suffering from ulcerous rectocolitis were enrolled in the study and treated for 42 days while undergoing endoscopic, histologic and clinical controls. In conclusion, the authors affirm that BDP may represent a useful new therapeutic instrument in the treatment of slight to moderately severe forms of inflammatory intestinal disease.

English Abstract↗
PubMed1998

Interferon alfa treatment of HCV RNA carriers with persistently normal transaminase levels: a pilot randomized controlled study.

Most patients with serum hepatitis C virus (HCV) RNA and persistently normal alanine transaminase (ALT) levels show histological features of mild to moderately active chronic hepatitis. Some cirrhosis has also been reported. To assess whether interferon (IFN) treatment led to long-term HCV suppression in these patients, 31 previously untreated patients (15 men, 16 women; mean age, 44 years) with serum HCV RNA, persistently normal ALT levels on at least four consecutive occasions 2 months apart, and histological features of chronic hepatitis (21 mild activity, 10 moderate activity) were randomized to receive 1FN-alpha-2a, 3 MU three times a week for 6 months (n = 16), or no treatment (n = 15). All patients were followed up for at least 6 months after treatment ended. HCV RNA was tested by nested reverse-transcription polymerase chain reaction (RT-PCR) using 5'-untranslated region complementary primers, quantified by branched-DNA assay, and typed by nested RT-PCR testing for the HCV core region. Treated and untreated patients had similar epidemiological, virological, and histological characteristics. At the end of treatment, serum HCV RNA was still detected in 15 patients (94%) and 14 controls (93%). ALT levels flared up in 10 patients receiving IFN (62%) and in 1 control (62% vs. 7%; P < .005, chi2 test). In conclusion, 6 months' treatment with IFN-alpha-2a did not eradicate HCV RNA from serum in carriers with persistently normal ALT levels but caused ALT flare-ups in two thirds of them. Until more is known about the natural history of HCV RNA carriers with normal ALT levels, these patients should not be treated with IFN.

Adult↗
PubMed1998

A simplified urea breath test for the diagnosis of Helicobacter pylori infection using the LARA System. Laser Assisted Ratio Analyzer.

Helicobacter pylori, one of the most prevalent human pathogens, is associated with chronic gastritis, peptic ulcer disease, and possibly gastric cancer and primary gastric lymphoma. The need to treat these patients has necessitated the development of improved methods to diagnose H. pylori infection. We present the preliminary assessment of a 13C-urea breath test (UBT) in which the expired 13CO2 is detected in a rapid, simple, inexpensive way by the LARA (Laser Assisted Ratio Analyzer) System (Alimenterics, Inc., Morris Plains, NJ). Eighty-seven consecutive patients, examined for upper gastrointestinal symptoms, underwent endoscopy. H. pylori infection was established by antral biopsies and a rapid urease test (CLOtest). The UBT was performed between 2 and 24 hours after endoscopy. Of the 84 analyzable patients, 70 were found to be H. pylori-positive either by histology or by CLOtest. All 70 were positive by the LARA UBT, yielding a sensitivity of 100%. Fourteen patients were negative for H. pylori by histology and the CLOtest. Of these, 12 were negative by the LARA UBT and 2 were positive, yielding a specificity of 85.7%; because of the limitations of H. pylori detection by histology or urease assays, however, the specificity of the UBT may have been underestimated. Our study demonstrates the feasibility of a nonradioactive, rapid UBT based on the LARA system and suggests the need for its more detailed evaluation.

Breath Tests↗
PubMed1998

Sorting of phaseolin to the vacuole is saturable and requires a short C-terminal peptide.

Phaseolin, one of the major legume proteins for human nutrition, is a trimeric glycoprotein of the 7S class that accumulates in the protein storage vacuoles of common bean. Phaseolin is cotranslationally introduced into the lumen of the endoplasmic reticulum; from there, it is transported through the Golgi complex to the storage vacuoles. Phaseolin is also transported to the vacuole in vegetative tissues of transgenic plants. By transient and permanent expression in tobacco leaf cells, we show here that vacuolar sorting of phaseolin is saturable and that saturation leads to Golgi-mediated secretion from the cell. A mutated phaseolin, in which the four C-terminal residues (Ala, Phe, Val, and Tyr) were deleted, efficiently formed trimers but was secreted entirely outside of the cells in transgenic tobacco leaves, indicating that the deleted sequence contains information necessary for interactions with the saturable vacuolar sorting machinery. In the apoplast, the secreted phaseolin remained intact; this is similar to what occurs to wild-type phaseolin in bean storage vacuoles, whereas in vegetative vacuoles of transgenic plants, the storage protein is fragmented.

Amino Acid Sequence↗
PubMed1997

Cholera in Lima, Peru, correlates with prior isolation of Vibrio cholerae from the environment.

The authors utilized a recently developed DNA probe technique to obtain quantitative data on occurrence of Vibrio cholerae in samples collected monthly from 12 environmental sites in Lima, Peru, from November 1993 through March 1995. Peak V. cholerae counts ranged from 10(2)/ml to 10(5)/ml, with the highest counts in sewage-contaminated areas and irrigation water. With our methodology, no V. cholerae cases were detected at any site during the winter months of July through October. Counts were detectable in the environment before onset of cholera in the community, with counts at "cleaner" sites upriver correlating significantly with occurrence of community disease 2 and 3 months later. In sites with heavy sewage contamination, V. cholerae could still be detected before the onset of cases in the community; however, in contrast to upriver sites, counts at these latter sites correlated most closely with the number of concurrently occurring cholera cases. These data support a model of cholera seasonality in which initial increases in number of V. cholerae in the environment (possibly triggered by temperature) are followed by onset of illness in the community, with these human cases further amplifying the organism as the epidemic cycle proceeds.

Cholera↗
PubMed1997

Controlled trial of oral 5-aminosalicylic acid for the prevention of early relapse in Crohn's disease.

BACKGROUND: Recent data indicate that 5-aminosalicylic acid (5-ASA) is most effective in preventing relapse of Crohn's disease in patients with a short duration of remission before enrollment. AIM: To evaluate the efficacy of oral 5-ASA treatment, started immediately after achieving steroid-induced remission, in preventing clinical relapses of Crohn's disease. METHODS: Patients with active Crohn's disease, achieving remission on steroids, were randomized to oral 5-ASA 3 g/day or placebo, while steroids were tapered over 6 weeks. The trial was terminated after interim analysis showed a slightly higher relapse rate in the 5-ASA group, and the calculated probability of seeing a statistically significant difference by completing the study was minimal. RESULTS: Final analysis included 117 patients (58 taking 5-ASA and 59 taking placebo; follow-up 9.2 +/- 6.5 months). Cumulative relapse rates at 6 and 12 months were 34% and 58% in 5-ASA patients and 31% and 52% in placebo patients, respectively (rate difference +0.095; 95% CI = -0.085 to +0.274). Subgroups analysis showed that 5-ASA was equally ineffective in patients with ileal, colonic or ileocolonic disease. CONCLUSIONS: Contrary to previous results, in our study early introduction of treatment with oral 5-ASA did not prevent relapse in Crohn's disease patients treated with steroids to induce remission.

Adolescent↗
PubMed1997

Study of the distribution of glycosidic residues in eccrine sweat glands, with special reference to the content of sialic acid.

We used a group of lectins (Con-A, WGA, SBA, DBA, RCA-1, UEA-1), enzymes (neuraminidase digestion) and conventional histochemical techniques (periodic acid-Schiff reaction and reduction-saponification-Schiff reaction) in order to detect the presence of glycoproteins rich in sialic and neuraminic acids in the human eccrine sweat glands. Using both identification systems, our results showed an abundant secretion, rich in C8Oxi-acylated sialic acid.

Adult↗
PubMed1997

Presence and distribution of 5HT-, VIP-, NPY-, and SP-immunoreactive structures in adult mouse lung.

A large number of biologically active substances have been identified and characterised in the respiratory tract of several mammals. These substances (amines and peptides) exert important regulatory influences on respiratory functions, and they act as neurotransmitters/neuromodulators, both being released from nerve terminals as neuroendocrine cells. However, these substances can also have other effects which suggest a paracrine action. Thus, to understand the role of amines and peptides in the lung, it is important to explore their localisation in different species. By using immunocytochemical staining methods we have studied the morphology and distribution of serotonin-, Substance P-, neuropeptide Y- and VIP-like immunoreactivity in the adult mouse lung. Moreover a pretreatment with colchicine, pargyline and 5-hydroxytryptophan as staining enlargement method was made. A widespread distribution of isolated endocrine cells and neuro-epithelial bodies containing 5HT-like immunoreactivity was recorded within the lung. NPY-like immunoreactive nerve fibres were localised in the airway smooth muscle and surrounding the blood vessels. VIP-like immunoreactivity was revealed in single cells as well as in some nerve fibres and ganglia around the blood vessels and in the bronchial smooth muscle. SP-like IR was observed in nerve fibres located in the smooth muscle of the airways, surrounding bronchi and bronchioli but not next to the intrapulmonary blood vessels. Their localisation both in cells and nerve fibres of the respiratory system suggests that they play a role in the regulatory function of the mouse respiratory tract, exerting their influence by endocrine, paracrine, neurosecretory pathways or a combination of all of these.

Animals↗
PubMed1997

Are we correctly using the inhibitors of gastric acid secretion and cytoprotective drugs? Results of a multicentre study.

AIM: To evaluate indications and frequency of prescriptions of pH-modifying and cytoprotective drugs in hospital departments. DESIGN OF THE STUDY: Multicentre cohort transverse relevation. MATERIALS AND METHODS: On a randomly selected day the clinical charts of 3685 inpatients were reviewed by a gastroenterologist and data were collected concerning the drug used, its dosage and indications for the prescription. RESULTS: 26.8% of hospitalized patients were under treatment on the day of the study. Ranitidine was the most frequently prescribed (73.9%). The purpose of treatment was cure of acute disease or symptoms in 27% of cases and prevention of peptic damage in 73%. Fear of development of stress mucosal lesions (28%) and therapy with other drugs (56%) motivated prophylactic treatment in the majority of cases. The examination of clinical charts failed to demonstrate any need for treatment in 51.4% of the patients. Disparities in the frequency of prescription between different departments and hospitals were found. CONCLUSION: Criteria used for prescription of drugs for peptic diseases in hospitalized patients should be strictly monitored to avoid excessive and unmotivated use also in general practice.

Acute Disease↗
PubMed1996

Thyrotropin-like immunoreactivity in human retina: immunoreactive co-localization in ganglion cells and perivascular fibers.

The present immunocytochemical study has demonstrated immunoreactive thyrotropin-like ganglion cell populations as well as perivascular fibers in the human retina by using specific antiserum. Thyrotropin is a pituitary glycopeptide involved in the synthesis and release of thyroid hormones. The existence and functions of peptides in vertebrate retinas are still not well known. Many authors have reported neuropeptide immunoreactivity in the human retina which have had their functions established in the neuroregulatory processes of vision. Moreover, some authors have reported the possibility that the fiber terminal of peptidergic neurons may also be a blood vessel. The appearance of immunoreactive-cells in human retina, e.g. existence of retinal ganglion cells with thyrotropin-like immunoreactivity, indicates the existence of specific mechanisms that would be mediated by these peptides which are located near immunoreactive ganglion cells. We hypothesize that there is an intrinsic mechanism for blood flow control, mediated by retinal ganglion cells which may regulate vessel diameter according to its luminous stimuli. No-one has demonstrated the presence or the functional existence of thyrotropin-like immunoreactive structures in the vertebrate retina, or on the side of the pituitary-thyroid axis. To the best of our knowledge this is the first time that thyrotropin has been immunocytochemically demonstrated in the human retina. Thus, we suggest that thyrotropin acts as a neuromodulator in the human retina, which is implicated in blood flow control.

Animals↗
PubMed1995

The ASGE guidelines for the appropriate use of upper gastrointestinal endoscopy in an open access system.

AIMS: This multicenter and prospective study was aimed at examining the appropriate use of upper gastrointestinal endoscopy in an open access system (primary endoscopy) using the American Society for Gastrointestinal Endoscopy (ASGE) guidelines. We also wished to see whether these guidelines can be easily used in clinical practice. MATERIALS AND METHODS: Three thousand four hundred fourteen upper gastrointestinal endoscopies performed in seven endoscopy units of different size were studied prospectively. The real indication, to be with the guidelines, was determined by the endoscopist before performing the examination, based on a patient's history. RESULTS: Seven hundred eighty-one (23%) endoscopies were "generally not indicated," according to ASGE guidelines, and were distributed as follows: follow-up of duodenal ulcer healing (33%), follow-up of other healed benign diseases (24%), surveillance of gastric atrophy, pernicious anemia, metaplasia, treated achalasia, and prior gastric intervention (14%), diagnosis of dyspepsia considered functional in origin (13%), and uncomplicated heartburn responding to medical therapy (7%). Endoscopies "generally not indicated" accounted for 23% in the bigger endoscopy units, 24% in the average sized units, and 22% in the smaller ones. They accounted for 32% when the examination was prescribed by family doctors, 17% when prescribed by internists, 19% by surgeons, and 14% by gastroenterologists (p < 0.001). Eighty-six (2.5%) endoscopies were done for indications not provided in the guidelines. CONCLUSIONS: This study shows that ASGE guidelines are complete and easy to use and that the rate of inappropriate indications in an open access system can be considerable. They occurred mainly in the follow-up of healed benign disease and were more frequent when the examination was prescribed by the family doctor.

Endoscopy, Gastrointestinal↗