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Biomedical subjects

I Alvarez

Publications and source records attributed to I Alvarez.

At least 73 records · Page 4Linked to original sources
PubMed1997

Relation between histologic subtypes and location of gastric cancer and Helicobacter pylori.

BACKGROUND: Epidemiologic studies have consistently shown an association between Helicobacter pylori infection and gastric cancer, and it is now widely accepted that this organism plays a role in the pathogenesis of this tumor. Nevertheless, there are discrepant results on its relationship with the histologic type and location of gastric cancer within the stomach. The aim of this study was to determine the seroprevalence of H. pylori in a group of gastric cancer patients and the association between H. pylori and specific histologic types of gastric cancer and tumor location within the stomach. METHODS: Systemic IgG antibodies against H. pylori were assayed using an enzyme-linked immunosorbent assay technique in 48 patients (male to female ratio, 31:17; age range, 39-88 years; mean, 69 years) with histologically confirmed gastric cancer and 50 controls (male to female ratio, 33:17; age range, 40-77 years, mean, 64 years). RESULTS: Thirty-one cases of gastric cancer were of the intestinal type, and 12 of the diffuse type; the remaining 5 were unclassified. Thirteen gastric cancers were located in the distal stomach (antrum/pylorus), 12 in the body, and 5 in the proximal stomach (cardia/fundus); the remaining 17 were unclassified because the tumor extended towards more than one location. The overall seroprevalence of H. pylori in patients with gastric cancer and controls was 85.4% and 66%, respectively (P < 0.05). The seroprevalence increased with increasing age in cancer patients, but the difference was not significant. H. pylori seroprevalence among patients with the intestinal type of gastric cancer was higher than in those with the diffuse type (P < 0.05). The prevalence of H. pylori infection was higher among patients with the cancer located distally than in those with the cancer located proximally (P < 0.05). CONCLUSIONS: H. pylori seroprevalence was higher in gastric cancer patients than in controls. The prevalence of H. pylori infection in intestinal-type gastric cancer was clearly higher than in the diffuse type and in the control group. An association was found between H. pylori infection and tumors located distally (antrum/pylorus).

Adenocarcinoma↗
PubMed1997

Helicobacter pylori eradication for the treatment of low-grade gastric MALT lymphoma: follow-up together with sequential molecular studies.

BACKGROUND: Helicobacter pylori infection is associated with low-grade gastric MALT lymphoma, and available data support that the eradication of the H. pylori can cause histological regression of the lymphoma. PATIENTS AND METHODS: Nine patients with low-grade gastric MALT lymphoma were treated with amoxicillin, metronidazole, and omeprazole for 14 days in a prospective study. Patients were followed up with sequential endoscopy, mapping gastric biopsies, and molecular studies with PCR amplification of the IgH gene in order to assess the response to H. pylori eradication and the evolution of the histological molecular responses. RESULTS: H. pylori was eradicated in all patients and reinfections were not demonstrated. After H. pylori eradication treatment, the lymphoma regressed both endoscopically and histologically in eight of the nine patients (88.8%). In four of the eight histologically cured patients, no clonal band was detected by PCR; in the remaining four patients; PCR identified a clonal band, which disappeared in all patients after a mean of 12 +/- 4 months. No clonal band was detected by the PCR analysis in any of the eight patients with histological regression after a median of 7 +/- 6 months (range 1-20). The seven followed-up patients have a persistent clinical and histological remission after a median of 14 +/- 5 months. CONCLUSIONS: (1) Low-grade gastric MALT lymphoma can be histologically cured with eradication therapy for H. pylori. (2) After histological regression, PCR amplification of the IgH gene can identify an eventually persisting clonal population. (3) Sequential histological and molecular studies are essential for the assessment of the evolution of the lymphoma. (4) The clonal population tends to disappear, but its disappearance may be delayed for months. (5) Patients with histological regression but with a persistent clonal band should not be treated unless the lymphoma can be histologically demonstrated. All these observations suggest that gastric lymphoma can be effectively cured, but the ultimate fate of these patients is unknown until long-term follow-up studies are available.

Aged↗
PubMed1997

[Tuberous sclerosis. Description of a family study].

We present tuberous sclerosis affecting all the members of a family, now and for three consecutive generations (probably four). A fortuitous study of cutaneous disease in one member led to diagnosis in all of them. A systematic study detected important visceral implication in all cases, mainly neurological, despite the fact only one of then showed related symptoms. We discuss the epidemiological and diagnostic aspects of an illness, which is widely underdiagnosed even today, despite the fact that detection is by sight.

Adolescent↗
PubMed1996

MYC amplification in squamous cell carcinomas of the head and neck.

OBJECTIVES: To establish the frequency of MYC amplification in squamous cell carcinoma (SCC) of the head and neck to evaluate its correlation with clinicopathologic variables that are used in clinical practice. DESIGN: Cohort analytic study. SETTING: University Hospital. PATIENTS: Fifty-nine consecutive patients with SCC of the head and neck. INTERVENTION: Oncologic surgery. MAIN OUTCOME MEASURES: The MYC copy number in tumor samples was estimated with the polymerase chain reaction. The presence or absence of amplification was correlated with the anatomic site, T stage, nodal involvement, pathologic grade, recurrence, distant metastases, and survival. RESULTS: Six SCC specimens (11%) showed MYC amplification. A highly statistical correlation between MYC amplification and T stage was noted (P < .005). Amplification was also significantly correlated with a hypopharyngeal primary site (P < .05). No correlation among amplification status, nodal involvement, pathologic grade, relapse, metastases, and survival was observed. CONCLUSIONS: Amplification of MYC is associated with advanced primary tumors, and it appears to be a late event in the tumorigenesis of SCCS of the head and neck. However, there is no correlation between MYC amplification and prognosis.

Adult↗
PubMed1996

Amplification of ERBB oncogenes in squamous cell carcinomas of the head and neck.

The activation of ERBB oncogenes has been described in various human tumours, including squamous cell carcinomas of the head and neck (SCCHN), and, in some of them, it has been correlated with a poor prognosis. Tissue samples from 59 patients with SCCHN were studied. After DNA extraction, the ERBB1, ERBB2 and ERBB3 copy number in tumour samples was estimated with the polymerase chain reaction (PCR) method. The PCR products were analysed by agarose gel electrophoresis and quantified by image analysis techniques. 9 (15%) cases presented with ERBB1 amplification, which was correlated with lymph node involvement (P = 0.04), poorly differentiated tumours (P = 0.03) and a hypopharyngeal primary site (P = 0.035). No correlation among amplification status, recurrence, metastases and survival was observed, although this may be due to the small number of patients in the amplified group. None of the 59 cases presented amplification of ERBB2 and ERBB3 oncogenes.

Adult↗
PubMed1995

Effects of a novel 5-HT1A receptor agonist, E4424, on gastric adherent mucus levels following restraint stress in rats.

Several novel arylpiperazine serotonin 1A receptor agonists, developed as anxiolytics, have antisecretory and gastroprotective effects in rats. E4424 (2-¿4-[4-(4-chloropyrazol-1-yl)butyl]-1-piperazinyl ¿pyrimidine; Lesopitron dihydrochloride), has potent anti-gastric secretory and antiulcer effects. Preliminary data indicated an enhancing effect of E4424 on gastric mucus that may underlie its gastroprotective actions. We therefore tested the effects of acute and chronic administration of E4424 and of a reference 5-HT1A receptor agonist, 8-OHDPAT [8-hydroxy-2-(di-n-propylamino)tetralin], on gastric mucus levels in rats subjected to cold-restraint stress, a procedure associated with depletion of gastric mucus and the development of mucosal injury. Acute oral administration of E4424 increased adherent mucus levels by 12%, 11%, and 13%, relative to controls. Chronic E4424 significantly increased gastric mucus relative to controls (69% increase). Acute oral treatment with 8-OHDPAT did not affect gastric mucus level. Acute intraperitoneal 8-OHDPAT slightly increased mucus levels. Chronic twice per day 8-OHDPAT did not affect mucus levels; however, chronic once per day treatment with 8-OHDPAT significantly elevated gastric mucus levels at the highest doses used. For E4424, there is a strong correlation between reduction of gastric mucosal injury and increase in gastric mucus level, suggesting that the action of E4424 on glandular mucus levels is an important mechanism underlying its gastroprotective effects.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Some novel 5-hydroxytryptamine1A (5-HT1A) receptor agonists reduce gastric acid and pepsin secretion, reduce experimental gastric mucosal injury and enhance gastric mucus in rats.

The present studies examined the actions of a series of novel arylpiperazine 5-hydroxytryptamine1A (5-HT1A) agonists, developed originally for anxiolytic efficacy, in several models of gastric secretion and experimental gastric mucosal injury. These models included conscious gastric acid secretion, pylorus ligation (gastric acid and pepsin secretion), stress-induced gastric mucosal injury, ethanol-induced gastric mucosal damage and gastric adherent mucus levels. 2-(4-[4-(4-Nitropyrazol-1- yl)butyl]-1-piperazinyl)pyrimidine (E4414) and 2-(4-[4-(4-chloropyrazol-1-yl)butyl]-1-piperazinyl)pyrimidine dihydrochloride (E4424) significantly inhibited gastric acid secretion in conscious as well as in pylorus-ligated rats. Both compounds also significantly reduced pepsin secretion in pylorus-ligated animals. E4414 and E4424 significantly reduced both stress-induced and ethanol-induced gastric mucosal injury, and both compounds significantly maintained gastric adherent mucus levels in rats subjected to stress. The antisecretory and gastroprotective actions of E4414 and E4424 were of significantly greater magnitude than those of the reference 5-HT1A agonists, buspirone and 8-hydroxy-2-(di-n- propylamino)tetralin. These results suggest that some novel 5-HT1A agonists exert gastroprotection not only through reduction of aggressive elements in the gut (acid and pepsin secretion) but also through enhancement of defensive gastrointestinal factors such as adherent mucus.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Genetic similarity and mate selection in Uruguay.

It has been suggested that average genetic similarity, as assessed by blood genetic markers, could influence mate choice in humans. In the present study, average genetic similarity was assessed in 183 couples submitting to paternity determinations in relation to six blood group systems and three HLA loci. Couples in which the putative father was excluded were compared with those in which such exclusion did not occur, and real couples were compared to random pairs. The differences were all statistically nonsignificant. Possible reasons for the different results found in the previous sample and in the present study are considered.

Adult↗
PubMed1993

Pseudotumoral appearance of cytomegalovirus esophagitis and gastritis in AIDS patients.

Cytomegalovirus (CMV) is frequently isolated from patients with acquired immunodeficiency syndrome (AIDS), and often causes disseminated disease. Gastrointestinal CMV involvement is recognized with increased frequency in AIDS patients. It can involve the entire alimentary tract and usually produces mucosal ulceration. Pseudotumoral lesions develop very infrequently. We report two unusual detailed cases of biopsy-proven CMV esophagitis and gastritis resembling carcinoma, in patients with human immunodeficiency virus infection. In AIDS patients, the gastrointestinal CMV involvement could show pseudotumoral appearance.

AIDS-Related Opportunistic Infections↗
PubMed1993

Sino-nasal adenocarcinoma: epidemiological and clinico-pathological study of 34 cases.

Thirty-four cases of sino-nasal adenocarcinoma treated between 1976 and 1992 are presented. The purpose of this work is the epidemiological analysis of this disease and to put forward a classification of the lesions according to their degree of differentiation, based on the histopathological examination of 29 tumors. The risk increase of having a sino-nasal neoplasia was significant in the population exposed to wood dust in their working environment--896 times greater (540 in the male population) for adenocarcinoma and 20 times greater for squamous-cell adenocarcinoma. The proposed histopathological classification divides these lesions according to their degree of differentiation. In this series 23 well-differentiated cases were found, three moderately differentiated and three colloid-type. The five-year determinate survival of this series was 30%. The tumor stage (especially intracranial involvement) was the only significant clinico-pathological parameter that impaired the survival.

Adenocarcinoma↗
PubMed1992

Morphological changes in long bone development in fetal akinesia deformation sequence: an experimental study in curarized rat fetuses.

In order to investigate the transverse growth of the long bones during intrauterine development in the fetal akinesia deformation sequence (FADS), we studied curarized rat fetuses. Curarization was performed by daily subcutaneous administration of D-Tubocurarine from day 17 of gestation until term. Experimental fetuses were compared with a sham-operated control group. The total area and perimeter, the absolute and relative amount of periosteum and bone trabeculae, the major and minor axes, and the elongation factor were measured from histological cross-sections of the femoral metaphysis and diaphysis using an IBAS 1 image analysis system. Curarized rat fetuses showed growth retardation, a short umbilical cord, and multiple articular contractures, a phenotype consistent with FADS. Alterations in femoral shape and transverse growth that affected the diaphysis were noted in these fetuses. These included a decrease of total cross-section area and reduction of the absolute and relative amounts of bone trabeculae with marked thinning of the periosteum. Femoral cross-sections was rounder than controls. These results evidenced an impairment of the membraneous (periosteal) ossification of long bones produced by immobilization and/or decrease of muscular strength, and support our previous clinical findings of bone hypoplasia and osteopenia in FADS.

Animals↗
PubMed1992

Long bone development in extrinsic fetal akinesia: an experimental study in rat fetuses subjected to oligohydramnios.

The transverse growth of long bones during intrauterine development was studied in rat fetuses subjected to experimental oligohydramnios in order to determine whether the skeletal changes, if any, in extrinsic fetal akinesia were similar to those observed in curarized rat fetuses with the fetal akinesia deformation sequence. Oligohydramnios was induced by daily extraction of amniotic fluid from day 17 of gestation until term. Experimental fetuses were compared with a sham-operated control group. The total area and perimeter, the absolute and relative amount of periosteum and bone trabeculae, the major and minor axes, and the elongation factor were measured in histological cross sections of the femoral metaphysis and diaphysis with an IBAS 1 image analysis system. Rat fetuses in the experimental group showed multiple articular contractures, redundant skin, and lung hypoplasia, a phenotype consistent with the oligohydramnios sequence. No alterations in femoral shape and transverse growth of the metaphysis and diaphysis were noted in these fetuses. These results suggest that the main mechanical factor related to fetal bone modeling is muscular strength, while motion would be mainly involved in fetal joint development.

Animals↗
PubMed1992

Control of neck nodes in squamous cell carcinoma of the head and neck by radiotherapy: prognostic factors.

313 patients with cervical metastases from a squamous carcinoma of the head and neck treated with radiotherapy, were studied by means of a multivariant analysis in order to determine the prognostic factors for cure. These were: lymph node response to irradiation (P = 0.0000), size of node (P = 0.0000), radiotherapy dose (P = 0.0037), condition of the primary (controlled vs non-controlled) (P = 0.0015), recurrent cervical metastases post-surgery (P = 0.0286).

Adolescent↗
PubMed1991

Radioimmunolocalization of colorectal carcinoma. A correlation among RIL results, surgical findings, serum tumor marker levels and the presence of CEA and CA 19.9 in tumor tissue: the experience of the Hospital de la Santa Creu i Sant Pau.

We report a prospective study in two groups of colorectal cancer patients carried out by radio-immunolocalization (RIL) with F(ab') fragments of monoclonal antibodies against CEA and CA 19.9 labeled with 131-I. Twenty-two patients were studied before radical surgery and 12 patients after initial surgery, when progressive increase in CEA was registered. Scintigraphic images obtained in vivo in RIL studies were compared with scintigraphic images of the corresponding surgical specimens. Results were compared with known serum marker levels and with the presence and localization of markers in the excised specimens. RIL images correctly identified 13 of 23 (52%) primary tumors, with only one false positive image. Scintigraphy of surgical specimens correlated with RIL findings in 14 of 19 cases (74%). Four specimens which showed antibody uptake had not been visualized preoperatively in the RIL study. Two of them were retrovesical and were obscured by residual activity in the bladder. Nine of 13 (64%) patients with at least one elevated tumor marker were imaged. Staining pattern or intensity of antigen staining in the specimens did not correlate with RIL findings. Recurrent disease was confirmed by laparotomy or other exploration in 10 of the 12 patients with progressive CEA elevation during follow-up. Spontaneous normalization of CEA levels was observed in the remaining 2 patients. RIL studies were positive in 7 of the 10 patients with confirmed recurrent disease. Of the 3 false negative patients 2 had liver metastases and one developed clinical lung, bone and adrenal metastases 11 months later. No false positive studies were observed in this group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1990

[Clinical application of radioimmunolocalization in colorectal cancer].

We present preliminary results of radioimmunolocalization (RIL) of colorectal cancer with 131I labelled F(ab')2 fragments from monoclonal anti CEA and anti CA 19.9 antibodies in 22 patients with colorectal cancer and in one patient with metastases of unknown origin and high CEA value. Positive images were obtained in 7 of 11 primary tumors from 10 patients evaluated preoperatively; in 2 of 3 recurrences; in 9 of 12 metastatic localizations and in the unknown primary tumor localized, finally in the cecum. One local recurrence was not detected by any diagnostic methods, but RIL. There was not false-positive images. Therefore, RIL appears as a promising method for the diagnosis and follow-up of colorectal cancer.

Antigens, Tumor-Associated, Carbohydrate↗