PubMed Health⌕ Search

Biomedical subjects

R García

Publications and source records attributed to R García.

At least 235 records · Page 13Linked to original sources
PubMed1977

Immunohistologic findings in the lung in systemic lupus erythematosus.

A 29-year-old woman with systemic lupus erythematosus (SLE) developed dyspnea, hemoptysis, pleuropericarditis, and azotemia shortly after an episode of arthritis and progressive hair loss. She had a high titer of radioimmune anti-DNA Antibodies, positive fluorescent anti-smooth muscle antibodies, and depressed C3 levels in her serum. Antiglomerular basement membrane antibodies were negative, and the titer of antibodies against extractable nuclear antigen was within normal limits. Cryoglobulins and lupus erythematosus cell preparations were negative. Despite steroid therapy and other supportive measures, including dialysis, she died ten days after admission. Percutaneous renal and pulmonary biopsies were performed postmortem at bedside and were processed for immunohistology. Identical granular deposits of C3 and IgG were found in both the lungs and the kidneys. This finding suggests that a common pathogenetic mechanism is operating in the development of pneumonitis and nephritis in SLE, and is in agreement with the currently held views on immune-complex diseases.

Adult↗
PubMed1976

Kallikreinlike activity in perfusates and urine of isolated rat kidneys.

In the perfusate and the urine produced during perfusion of isolated rat kidneys a kallikreinlike enzyme similar to that found in the kidney was detectable by bioassay 15-25 min after the beginning of the perfusion. The source of the kallikrein activity was the kidney itself, since before the perfusion was started the blood remaining in the kidneys was washed out and the perfusion medium was free of kallikrein and its precursors and substrates. The kallikreinlike activity of the perfusate was characterized by a) an oxytocic effect on isolated rat uterus, b) a kininogenase activity on kininogen II, c) an esterase activity on N-benozyl-L-arginine ethyl ester, and d) a hypotensive effect on anethetized rats. These properties were inhibited by diisopropyl activity in the perfused kidney was lower than that in the nonperfused organ, but the total amount of kallikrein activity released to the excreted urine and the perfusate was significantly greater than the corresponding activity that disappeared in the kidney. This result is in keeping with the concept that the renal tissue is able to synthesize kallikrein.

Animals↗
PubMedDate not supplied

An optimized amphiphilic cationic peptide as an efficient non-viral gene delivery vector.

BACKGROUND: Due to their chemical definition and reduced size, the use of peptides as gene delivery systems is gaining interest as compared to the more common polymeric non-viral vectors. To achieve gene transfer efficiencies that would make peptides a realistic alternative to existing methods, we have evaluated and attempted to concert those properties with a direct impact on the activity of the system. These considerations have led to the design, synthesis and characterization of a 23-residue cationic peptide which we term RAWA. METHODS: We have characterized RAWA biophysically and functionally. Biophysical studies include evaluation of DNA condensation and membrane perturbing activities. DNA transfer activity has been evaluated in cell culture at controlled DNA-to-peptide stoichiometries, using a luciferase gene as reporter. Requirements for additional effectors such as chloroquine and peptide cofactors have also been considered. RESULTS: RAWA displays in vitro DNA condensing activity similar to that of protamines, reaching maximum effect at a peptide-to-DNA molar charge ratio (CR) of 4 (+/-). The reduced membrane perturbing activity diminishes its cytotoxic potential. In COS-7 cells, transfection efficiency with RAWA peptiplexes, compares favorably with well-recognized systems, including Lipofectamine Plus, Superfect, GenePorter and FuGene. The peptide-associated activity between free and DNA-bound species has been mapped by analyzing dependency on chloroquine treatment. The lack of significant serum inhibition and low toxicity make this system advantageous for potential in vivo application. A ternary complex including the acid-triggered fusogenic JTS-1 peptide is presented as a potential strategy for further in vivo studies. CONCLUSIONS: We have developed a gene delivery system based on an amphipathic cationic peptide with improved DNA condensation ability and reduced cytotoxicity, which maintains membrane binding and perturbing activities. Observed efficiency with this molecule is very high and compares favorably with currently available transfection systems.

3T3 Cells↗
PubMedDate not supplied

[Bone mineral density in children with osteogenesis imperfecta].

OBJECT: Osteogenesis imperfecta is the term used for a group of disorders of collagen synthesis which cause increased bone fragility. The aim of our study was to evaluate the BMD in patients with OI. MATERIAL AND METHODS: We used dual-energy x ray absorptiometry, Hologic QDR 4500W (DEXA), to compare the bone mineral density (BMD) of 8 patients aged from 3 years to 20 years who had osteogenesis imperfecta with an age and sex matched control group. RESULTS: DEXA detected highly significant differences in BMD respecting control group. The mean BMD in the patients with osteogenesis imperfecta was 62.6 % of normal in lumbar spine (p < 0.01) and 63.01 % of normal in the femoral neck (p < 0.01) using Wilcoxon test. CONCLUSION: DEXA is an objective, reproductible and sensitive method of measurement of BMD in children. It may help to stablish the diagnosis, to asses prognosis and possibly to monitor the response to different types of treatment.

Absorptiometry, Photon↗
PubMedDate not supplied

[Problems and proposals for improvement in the health care of economic immigrants].

OBJECTIVES: To analyse existing problems in health care to economic immigrants from the point of view of health and social professionals, health authorities and economic immigrants and to know which will be their proposals and priorities to improve economic immigrants's health assistance. METHODS: Qualitative approach study made in Majorca island. (Spain). Three focus groups and three nominal groups with health and social workers from primary health care and hospital services were carried out as well as two partially structured interviews to health authorities, one Autonomic Authority and one Governmental Authority, and twelve partially structured interviews to economic immigrants identified trough key informants. RESULTS: Health and social workers perceive the increase in the number of economic immigrants as a massive arrival. The main problems identified are: access restrictions to public health services for economic immigrants, the follow-up of these patients and diagnostic difficulties because lack of training in tropical medicine. Health and social workers's first proposal for improving this situation is their own training in tropical medicine. Autonomic Authority priorities are to guarantee access to public health services for all immigrants and to look actively for health problems in these population. Governmental Authority, instead, holds the legalization for all. In fact, economic immigrants are not concerned on health care because legalization and housing problems. CONCLUSIONS: The main barriers identified by health and social workers in health care to economic immigrants are: access restrictions, follow-up and lack of training in tropical medicine. Health and social first proposal to improve this situation is their own training in tropical medicine while Autonomic and Central Authorities's priorities are not the same. For economic immigrants, health assistance is not their biggest concern.

Delivery of Health Care↗
PubMedDate not supplied

Imaging cobalt nanoparticles by amplitude modulation atomic force microscopy: comparison between low and high amplitude solutions.

In many situations of interest amplitude modulation AFM is characterized by the coexistence of two solutions with different physical properties. Here, we compare the performance of those solutions in the imaging of cobalt nanoparticles. We show that imaging with the high amplitude solution implies an irreversible deformation of the nanoparticles while repeated imaging with the low solution does not produce noticeable changes in the nanoparticles. Theoretical simulations show that the maximum tip-surface force in the high amplitude solution is about 14nN while in the low amplitude solution is about -4nN. We attribute the differences in the high and low amplitude images to the differences in the exerted forces on the sample.

Journal Article↗
PubMedDate not supplied

[Quality improvement of the filling medication trolleys process, for an unit-dose drug distribution system].

OBJECTIVE: To assess the quality of filling medication trolleys process for an unit-dose drug distribution system, after the implantation of a protocol. METHOD: Five criteria were defined: four were related to the medication given to the patient, and one criterion was related to the patient's identification. At the same time, it was designed a standardized protocol of filling medication trolleys process and it was evaluated the degree of compliance with the criteria on all the hospitalized patients medication drawers in two clinical units. The fulfilment of the criteria was measured both before and after the implantation of the protocol, for fourteen and seven days respectively. RESULTS: In the first evaluation the number of errors was 0.84/medication drawer. After the implantation of the protocol, the total number of errors after correction for sample size decreased at 0.22/medication drawer. The degree of compliance improved for all the criteria, and differences were statistically significant for the criteria with most errors. CONCLUSIONS: The implantation of a protocol significantly improved two of the five quality criteria studied in the filling medication trolleys process. The patient's identification has been revealed as a fundamental aspect of intervention in the dispensation quality.

Clinical Protocols↗
PubMedDate not supplied

Nasal biopsies of children exposed to air pollutants.

Southwest Metropolitan Mexico City (SWMMC) atmosphere is a complex mixture of air pollutants, including ozone, particulate matter, and aldehydes. Children in SWMMC are exposed chronically and sequentially to numerous toxicants, and they exhibit significant nasal damage. The objective of this study was to assess p53 accumulation by immunohistochemistry in nasal biopsies of SWMMC children. We evaluated 111 biopsies from 107 children (83 exposed SWMMC children and 24 control children residents in a pollutant-compliant Caribbean island). Complete clinical histories and physical examinations, including an ear-nose-throat (ENT) exam were done. There was a significant statistical difference in the upper and lower respiratory symptomatology and ENT findings between control and exposed children (p < 0.001). Control children gave no respiratory symptomatology in the 3 months prior to the study; their biopsies exhibited normal ciliated respiratory epithelium and were p53-negative. SWMMC children complained of epistaxis, nasal obstruction. and crusting. Irregular areas of whitish-gray recessed mucosa over the inferior and middle turbinates were seen in 25% of SWMMC children, and their nasal biopsies displayed basal cell hyperplasia, decreased numbers of ciliated and goblet cells, neutrophilic epithelial infiltrates, squamous metaplasia. and mild dysplasia. Four of 21 SWMMC children with grossly abnormal mucosal changes exhibited strong transmural nuclear p53 staining in their nasal biopsies (p 0.005, odds ratio 26). In the context of lifetime exposures to toxic and potentially carcinogenic air pollutants, p53 nasal induction in children could potentially represent. a) a checkpoint response to toxic exposures, setting up a selective condition for p53 mutation, or b) a p53 mutation has already occurred as a result of such selection. Because the biological significance of p53 nuclear accumulation in the nasal biopsies of these children is not clear at this point, we strongly suggest that children with macroscopic nasal mucosal abnormalities should be closely monitored by the ENT physician. Parents should be advised to decrease the children's number of outdoor exposure hours and encourage a balanced diet with an important component of fresh fruits and vegetables.

Air Pollutants↗