Search PubMed⌕ Search

Biomedical subjects

C Rubio

Publications and source records attributed to C Rubio.

At least 109 records · Page 6Linked to original sources
PubMed1994

Histogenesis of small colonic adenocarcinomas.

It has been claimed that in order to identify the type of mucosal lesion which precedes colonic adenocarcinoma only those tumours measuring < or = 1 mm in diameter should be considered. The review of the English literature indicates that only 35 colorectal adenocarcinomas measuring < or = 1 cm in diameter have been so far reported. From the three cases of colonic adenocarcinoma measuring 8 mm or less in diameter presented here, one adenocarcinoma originated in a flat adenoma, the second in an exophytic tubular adenoma, and the third showed no adenomatous component. It would thus appear that colonic adenocarcinomas can originate not only from exophytic adenomas or from flat adenomas but also from apparently nonadenomatous flat mucosa.

Adenocarcinoma↗
PubMed1994

Ear tumours induced by experimental carcinogenesis in the rat: excision prevents early death.

1,2-dimethylhydrazine (DMH) is widely used to induce colorectal tumours in rodents. Some of the animals develop ear as well as colorectal tumours. Rats with large, ulcerated ear tumours are usually sacrificed before the completion of the experiment. In this experiment, fourty-six male Spraque-Dawley rats were injected with 1,2-dimethylhydrazine (21 mg/kg body weight) once a week for 27 weeks to study the histogenesis of colorectal carcinoma. Thirty-six developed ear tumours. Fourteen of the 36 tumours were larger than 2 cm in diameter. These developed between 20-26 weeks and were surgically excised 1-5 weeks later. Four rats died postoperatively. The surgical removal of large ear tumours permitted the completion of the large bowel experiment on schedule (i.e. 27 weeks) in 10 (28%) of the 36 rats with ear tumours.

1,2-Dimethylhydrazine↗
PubMed1994

DNA aneuploidy and histologic dysplasia in long-standing ulcerative colitis. A 10-year follow-up study.

PURPOSE: This study was designed to assess the presence of DNA aneuploidy and mucosal dysplasia, respectively, in 63 patients with long-standing ulcerative colitis. METHODS: The DNA content in colonic biopsies was investigated, using a flow cytometry method, and compared with conventional histology. Patients were subsequently followed each or every second year with colonoscopy and histology. A second flow cytometry examination to monitor the DNA pattern was performed after 10 years. RESULTS: Initially, abnormal DNA pattern (i.e., aneuploidy) was found in 13/63 (21 percent) patients. The colonic mucosa was flat in 10, polypoid in 1, and tumor infiltrated in 2. Eight of the 10 aneuploid cases with a flat mucosa showed no signs of histologic dysplasia. In one of two cases with simultaneous aneuploidy and low-grade dysplasia, a carcinoma Dukes B was found at subsequent colectomy. On the other hand, dysplasia (one low grade and one high grade) without aneuploidy was found in two patients at the initial investigation. After 10 years, 13 had been colectomized, 11 had died (7 noncolitis related), and 3 were lost to follow-up. In the remaining 36 living patients with intact colorectum, no case of histologic dysplasia, but 6 cases of DNA aneuploidy were discovered at the initial investigation. Of the six aneuploid cases, one was later reclassified as diploid and one consisted of an aneuploid adenomatous polyp (removed by polypectomy). At follow-up 10 years later, 3/4 of the other aneuploid cases showed repeated abnormal DNA pattern, now together with histologic low-grade dysplasia (in flat colon mucosa). The 30 patients with initially normal DNA patterns were all still diploid at re-examination 10 years later, but 2 now revealed low-grade dysplasia histologically. CONCLUSIONS: DNA aneuploidy in chronic ulcerative colitis seems to be stable and it may precede histologic dysplasia by many years. It appears to be an additional marker for detecting neoplastic transformation in ulcerative colitis.

Adenocarcinoma↗
PubMed1994

Flat adenoma-adenocarcinoma sequence in the colon of rats.

PURPOSE: As there is an increased awareness of the existence of a "flat adenoma-adenocarcinoma sequence" in the colonic mucosa of human subjects, the aims of the study were to assess whether flat colonic adenocarcinomas in rats are also preceded by flat adenomas, as is reported in humans, and to determine the frequency of flat lesions compared with exophytic lesions in the colon of rats. METHOD: The colonotropic carcinogen 1,2-dimethylhydrazine was injected subcutaneously in 300 Sprague-Dawley rats for 27 weeks. RESULTS: A total of 358 tumors developed in 278 of the 300 rats. Of the 60 adenomas found at histology, 25 percent were flat adenomas. Of the 298 adenocarcinomas, 12.7 percent had originated in a flat adenoma. Of the 180 colonic neoplasias (adenomas or adenocarcinomas), 29.4 percent were flat neoplasias (flat adenomas or adenocarcinomas arising in a flat adenoma), and the remaining 70.6 percent were exophytic neoplasias (tubulo or villous adenomas or adenocarcinomas arising in exophytic adenomas). From the 298 colonic adenocarcinomas, 1 was a intramucosal adenocarcinoma, 87 were overt adenocarcinomas, and 90 were lymphoid-associated carcinomas; in those 298 adenocarcinomas, no preneoplastic lesion could be recorded. In 208 animals, biopsies were taken from macroscopically visible colonic lesions, and, in the remaining 70 animals, the entire colon was processed for histologic examination. Flat adenomas were found in 3.8 percent of the 208 biopsy specimens and in 10 percent of the 70 colectomy specimens. Further, of the 40 adenomas found in biopsy specimens, 20 percent were flat adenomas, and, of the 20 adenomas found in colectomy specimens, 35 percent were flat adenomas. CONCLUSIONS: The study reported herein indicates the existence of a "flat adenoma-adenocarcinoma sequence" in the colonic mucosa of Sprague-Dawley rats. The flat lesions of the colon constituted approximately one-third of the total neoplastic lesions seen in the rat following injections of 1,2-dimethylhydrazine. More flat adenomas were detected at histologic examination of the entire colon than in biopsies obtained from the macroscopically visible colonic lesions. Consequently, flat adenomas may be overlooked by naked-eye examination.

1,2-Dimethylhydrazine↗
PubMed1994

Herpes simplex viremia: report of eight pediatric cases and review of the literature.

Bloodstream infection due to herpes simplex virus (HSV) is rare in the immunocompetent host but may be important in the pathogenesis of disseminated HSV infection in the immunocompromised patient. Using a simple blood-culture method, we detected herpes simplex viremia in eight immunologically compromised or immature children: two neonates, two oncology patients, and four transplant recipients. Only two patients initially exhibited evidence of mucocutaneous HSV infection. Blood was cultured for HSV because of perinatal exposure, for routine surveillance, or for the evaluation of fever, esophagitis, or oral lesions in immunocompromised patients. In five cases HSV was recovered only from the blood; in two other instances blood cultures for HSV were the first positive cultures. The time required for the detection of HSV by blood culture ranged from 1 day to 12 days. In one case viremia was transient and cleared without specific therapy. The other seven cases were treated with intravenous acyclovir; in four of these cases, therapy was initiated because of the positive blood culture. The detection of HSV in blood may promote early initiation of antiviral therapy and thereby improve prognosis.

Antiviral Agents↗
PubMed1994

The significance of mucosal staining for the endoscopic diagnosis of chronic esophagitis as assessed in biopsy findings.

A total of 115 patients with clinical signs of esophagitis were examined by endoscopy and mucosal biopsy combined with Lugol solution. Overall, 175 mucosal areas (105 stained and 70 unstained) were subjected to histopathological examination. The correlation between the staining properties of the esophageal mucosa and the histopathological diagnosis resulted in a diagnostic sensitivity of 51.9%, a specificity of 70.2%, a positive predictive value of 60.0% and a negative predictive value of 62.9% for Lugol combined endoscopy. Lugol combined endoscopy did not appear to result in any improvement in the diagnosis or staging of reflux esophagitis in our study.

Adult↗
PubMed1993

Late seroconversion and high chronicity rate of hepatitis C virus infection in patients with hematologic disorders.

BACKGROUND: Patients with hematologic disorders requiring repeated blood and platelet transfusions are at high risk for development of post-transfusion non-A, non-B hepatitis. PATIENTS AND METHODS: Fifty-five patients with hematologic diseases and post-transfusion non-A, non-B hepatitis were studied. Sera were assayed for hepatitis C virus (HCV) antibodies with a second-generation enzyme-linked immunoassay. Sera from 40 patients were examined for the presence of HCV RNA with a nested PCR method. RESULTS: The clinical picture of acute non-A, non-B hepatitis did not differ from that described in other patient groups: however, progression to chronic hepatitis was very common (95%). Thirty-eight (95%) of 40 patients, whose sera were analysed both serologically and for the presence of HCV RNA had verified HCV infections. In some patients time to seroconversion was prolonged, up to more than 14 months. Seventeen patients with resistant or relapsed acute leukemia were treated with combination chemotherapy during the acute or chronic phase of hepatitis. Suppression of the inflammatory activity as reflected by a decrease of serum aminotransferase levels was recorded during the subsequent pancytopenic period. CONCLUSIONS: Hepatitis C has a high chronicity rate in patients with hematologic disorders which parallels the situation of hepatitis B in the immunocompromised host. Furthermore, like the situation in hepatitis B, the hosts' immune response to infection seems to be involved in the pathogenesis of liver injury. Time to seroconversion may be prolonged and detection of HCV RNA is therefore important for diagnosis.

Adolescent↗
PubMed1993

Helicobacter pylori in 205 consecutive endoscopy patients.

The presence of Helicobacter pylori in the gastric, antral mucosa of 205 consecutive, unselected gastroscopy patients was investigated by 1-3 biopsies for urea broth test and culture, 1 biopsy for histological examination and 1 blood sample for serology by ELISA. Overall, 41% were positive for H. pylori by culture, 32% by urea broth test, 24% by histological staining and 67%, 56% and 49% for the 3 cut-off limits applied to serology. Culture and serology indicated the presence of H. pylori in 79-92% of the 14 cases with duodenal ulcer, in 59-82% of the 28 cases with gastric ulcers, in 45-71% of the 51 cases with endoscopic gastritis and in 33-69% of 13 cases with oesophagitis. In patients with histological antritis, H. pylori was identified by culture in 71% (60/84), by serology in 95%, 88% and 81% with the different cut-off limits. The sensitivity of serology ranged from 99-78% depending on the cut-off limits and the specificity from 78-100% against all parameters combined. These results suggest that serology is a useful screening method for the presence of H. pylori. Future antibiotic treatment studies are required to evaluate the clinical relevance of H. pylori in gastrointestinal disease and to investigate the possibility to monitor eradication by serology.

Adolescent↗
PubMed1992

Colectomy-proctomucosectomy with S-pouch: operative procedures, complications, and functional outcome in 69 consecutive patients.

Sixty-nine patients were operated upon in a three-stage procedure. Early complications occurred in 29 percent after colectomy-ileostomy, in 25 percent after proctomucosectomy with ileoanal anastomosis and loop ileostomy, and in 9 percent after closure of loop ileostomy. Only three of these were considered serious. Seventy-one percent of the patients were readmitted into the hospital between the three operations or after the last one. Total hospital stay was 49 days (median); the range was 20 to 345 days. Reconstruction of the reservoir was performed in four patients owing to defecation problems, with satisfying functional results in two patients, while two emptied by catheter. There was no postoperative mortality or pelvic sepsis, and no pouches were excised. Ileostomy was re-established in two patients. At histopathologic re-evaluation of colectomy specimens, the diagnosis was changed from ulcerative colitis to Crohn's disease in three patients and to indeterminate colitis in five. Median follow-up was 4.3 years. Continent anal defecation without ileostomy was achieved in 67 patients (97 percent), with 4.1 bowel movements per day and 0.6 per night. Perfect continence was achieved in 55 percent in the daytime and in 43 percent at night. The low rate of reservoir-threatening complications is attributed to the three-stage procedure and the technical details in the surgical procedures.

Adolescent↗
PubMed1991

Ischemic colitis of the cecum after renal transplantation masquerading as malignant disease.

Fourteen years after kidney transplantation and following protracted rejection of the transplant, a patient developed abdominal pain, fever, and leukocytosis. Ultrasound demonstrated a pericolic abscess, and barium enema a deformity of the ascending colon suggesting malignant growth. Colonoscopy showed ulcerative and necrotic lesions of the cecum, and colonic carcinoma was suspected. At surgery, a granulomatous inflammatory reaction with fibrosis involving the kidney transplant and cecum was found. Histological examination revealed ulcerations secondary to ischemic colitis, but no malignancy. Thus, ischemic colitis should be ruled out in cases with a presumptive diagnosis of colonic malignancy at x-ray or endoscopy.

Adult↗
PubMed1991

Regional influences on the physical properties of T cell membranes.

Differences in the composition of membrane lipids are well documented between cells from distinct tissues. These differences may be manifested by changes in the motional freedom or fluidity of lipid molecules within plasma membranes and may predispose to alterations in cellular function. Regional influences on immune function have been implied by the finding that thymic-derived cells from murine spleen and lymph nodes are differentially responsive to antigen priming. The possibility that microenvironment also shapes the physical properties of T lymphocyte membranes has not been explored and is the focus of this study. Using mice as the experimental model, differences were found in fluidity and in the resting level of intracellular free-ionized Ca2+ between splenic and lymph node T cells from immunologically normal mice and from autoimmune-prone MRL-lpr/lpr mice. The results indicate that T cells are more heterogeneous than previously recognized and suggest a potential role for microenvironment in determining immune responsiveness.

Animals↗
PubMed1991

A possible error in the interpretation of gastric carcinoma.

Isolated clusters of pyloric cells having homogeneous, eosinophilic (i.e., "glassy") cytoplasm were present in 6 (18.2%) of 33 consecutive gastrectomy specimens. Clusters with "glassy" cells displayed either a glandular arrangement or appeared as cohesive clusters. Cohesive clusters could be misinterpreted as signet-ring cell adenocarcinoma. However, remnants of the apical mucous secretion from the "ordinary" pyloric cells, the nuclei usually near the free border of the cells, as well as the negative reaction in the "glassy" cytoplasm for neutral and acid mucins, helped to differentiate them from signet-ring adenocarcinoma cells.

Adenocarcinoma↗
PubMed1991

Twenty-four hour fasting increases endotoxin lethality in the rat.

The effect of 24 h food deprivation on endotoxin (ET) lethality in SpD rats was studied. Fed and fasted animals received either 6 h i.v. infusions or i.p. boluses of ET at low, intermediate and high doses, and survival for seven days observed. Fasting was associated with 208-240% greater mortality when ET was infused i.v., and 87-200% when given i.p. ET doses LD10-LD80 gave a linear relationship with mortality. In non-fasted control rats liver glycogen content reduced by 1.28 mumols/min/g dry liver wt over the first post-prandial six hours, and increased by 65-99% in a dose dependent manner after ET (p less than 0.01). Evidence was also obtained relating both liver damage (assessed blind by histopathological scoring) and leucopenia with endotoxin dose, results which were modified by nutritional status. The evidence supports the role of liver glycogen as a protective substrate resource in endotoxic shock.

Animals↗
PubMed1991

[Cardiovascular risk factors in the working population of Alicante].

The aim of the present study was to evaluate the prevalence of certain cardiovascular risk factors in the population of Asepeyo-Elche. The study sample was a working population of 697 persons (71.8% males and 28.2% females) with ages ranging from 15 to 65 years (mean age 34.7 +/- 13.2 years), seen during the first 6 months of 1990 in the health care center of Asepeyo-Elche. The evaluated cardiovascular risk factors and their prevalence rates were: hypertension (14.2%), hypercholesterolemia (18.5%), smoking (52.5%), hyperglycemia (3.5%), obesity (28.2%) and sedentariness (80.3%). We conclude that in our working population the prevalence rates of some cardiovascular risk factors are high and that intervention programs to modify the diet and lifestyle are mandatory to prevent the pathogenetic consequences of these factors.

Age Factors↗