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Biomedical subjects

F J Castillo

Publications and source records attributed to F J Castillo.

51 records · Page 3Linked to original sources
PubMed1981

Growth inhibition activity and bacteriophage and bacteriocinlike particles associated with different species of Clostridium.

Thirty-four strains corresponding to 16 species of Clostridium were examined for growth inhibition activity and production of phage and bacteriocinlike particles. Twenty-five strains were found to inhibit growth of one or more of the other strains. The widest range of activity corresponded to C. bifermentans 18137 which inhibited growth of 23 strains. Cell-free filtrates of positive cultures were inactive with the exception of the one from C. bifermentans 18137. A wide variety of particles with diverse morphology was observed in lysates of cultures treated with mitomycin C (1 microgram/mL).

Bacteriocins↗
PubMed1980

Partial characterization of Pseudomonas phage 2 receptor.

The lipopolysacharide from Pseudomonas aeruginosa strain BI contains the receptors for phage 2 and strongly inactivates this phage in vitro (95-98% within 15 min). Several mono- and di-saccharides tested reduced phage 2 inactivation to 50% when present at the following concentrations: D-glucosamine, 0.25 M; maltose, 0.3M; lactose and cellobiose, 0.5 M; D-glucose, L-rhamnose, D-mannose, 2-deoxy-D-glucose, and sucrose, 1.0 M; D-galactose, D-xylose, and N-acetyl-D-glucosamine, 1.4 M; and melibiose. greater than 1.6 M. These results suggest the possibility that phage 2 receptors in lipopolysaccharide contain L-rhamnose, D-glucosamine, and (or) D-glucose, or a structurally related molecule. Either one of the latter two could be located at a terminal position alpha-linked to the adjacent residue, or located internally in the polysaccharide chain linked through its C-4 position.

Chemical Phenomena↗
PubMed1979

Production of Lactase by Candida pseudotropicalis Grown in Whey.

Lactase (beta-d-galactosidase) was produced by Candida pseudotropicalis grown in deproteinized whey. Maximum enzyme production in 2% whey was obtained by supplementation with 0.15% yeast extract, 0.1% (NH(4))(2)SO(4), and 0.05% KH(2)PO(4) (wt/vol). Highest enzyme values (4.35 U/mg of cells and 68 U/ml) were obtained with 10 to 12% whey, while enzyme yield was maximal in 2% whey (0.87 U/mg of whey). Optimal initial pH for cultivation was 3.5. The best conditions for extraction included 2% (wt/vol) chloroform, 10 h of treatment, pH 6.6 and higher, and 30 to 37 degrees C. Optimum pH and temperature for enzyme activity were 6.2 and 47 degrees C. The enzyme had a K(m) for O-nitrophenyl-beta-d-galactopyranoside of 3.06 x 10 M and the initial V(max) was estimated as 6.63 x 10 M per min. It hydrolized 50 and 100% of the lactose in whey and milk within 4 and 5 h, respectively, at 37 degrees C. The lyophilized enzyme retained 95% of activity for 3 months when stored at -20 degrees C.

Journal Article↗
PubMed1976

Localization and functional role of the pseudomonas bacteriophage 2 depolymerase.

The adsorption apparatus of phage 2 consits of a symmetrical base plate of snowflake appearance, composed of six droplike spikes 7.0 to 7.5 nm in length with a maximum diameter of 4.5 to 5.0 nm. The spikes are attached by their narrow ends to a central ring 7.0 to 7.5 nm in diameter. Phage 2 deopolymerase, a phage 2-induced hydrolytic enzyme, was found to be a structural protein of phage 2 or in close association with the base plate. Pdp1, a phage 2 mutant, possesses a polypeptide that is antigenically similar to the depolymerase, but devoid of hydrolytic activity. This polypeptide was found to be located in the region of the base plate of pdp1. Treatment of intact cells of strain BI with purified phage 2 depolymerase inhibited the adsorption of phage 2. When phage receptor-containing fractions of slime glycolipoprotein and lipopolysaccharide were hydrolyzed by the depolymerase, amino sugars were released, and the phage-inactivating activities of these fractions were lost. The depolymerase was also observed to induce the lysis of strain BI cells in hypotenic medium. The phage 2 depolymerase appears to play a role in adsorption and release of phage.

Adsorption↗
PubMed1974

Studies on the bacteriophage 2 receptors of Pseudomonas aeruginosa.

The lysogenization of Pseudomonas aeruginosa strain BI with phage 2 resulted in the loss of the capacity to adsorb the same phage. The absence of phage 2 receptors on the surface of the lysogenized strain BI(2)(8) was confirmed by the failure of purified slime polysaccharide (SPB) or lipopolysaccharide (LPS) to inactivate phage 2. SPB and LPS from a phage 2-resistant strain also failed to inactivate phage 2 in contrast to the phage inactivation exhibited by the SPB and LPS obtained from the wild-type strain BI. Chemically, quantitative differences were apparent when the SPB and LPS of strains BI(2)(8) and BI/2S(2) were compared with those of the wild-type strain BI. The most striking difference noted was the absence of amino sugars in the SPB of strain BI/2S(2). The SPB of strain BI(2)(8) also contained a lower percentage of amino sugars compared with the SPB of the wild-type strain BI.

Adsorption↗
PubMedDate not supplied

Respiratory cryptosporidiosis: case series and review of the literature.

Five case of intestinal cryptosporidiosis with pulmonary involvement in patients with AIDS are reported. The diagnosis was based on the recognition of acid-fast oocysts in sputum or aspirated bronchial material and stool specimens. Coughing and excess secretions were present in all cases. Four patients had other associated pulmonary pathogens: two Mycobacterium tuberculosis, one Mycobacterium fortuitum and one Cytomegalovirus + Pneumocystis carinii; all of them had a previous (three cases) or simultaneous (one case) diagnosis of intestinal cryptosporidiosis, presenting with diarrhoea and vomiting. In the fifth patient Cryptosporidium was the only pulmonary pathogen found in a bronchial aspirate, and the onset of diarrhoea was 1 month after respiratory detection. Fifty-seven cases of respiratory cryptosporidiosis have been reported since 1980. In 17 of them, no other pathogen was found. Diarrhoea was present in 77% of the patients, cough in 77%, dyspnea in 58%, expectoration in 54%, fever in 45%, thoracic pain in 33%.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Monitoring adenovirus infections with on-line and off-line methods.

Several known process monitoring methods were tested for their efficacy in the detection of adenovirus infections. The methods that we explored include several indirect indications of viral infections, including metabolic rate analysis, secondary gauges of respiration, cell size measurement, cell number and cell viability determination, and changes in capacitance. Direct indications of the adenovirus infection were also applied, including total viral particle and infectious particle measurements, as well as a flow cytometry method for detecting infected cells. All of the methods tested in the study provide some positive indication of an adenovirus infection. Many of the methods require repeated sampling, which may limit their utility in a manufacturing process. All of the indirect measures of viral infection may be limited by the fact that they do not uniquely identify an infection. The simplest monitoring methods appear to be detection of changes in respiration or the capacitance of the culture, both of which seem to provide a clear indication of an infection. Further work will be required to demonstrate that these indications are characteristic of only a successful and productive adenovirus infection.

Adenoviridae↗
PubMedDate not supplied

[Leukocyte migration inhibitory factor and basophil degranulation in drug reactions].

We performed a prospective study in patients with a medical history of adverse reaction to drugs with the purpose of rule out allergy. We included 31 patients who were attended in the Allergy Service. We compared the sensibility and specificity of the test of inhibition factor of leucocytes migration and degranulation basophil against the exposition. After the statistical analysis, we concluded: the laboratory test, we have already mentioned, have little sensibility and specificity so the exposition test in the quickest, useful, and more simple method to determine drugs allergy, but more dangerous.

Adolescent↗
PubMedDate not supplied

[Irradiation of the thyroid gland: changes in its function].

The authors have studied some usual parameters of the evaluation of the thyroid gland function, after secondary irradiation during tele-cobaltherapy treatment in 20 patients with larynx carcinoma. The parameters studied have been iodine uptake, Hamolsky index, T4, FT4 PB127I and cholesterol. The values, statistically treated, enable the conclusion that normal adult thyroid gland has a very low clinical and analytical radiosensibility.

Cholesterol↗