PubMed Health⌕ Search

Biomedical subjects

C Ramírez

Publications and source records attributed to C Ramírez.

At least 73 records · Page 4Linked to original sources

Morphological changes in strains of Aspergillus flavus Link ex Fries and Aspergillus parasiticus Speare related with aflatoxin production.

Two strains of Aspergillus flavus Link ex Fr. and two strains of A. parasiticus Speare were cultured on crushed moist wheat (Triticum durum var. Pané no. 257) for aflatoxin production studies in correlation with morphological changes. The toxicogenic strains were adapted to the substratum by means of successive transfers at regular intervals (72 h.) The amount aflatoxins synthesized by the toxicogenic strains decreased gradually after succesive subculturing. The decrease was accompanied by marked morphological changes. One of the strains studied, A. flavus NRRL 3251, lost completely the capacity of aflatoxin synthesis after several subcultures, presenting at the same time strong morphological variations. A. flavus CBS 120.62 also lost its toxicogenicity after six subcultures.

Aflatoxins↗

Some new species of Penicillium recovered from the atmosphere in Madrid and from other substrata.

Six new species of Penicillium Link ex Fries are described and illustrated. Four of them have been recovered from the atmosphere in Madrid, Spain, the other two species were isolated from must and from soil respectively. They clearly differ from all species of the genus described so far and are, therefore described and proposed as new taxa: Penicillium gerundense sp. nov., Penicillium valentinum sp. nov., Penicillium alicantinum sp. nov., Penicillium malacaense sp. nov., Penicillium tarraconense sp. nov., and Penicillium vasconiae sp. nov.

Air Microbiology↗

Four new species of penicillium isolated from the air.

Four new species of Penicillium Link ex Fries are described and illustrated. All of them but one have been isolated from the atmosphere in Madrid. Spain. They clearly differ from all species of the genus described so far and are, therefore, described and proposed as new taxa: Penicillium aurantio-flammiferum sp. nov., Penicillium gallaicum sp. nov., Penicillium granatense sp. nov., and Penicillium ilerdanum sp. nov.

Air Microbiology↗

Air-borne fungi in Barcelona City (Spain). I. A two-year study (1976-1978).

Quantitative and qualitative studies were made of the fungi of the air in Barcelona City. The genera Cladosporium and Alternaria formed two of the most important components of the fungus population studied during a two-year period running from January 1976 through January 1978. Penicillium species formed the 16.3% of the total colonies while Aspergillus species represented only the 2.8%. The occurrence of the genera was greatly affected by climatic conditions. An attempt was made to summariza the data of various kinds of fungi on a volumetric basis. Most of the fungi reported here have been identified as far as genera.

Air Microbiology↗

Air-borne fungi in the air of Barcelona (Spain). II. The genus alternaria.

The genus Alternaria Nees formed one of the more important components of the fungus population of the air at Barcelone (Spain), during a two-year study, from February 1976 through January 1978. Results were based only on studied of colonies obtained by gravity-exposed plates. The occurrence of this genus was greatly affected by climatic conditions. In general. however, Alternaria appeared to prefer warmer weather. A total of six species of Alternaria was identified, of which, Alternaria alternata (Fries) Keissler was by far the commonest, representing 71.3% of all colonies.

Air Microbiology↗

Chromosomal variations in the primate Alouatta seniculus seniculus.

Chromosome analysis in 23 specimens of Alouatta s. seniculus trapped in different localities of Colombia were examined with the C- and Q-banding techniques. The chromosome numbers (2n=44) showed variations from 2n = 43 to 2n = 45 involving three and five microchromosomes, respectively. Two specimens also showed a structural chromosome variation involving a pericentric inversion of the chromosome No. 13. Chromosome measurements revealed an X chromosome with a value significantly smaller to that established for the standard mammalian X chromosome.

Alouatta↗