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Biomedical subjects

L Herrera

Publications and source records attributed to L Herrera.

198 records · Page 11Linked to original sources
PubMed1979

[Survival of Cochliobolus miyabeanus in the soil (author's transl)].

Survival of C. miyabeanus in irrigated soils of rice fields was higher in infected rice straw (70 days) than in infected rice leaves (40 days). The fungus survived longer in soil depth of 30 cm as in a depth of 15 cm. Between the survival of the fungus and the destruction of infected plant material exist a correlation. In infected rice seeds survived the fungus longer by 5--8 degrees C than by 26--33 degrees C.

Ascomycota↗
PubMed1976

Selection of auxotrophic mutants in Saccharomyces cerebisiae by a snail enzyme digestion method.

Yeast cells in the stationary phase of growth are relatively resistant to snail enzyme digestion. This resistance was shown to decrease abruptly in the course of only 3-5 duplications, when stationary cells were allowed to grow in a fresh medium. The selective digestion of growing prototrophs from a mutagenized culture in minimal medium by snail enzyme was applied to increase the proportion of auxotrophs which remained relatively resistant.

Cell Division↗
PubMedDate not supplied

Small bowel tumors: an overview.

Tumors of the small bowel, both benign and malignant, are relatively uncommon and often present a diagnostic challenge as their symptoms are often vague. This review article outlines the incidence, presentation, diagnosis, and management of small bowel tumors.

Adenocarcinoma↗
PubMedDate not supplied

Synanthropic rodent reservoirs of Trypanosoma (Schizotrypanum) cruzi in the valley of Caracas, Venezuela.

Direct blood examination and xenodiagnosis of 47 synanthropic rodents (Rattus rattus, R. norvegicus, Mus musculus) captured in the valley of Caracas, Venezuela, revealed trypanosomal infections in 12 R. rattus, 10 with T. lewisi and 2 with T. cruzi. Of the latter the course of parasitemia, the pleomorphism of the bloodstream trypomastigotes, tissue in naturally and experimentally infected rats and mice, host mortality, morphology of fecal parasites in Rhodnius prolixus used for xenodiagnosis, and infectivity of the bug feces for NMRI mice, were all characteristic of Trypanosoma (Schizotrypanum) cruzi. One rat, with a patent parasitemia, had numerous nests of amastigotes in cardiac muscle and moderate parasitism of the smooth muscle of the duodenum and of skeletal muscle. Mice inoculated with fecal flagellates from the bugs had moderate tissue tropism in the same organs and also in the colon and pancreas. The possible role of R. rattus in the establishment of foci of Chagas' disease in Caracas is discussed.

Animals↗
PubMedDate not supplied

Crypt cell antigens (CCA): new carbohydrate markers for human colon cancer cells.

A panel of monoclonal antibodies produced against surface membrane components of the human colon tumor cell line Caco-2 was found to define oncofetal crypt cell antigens (CCA) expressed by fetal intestinal cells, adult small intestinal crypt cells, and human and rat colonic adenocarcinomas. The epitopes recognized by these antibodies have been identified as O-linked oligosaccharide chains associated with specific glycoproteins in cultured intestinal cells and in colon tumors in vivo. Analysis of a large group of normal and diseased human intestinal specimens has demonstrated a marked heterogeneity in CCA expression which correlated with the degree of organization of the tumor cells in the tissue, suggesting that the CCA represent useful histological and clinical markers for colon cancer.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Estimation of infant and child mortality in the eastern provinces of Cuba].

An estimate of infant and child mortality in the eastern provinces of Cuba is presented using the Brass method as adapted by Trussell. "Estimations by urban and rural zones are also performed within the provinces studied, and results are compared with those possible to obtain by continuous statistics. Results obtained show that in the eastern [part] of the country Holguin and Guantanamo are the provinces with highest infantile mortality rates, and the lowest rates correspond to Granma, followed by Santiago de Cuba." (SUMMARY IN ENG AND FRE)

Americas↗
PubMedDate not supplied

[Laparoscopic cholecystectomy. Analysis of 50 cases].

Biliary lithiasis is considered a significant health problem. Traditionally open cholecystectomy has been considered the gold standard procedure for symptomatic cholecystitis. Laparoscopic cholecystectomy has recently emerged as an alternative, but its usefulness in community hospitals is still being evaluated. Herein we reported our experience in 50 patients treated for 7 months (August of 1991, to February of 1992) by laparoscopic cholecystectomy. It has been necessary to convert one case into an open surgery. There has been no mortality. Seven patients developed right shoulder pain postoperative, it was controlled with minor non addictive analgesics. One had umbilical hematoma, another patient had a superficial phlebitis, and another one developed urinary retention. 43 patients (86%) had had 12 to 24 h hospital stancy, and were back to their normal activities in 7 days; during a 7 months follow-up no complications have been reported. We concluded that laparoscopic cholecystectomy is a safe procedure and can be done by the average general surgeon in community hospitals in a selected patient population. However, we strongly support a continuous monitoring of a protocol for patient management for record-keeping-purposes and as an educational tool.

Adolescent↗
PubMedDate not supplied

[Pancreatic resections at general hospitals in Torreon, Coahuila].

A retrospective study of nine patients with pancreato-biliary neoplasias were operated in several general hospitals in Torreon, Mexico. Six had pancreatic adenocarcinoma, two ampullary carcinoma and one with common bile duct benign adenoma. We had a morbidity of 55% (5/9); three cases with pancreatic fistula (resolved with nutritional support and general measures) two had obstruction of gastricyeyuno anastomosis (one required surgical management). One patient (11%) died of massive pulmonary embolism. We have now the possibility to perform an earlier diagnosis with update invasive and non invasive diagnostic studies such ERCP, computed tomography and angiography. We are proud to have in our hospitals, intensive care units and well trained surgeons that allow us to perform such kind of specialized surgery.

Adult↗
PubMedDate not supplied

[The mechanisms of the dissemination and the treatment of ovarian metastases in colonic adenocarcinoma].

OBJECTIVE: The aims of this study are: 1) To known the frequency of ovarian metastasis, 2) to define the role of the surgical therapy and 3) to establish the mechanism of spread of colorectal cancer to the ovaries. MATERIAL AND METHODS: Between 1989 and 1993 624 patients with colorectal adenocarcinoma; were treated, 19 (7.7%) had ovarian metastasis; they were divided in 2 groups according to the diagnostic time: A) synchronous; B) metachronous. In most patients a peritoneal lavage were performed; the primary tumor was resected. RESULTS: The median age was 41.4 years. In group A: there were 9 patients; in 3 of them underwent elective surgery and in 6 an exploratory celiotomy due to colonic obstruction or perforation. The primary tumor was located in the sigmoid in 8 patients and in cecum in 1; the stage of the primary tumor was follows: B1, 2; B2, 3; C2, 4. The ovarian metastasis were located in the left ovary in 6; right, 2, and bilateral 1. The peritoneal lavage was positive in 6, and negative in 3. In group B: there were 10 patients; one underwent elective surgery and 9 exploratory celiotomy. The primary tumor was located in the sigmoid in 9, caecum in 1. The stage of the primary tumors were: B2, 4; C2 4; D, 2. The ovarian metastasis were located: left, 5; right, 1; bilateral, 4. The peritoneal lavage was positive in 6, negative in 2. The 5-year survival in group A was 16% in group B, 0%. CONCLUSION: Ovarian metastasis were associated with advanced metastatic diseases. The treatment of synchronous ovarian metastasis is the resection of primary tumor plus bilateral oophorectomy, and in metachronous metastasis it is palliative. The mechanism of spread to the ovaries is by direct implantation and hematogenous.

Adenocarcinoma↗
PubMedDate not supplied

[Induction of polyvalent immunity against Actinobacillus pleuropneumoniae in an experimental rat model].

Using an experimental model of passive immunity in the rat, the immunizing effect of live cells of Actinobacillus pleuropneumoniae serotypes 1, 3, 5, 7, 9 and 12 was tested against a challenge with serotype 1. It was observed that serotypes 5, 7 and 9 induced polyvalent immunity. Additionally, agglutinating antibodies to the homologous and heterologous serotype were titrated in the sera of immunized mothers; the results indicated that groups immunized with serotypes 5, 7 and 9 had higher titers against serotype 1.

Actinobacillus Infections↗