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V Rosas

Publications and source records attributed to V Rosas.

8 recordsLinked to original sources
PubMed2001

RepA negatively autoregulates the transcription of the repABC operon of the Rhizobium etli symbiotic plasmid basic replicon.

The basic replicon of Rhizobium etli CE3, like other members of the repABC plasmid family, is constituted by the repABC operon. RepC is essential for replication, and RepA and RepB play a role in plasmid segregation. It has been shown that deletion derivatives lacking the repAB genes have an increased copy number, indicating that these genes participate in the control of plasmid copy number. RepA is also a trans-incompatibility factor. To understand the regulation of the repABC operon, in this paper: (i) the transcription start site of the repABC operon was determined; (ii) the promoter region was identified by site-directed mutagenesis of the putative -35 and -10 hexameric elements; and (iii) RepA was recognized as a negative regulator of the transcription of the repABC operon.

Bacterial Proteins↗
PubMed2000

Lung transplantation and systemic sclerosis.

We performed lung transplantation in nine patients with Scleroderma related lung disease. Patient characteristics included: 7 (78%) females, 6 (67%) with limited and 3 (33%) with diffuse Scleroderma. Pulmonary fibrosis was present in 7 (78%) and pulmonary hypertension in 4 (44%). All patients were carefully screened by the Johns Hopkins and University of Maryland Scleroderma Center and only referred for transplantation when concomitant renal insufficiency (creatinine clearance < or = 50 ml/min), aspiration, and skin brakdown were excluded. When compared to a similar group of transplant patients with nonscleroderma lung disease (primary pulmonary fibrosis), there was no significant difference in post-transplant survival at four years (76.2 +/- 0.15% vs. 69.2% +/- 0.12%), mean annual incidence rate for acute rejection (0.14 +/- 0.14 vs. 0.47 +/- 0.13) and infection (viral 0.17 +/- 0.17 vs. 0.29 +/- 0.11) (bacterial 0.17 +/- 0.17 vs. 1.4 +/- 0.4) (fungal 0.99 +/- 0.69 vs. 0.36 +/- 0.16) or serum creatinine (1.55 +/- 0.34 mg/dl vs. 1.15 +/- 0.09 mg/dl). We conclude that lung transplantation is viable option for carefully selected patients with scleroderma related lung disease.

Contraindications↗
PubMed1997

Permeability of the blood-retinal barrier in healthy humans. European Concerted Action on Ocular Fluorometry.

BACKGROUND: The aim of this study was to compare the inward permeability of the blood-retinal barrier in healthy subjects from six European cities. METHODS: Seventy-two healthy subjects (age 20-70 years) were selected. At 30 min and 60 min after fluorescein injection, fluorescein mass in vitreous was calculated from the concentrations measured along the optical axis of the eye. Non-protein-bound fluorescein (NPBF) concentrations were measured in plasma prepared from blood samples taken 7, 15 and 55 min after injection. Blood-retinal barrier permeability (PBRB) was calculated from the vitreous fluorescein mass and the time integral of NPBF and was corrected for the autofluorescence of ocular tissue and for lenticular light transmittance. RESULTS: Mean PBRB values +/- SD (nm.s-1) were 2.07 +/- 0.54 (Coimbra), 2.01 +/- 0.43 (Frankfurt), 2.24 +/- 0.50 (Ghent), 2.37 +/- 0.56 (Herlev), 1.89 +/- 0.44 (Leiden) and 1.74 +/- 0.38 (Porto). Differences between centers were not significant (P > 0.35). Measurements were reproducible and independent of the time after fluorescein injection (P > 0.50). A PBRB higher than 3.16 nm.s-1 or a value which had increased by 32% was considered abnormal (P < 0.05). CONCLUSION: PBRB values were similar in all centers. The results demonstrate that this is a highly sensitive and reliable method for measuring the permeability of the blood-retinal barrier.

Adult↗
PubMed1992

Long-term follow-up of central serous retinopathy in 150 patients.

To study the evolution of the retinal pigment epithelial lesions in the central serous retinopathy, the authors studied 150 patients with ages between 20 and 49 years at the first examination, during periods varying between 6 months and 14 years. It was found a greater incidence of the disease in the males (83.3%); bilaterality in 23.3%; only one point of leakage in 62.7%; 3 different types of diffusion (inkblot 71.4%; mushroom 23.8%; with serous pigment epithelial detachment 4.9%). The final visual acuity was < 20/40 in a quarter of the cases and the frequency of the recurrences was 30%. The laser treatment did not influence the recurrences. In 50 patients with a follow-up superior to 3 years, 8 (16%) developed lesions similar to those described as diffuse retinal pigment epitheliopathy with visual field defects and subnormal EOG. Actuarial calculus suggests that 50% of the patients may get the most severe and extensive form of the disease after 12 years of evolution. The results allow to conclude that the diffuse retinal pigment epitheliopathy is only the terminal state of the most severe cases of central serous retinopathy.

Adult↗
PubMedDate not supplied

Retinal complications after bungee jumping.

Bungee jumping is becoming a popular sport in the Western world with some cases of ophthalmic complications being reported in recent literature. The authors reported a case of a 23-year-old healthy female who presented retinal complications following a bungee jumping. Her fundi showed superficial retinal hemorrhages in the right eye and a sub-internal limiting membrane hemorrhage affecting the left eye. A general examination, including a full neurological examination, was normal and laboratorial investigations were all within normal values. More studies are necessary to identify risk factors and the true incidence of related ocular lesions, but until then, we think this sport activity should be desencouraged, especially to those that are not psychological and physically fit.

Adult↗
PubMedDate not supplied

Evaluation of diabetic retinopathy by fluorophotometry. European concerted action on ocular fluorometry.

BACKGROUND: Fluorophotometric variables (permeability of the blood-retinal barrier (BRB) and blood-aqueous barrier (BAB), corneal autofluorescence, and lenticular light transmittance) are reported to correlate with the severity of diabetic retinopathy. This preliminary multicenter study was performed to measure these variables simultaneously in patients with type 2 diabetes mellitus and to assess which of these variables could be of help in evaluating diabetic retinopathy. METHODS: Eighty-two patients with type 2 diabetes and diabetic retinopathy were recruited in seven European university clinics. Each patient was investigated three times, at intervals of about one year. The investigations included fluorophotometric determination of corneal autofluorescence, lenticular light transmittance, and permeability of the BRB and BAB. Retinopathy was classified into four grades, using a simplified evaluation system based on the Modified Airlie House retinopathy classification and applied to color fundus slides of standard fields 1 and 2. RESULTS: Multiregression analyses revealed that only corneal autofluorescence and BRB permeability were correlated with the severity of diabetic retinopathy (P < 0.05). Corneal autofluorescence and BRB permeability as single variables were found to be indicative of severe nonproliferative retinopathy and proliferative retinopathy (sensitivity 100% and 86%, respectively, and specificity 65% and 85%, respectively). Combination of both variables increased specificity to 92%. CONCLUSIONS: This preliminary multicenter study shows that fluorophotometric variables can be measured simultaneously and reliably in patients with diabetes and that corneal autofluorescence and BRB permeability (individually or in combination) could be of help in detecting severe non-proliferative retinopathy and proliferative retinopathy.

Blood-Aqueous Barrier↗
PubMedDate not supplied

[Immediate reaction to latex: comparison between skin test and IgE determination with ELISA].

BACKGROUND: Development of latex hypersensitivity type 1 response mediated by IgE depends on exposition intensitivity and genetic predisposition. Clinical manifestations are urticaria, rhinoconjunctivitis, asthma and anaphylaxis. OBJECTIVE: The aim of the study was to determine the frequency of latex immediate skin reactivity on allergy patients from 1-15 yr old from Hospital Infantil de México. METHODS: A clinical, prospective trial was performed between november 1998 and april 1999. During the study we documented 629 patients with allergy. Of them 30 had positive skin prick test (SPT) to latex according to Aas classification and 30 with negative SPT were randomly chosen as control group. Both groups were similar with respect to diagnosis, age, and sex characteristics. RESULTS: 629 children's with SPT, 30 had positive skin princk test (4.76%), 15 men and 15 women, with an average age of 8.9 years. For groups 1-5 years of age. The group age 6-10 years 6.21% and that of age 11-15 8.9%. Atopia antecedent 73.3%. For rhinitis and asthma diagnostic 63%, rhinitis 13%, asthma 20%, conjunctivitis 20%, atopic dermatitis and anaphylaxis 3.3%, urticaria 6.6%. Surgery antecedent 30%. 100% used a sucking, 93% used a latex toy the relationship of symptoms with the use of latex was 6.6%. Statistica1 ana1ysis was performed using: Nonparametric correlations the Kendall's tau-b: 0.329 and Spearman's rho 0.348 correlation is significant. CONCLUSION: It does exist a correlation between SPT and test for latex-especific IgE antibodies, the older the patient, the higher frequency of latex reaction, history of atopy is the mayor risk factor.

Adolescent↗