PubMed Health⌕ Search

Biomedical subjects

F Cabello

Publications and source records attributed to F Cabello.

At least 37 records · Page 2Linked to original sources
PubMed1989

The febrile father with a cytomegalovirus infection. A family affair.

Existing evidence has convincingly established that young children often transmit cytomegalovirus (CMV) infection to their parents. What proportion of these parental infections lead to clinical disease is unknown, but this sequence of events is probably not rare. Physicians seeing young adults with prolonged but otherwise nondescript febrile illness should inquire about the presence of young children in the household. Parental CMV infection is not limited to parents whose children attend day-care centers or are cared for in neonatal intensive care units. As in our case of the febrile father, it may be strictly a family affair.

Adult↗
PubMed1988

Further characterization of Escherichia coli O153:H45, an ETEC serotype disseminated in Chile.

The newly described stable enterotoxin producing, enterotoxigenic Escherichia coli, serotype O153:H45, capable of expressing colonizing factor antigen I, is frequently isolated as a cause of diarrhea among Chilean children. Hybridization studies of five new strains confirmed previous results which indicated that the stable enterotoxin genes are contained in nonconjugative plasmids ranging in size from 81 to 87 kilobases. The strains expressed similar antibiotic resistance and metabolic properties but differed in their plasmid content.

Antigens, Bacterial↗
PubMed1986

Bactericidal effects of the neodymium:YAG laser: in vitro study.

The effects of laser energy on three bacterial strains, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were studied utilizing the neodymium:YAG laser. Cell suspensions of each strain were divided into four groups. In group I, suspensions from each strain were exposed to laser energy densities of 555-3,333 J/cm2. In groups II and III, two artificial dyes, congo red or methylene blue, were added to the suspensions prior to lasing. In group IVa, no laser energy was used, and group IVb was used to measure the bactericidal thermal effects of the laser. It was concluded that: Low dosages of laser energy exceeding 1,667 J/cm2 resulted in a 2 to 8 log decline in the number of viable bacterial colonies in vitro. Compared to the other two bacterial strains, P aeruginosa was the most sensitive to YAG laser irradiation. Addition of methylene blue, a dark-colored dye, enhanced the bactericidal effects of the YAG laser as indicated by the significantly reduced viability of P aeruginosa after irradiation with 2,222 J/cm2.

Catechols↗
PubMed1986

Persistence of multiply antibiotic-resistant Campylobacter jejuni in a patient with the acquired immune deficiency syndrome.

Chronic diarrhea due to Campylobacter jejuni has been described in patients with hypogammaglobulinemia. A patient with the acquired immune deficiency syndrome (AIDS) and normal total serum immunoglobulins had persistent diarrhea and C. jejuni on stool culture for seven and a half months despite repeated antibiotic therapy. Antibiotic sensitivity studies revealed the C. jejuni to be multiply antibiotic-resistant. Evaluation of the mechanism of resistance showed the organism harbored a conjugative plasmid capable of transferring resistance to tetracycline, but not to other antibiotics. It is concluded that C. jejuni infection may rarely result in chronic diarrhea in patients with AIDS. The combination of an immune deficiency state including abnormal B cell function previously described in AIDS and multiple antibiotic resistance may have contributed to the persistence of the organism in this case.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Fetal scalp temperature during labor and its relation to acid-base balance and condition of the newborn.

Fetal scalp temperature and fetal-maternal temperature gradient were studied during well-established labor in a group of 97 patients using a technique that ensured at the same time the adhesion and the thermal insulation of the probe. In 78 infants with a one-minute Apgar score of 7 or above, a positive gradient of 0.2C was maintained throughout labor between the warmer fetal scalp temperature (37.3C) and the maternal rectal temperature. Periodic drops of temperature related to the uterine contractions occurred in only 43% of the cases. In a group of ten infants with a one-minute Apgar score of 6 or below, the fetal-maternal gradient was significantly different from this schema. There was an inversion of the gradient, the fetal scalp temperature becoming cooler (36.9C) than the maternal rectal temperature. The gradient was -0.2C at the beginning of the study and -0.5C 20 minutes before delivery. Periodic drops of temperature with uterine contractions were constant. In dead fetuses, fetal scalp temperature was much below that of the mother and this difference increased steadily until delivery. A good relationship was found between fetal-maternal gradient and the pH of the umbilical artery blood sampled at birth. When the mean gradient was 0.2C +/- 1 SD, pH averaged 7.27; in the group below 1 SD, mean pH was 7.19 (P less than .01).

Acid-Base Equilibrium↗
PubMed1979

Plasmid replication functions. II. Cloning analysis of the repA replication region of antibiotic resistance plasmid R6-5.

R6-5 is a low copy number, conjugative, FII incompatibility group plasmid that has a molecular length of 102 kb and that specifies resistance against several antibiotics (chloramphenicol, fusidic acid, kanamycin, streptomycin and sulphonamide) and mercury salts. By means of in vitro cloning procedures, mini plasmids have been generated that contain a DNA segment from the essential region of R6-5 that is only 2.6 kb in length. This DNA segment, which consists of two PstI fragments that are adjacent in the parent plasmid, carries all genes and sequences required for the regulated replication and incompatibility properties of R6-5, including its origin of replication, OriV, an essential function that has been designated RepA, and the copy control function, Cop. Three different polypeptides, having monomer molecular weights of 23,000, 10,000 and 9,500 daltons, are synthesized in detectable quantities by minicells carrying pBR322 hybrid plasmids that contain DNA segments from the R6-5 essential region. A spontaneous deletion derivative of a pBR322 hybrid plasmid that carries the R6-5 origin of replication was isolated. Heteroduplex analysis of this derivative plasmid indicates that the deleted DNA segment carries the R6-5 replication origin and that its termini consist of short inverted repeat sequences.

DNA Polymerase I↗
PubMed1978

Instability of plasmid DNA sequences: macro and micro evolution of the antibiotic resistance plasmid R6-5.

Detailed examination of the structure of cloned DNA fragments of the R6-5 antibiotic resistance plasmid has revealed a substantial degree of polynucleotide sequence heterogeneity and indicates that sequence rearrangements in plasmids and possible other replicons occur more frequently than has hitherto been appreciated. The sequences changes in cloned R6-5 fragments were shown in some instances to have occurred prior to cloning, i.e. existing in the original population of R6-5 molecules that was obtained from a single bacterial clone and by several different criteria judged to be homogeneous, and in others to have occurred either during the cloning procedure or during subsequent propagation of hybrid molecules. The molecular changes that are described involved insertion/deletion of the previously characterized IS2 insertion element, formation of a new inverted repeat structure probably by duplication of a preexisting R6-5 DNA sequence, sequence inversion, and loss and gain of restriction endonuclease cleavage sites.

Anti-Bacterial Agents↗
PubMed1978

Cloning and characterization of EcoRI and HindIII restriction endonuclease-generated fragments of antibiotic resistance plasmids R6-5 and R6.

DNA fragments generated by the EcoRI of HindIII endonucleases from the low copy number antibiotic resistance plasmids R6 and R6-5 were separately cloned using the high copy number ColE1 or pML21 plasmid vectors and the insertional inactivation procedure. The hybrid plasmids that were obtained were used to determine the location of the EcoRI and HindIII cleavage sites on the parent plasmid genomes by means of electron microscope heteroduplex analysis and agarose gel electrophoresis. Ultracentrifugation of the cloned fragments in caesium chloride gradients localized the high buoyant density regions of R6-5 to fragments that carry the genes for resistance to streptomycin-spectinomycin, sulfonamide, and mercury and a low buoyant density region to fragments that carry the tetracycline resistance determinant. Functional analysis of hybrid plasmids localized a number of plasmid properties such as resistances to antibiotics and mercury and several replication functions to specific regions of the R6-5 genome. Precise localisation of the genes for resistance to chloramphenicol, kanamycin, fusidic acid and tetracycline was possible due to the presence of identified restriction endonuclease cleavage sites within these determinants. Only one region competent for autonomous replication was identified on the R6-5 plasmid genome and this was localized to EcoRI fragment 2 and HindIII fragment 1. However, two additional regions of replication activity designated RepB and RepC, themselves incapable of autonomous replication but capable supporting replication of a linked ColE1 plasmid in polA- bacteria, were also identified.

Bacteriocin Plasmids↗
PubMed1976

Replication control in a composite plasmid constructed by in vitro linkage of two distinct replicons.

Although it carries two competent replication systems, a composite plasmid formed in vitro by linkage of the complete ColE1 and pSC101 plasmid replicons at their unique EcoRI endonuclease cleavage sites normally uses only the replication origin and functions of the ColE1 component. Restriction of ColE1 replication functions by DNA polymerase I deprivation results, however, in exclusive use of the pSC101 replication origin. When using the ColE1 replication system the composite plasmid is nevertheless incompatible with both the parent replicons. This suggests that a trans-dominant gene product is involved in plasmid incompatibility and supports negative control rather than positive control models for regulation of the initiation of DNA replication.

DNA Replication↗