Biomedical subjects
Publications and source records attributed to C Roy.
Report of two cases of synovial cyst of the hip associated with moderate osteoarthritis. Diagnosis was made by computed tomography. Anatomic and radiologic characteristic findings of these synovial cyst are reviewed.
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A number of genes are transcriptionally regulated by interferons via a cis acting regulatory element (interferon consensus sequence). After incubation with HeLa cell nuclear extracts, a synthetic 29 mers probe representing the consensus was retarded as a single band whose amount increased after the addition of IFN to the cells. DNase I footprinting showed that a region of the non coding strand was protected differentially upon interferon treatment. After nuclear protein blotting and probing with the oligonucleotide, two proteins (114 and 50 kDa) of the desired specificity were revealed. Their absolute and relative amounts do not appear to be dependent of the IFN treatment.
We studied the efficacy of tazobactam (YTR 830), a new beta-lactamase inhibitor in combination with piperacillin (P) against 198 Enterobacteriaceae strains. A comparative study of susceptibility (MIC determined on Mueller Hinton agar; inoculum 10(4) cfu) was made with the combination amoxicillin (A) + clavulanic acid (CA). Of 181 strains resistant to P, 79.56% were susceptible to it in the presence of tazobactam (TZ). The characteristics of the beta-lactamases of 37 strains resistant to P + TZ (MIC greater than 40 micrograms/ml) were studied; 11 were hyperproducers of chromosomic beta-lactamase and 7 produced two types of plasmidic beta-lactamase. The MICs of TZ alone were uniform and high (64-128 micrograms/ml), independently of the characteristics of the strains beta-lactamase. Of 17 strains susceptible to P, the efficacy of P + TZ was significant among carriers of plasmidic beta-lactamase; there was practically no change in the P susceptibility among the non carriers. The efficacy of P + TZ was similar to that of A + AC against E. coli strains; it was higher against strains of Enterobacter, Citrobacter and Serratia.
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The bvg locus of Bordetella pertussis is required for coordinate regulation of several factors associated with virulence. The control system is modulated by various environmental signals, including low temperature, MgSO4, and nicotinic acid. The nucleotide sequence of the bvg region has been determined and three open reading frames, bvgA, bvgB, and bvgC, are present. Twelve-base-pair linker insertion mutations in any of these open reading frames result in a Bvg- phenotype. The predicted protein products of bvgA and bvgC share homology with a family of prokaryotic regulatory proteins that respond to environmental stimuli and are members of two-component sensory transduction systems. We propose a model in which BvgB and the N-terminal portion of BvgC are localized in the periplasm. Environmental signals are recognized, transduced to the cytoplasmic portion of BvgC, and then transmitted to BvgA, a positive regulator of transcription.
We studied the susceptibility to the amoxycillin/clavulanate combination (2:1), and the characteristics of the beta-lactamases, of 1410 amoxycillin-resistant strains of Enterobacteriaceae (785 of Escherichia coli and 625 of Klebsiella spp.). Of the E. coli strains, 97.07% were susceptible to the combination and 98.85% produced plasmid-mediated beta-lactamases. Of the Klebsiella spp. strains, 87.84% were susceptible to the combination and 75.36% produced plasmid-mediated beta-lactamases. In both cases, the differences in MIC values, according to the characteristics of the beta-lactamases of the strains, were statistically significant. Of the 99 strains of E. coli and Klebsiella spp. that were not inhibited by amoxycillin 16 mg/l with clavulanate 8 mg/l, 19 hyperproduced chromosomal beta-lactamase; five produced a plasmid-type beta-lactamase as well. Fifty-seven strains produced two plasmid-type beta-lactamases.
A plasmid (pBH10R3) containing a 9-kb Sst I fragment of HIV-1 (clone BH-10) inserted in pSP64, an in vitro expression vector, has been used for the transcription of anti-sense HIV-1 RNA. With this system, the transcripts obtained in vitro were not usually full length (1 to 2 kb long) and they predominantly span the 3' end ORF and ENV regions of the viral genome. We have rearranged the HIV-1 genomic sequences with respect to the SP6 promoter in the pSP64 vector and have obtained a series of new constructs allowing the expression in vitro of RNA transcripts complementary to other regions in the HIV-1 genome, including the 5' end of the ENV region as well as the TAT, POL, and GAG regions. In fact, the combined use of these constructs as templates for in vitro transcription allows the production of RNA probes spanning the entire viral genome. Compared with the 1- to 2-kb probes mentioned above, the combined use of such probes results in a several-fold increase in the sensitivity of molecular hybridization for the detection of HIV-1 nucleic acid sequences. Also, these constructs enable the preparation of RNA probes that have the potential to detect restriction polymorphisms throughout the HIV-1 genome.
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From 120 Pseudomonas aeruginosa strains selected for their slight susceptibility to ceftazidime (MIC greater than or equal to 16 micrograms/ml) we studied the characteristics of beta-lactamases and their susceptibility to aminoglycoside and to beta-lactam antibiotics. The quantitative spectrum, chromosomic beta-lactamase hyperproduction and the isoelectric point of beta-lactamases were also studied as well as the MIC in solid medium, inoculum 5 x 10(4) cfu. About 14.7% of strains moderately susceptible to ceftazidime and 88.4% of those resistant, were hyperproducers of chromosomic beta-lactamases. All the strains were resistant to ureidopenicillins, cefotaxime and moxalactam, 55.8% to monobactams and 35% were also resistant to cefsulodine; all of them were susceptible to imipenem. In bacteria isolated from twelve patients a loss of susceptibility could be observed against ceftazidime and other beta-lactams. There was also an increase in chromosomic beta-lactamase production during the treatment with antibiotics.
We studied the beta-lactamase activity characteristics of a penicillin G resistant N. meningitidis strain (MIC = 8 micrograms/ml) isolated from a septicemic process, in an eleven month old girl, attended in the Sabadell Hospital (Barcelona). The beta-lactamase substrate profile was broad-spectrum (it hydrolyses penicillin G and cephaloridine) and the nitrocefin hydrolysis was inhibited by clavulanic acid. The analytical isoelectric focusing of the enzyme showed that the isoelectric point of the main band and, the secondary bands, were compatible with those of the type TEM-1 standard enzyme. We also obtained a positive DNA-DNA hybridization with the TEM-1 beta-lactamase (pBR322 plasmid).
The authors report a surgical procedure for prevention of radiation enteritis performed in 24 cases of advanced gynecological and rectosigmoid malignancies with a 12-month median follow-up. Visualization and resorption of the Vicryl mesh were analyzed by means of magnetic resonance imaging.
Used in 13 cases of advanced gynecological and gastrointestinal carcinoma, pelvic exclusion using a suspension of the small intestine above the pelvis using absorbable material. The low-level of morbidity, value in dosimetric estimation, perfect feasibility and low cost of this technique should lead to its more widespread use whilst strictly respecting its indications. Nuclear magnetic resonance has been found to be a particularity novel and valuable method of post-operative investigation in visualisation and assessment of resorption of the polyglactine 910 trellis. Results in this series are analyzed at the end of a 5 to 14 month follow-up period and compared with data from experimental and clinical studies in the recent world literature.
The authors report a case where the diagnosis of complete pericardial agenesis was made by magnetic resonance imaging (MRI). This anomaly is rare, often asymptomatic (two-thirds of the cases) and its diagnosis may be evoked on a chest X-Ray and sonocardiography. MRI confirms the initial clinical impression and, besides, enables to completely rule out associated cardiac or pulmonary pathologies.
Report of a case of laryngitis beginning within the first 10 hours of life. The epiglottis was red, swollen, and covered by a membrane. Culture of laryngeal swabs isolated Streptococcus pneumoniae. Complete recovery was obtained with antibiotic therapy.
We have screened a genomic library of Trametes versicolor for genes whose expression is associated with nitrogen starvation, which has been shown to induce ligninolytic activity. Using two different approaches based on differential expression, we isolated 29 clones. These were shown by restriction mapping and cross-hybridization to code for 11 distinct differentially expressed genes. Northern analysis of the kinetics of expression of these genes revealed that at least four of them have kinetics of induction that parallel kinetics of induction of ligninolytic activity.
The exposure of mouse splenic lymphocytes to the microtubule assembly-promoting drug taxol (10 microM for 4 h) results in an extensive reorganization of the microtubule system to form one to a few large bundles of microtubules, which extend from the centrosome. Lymphocytes pretreated with taxol for 4 h, or cultured in the continued presence of taxol, respond normally to the mitogen concanavalin A up to, and including, the stage of DNA replication. In contrast, the induction of DNA synthesis during the alloactivation of lymphocytes is inhibited when taxol is present in the mixed leukocyte culture. If the stimulators are pretreated with this drug, the mixed leukocyte reaction occurs normally, but pretreatment of the responders inhibits the proliferative response markedly. Microscopic observations of nuclear morphologies in these populations and autoradiography indicate that taxol inhibition occurs early in alloactivation, prior to DNA replication. The responding ability of taxol-treated lymphocytes is not restored to control levels by the addition of interleukin 2, leading to the suggestion that interleukin 2 receptors do not emerge or function normally in these cells. We conclude that the capacity to respond to allogeneic cells, but not to a mitogen, is dependent on the presence of the normal submembranous organization of the microtubule system.
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