Biomedical subjects

L Garcia

Publications and source records attributed to L Garcia.

At least 73 records · Page 4Linked to original sources

PubMed1996

The health insurance status of US Latino women: A profile from the 1982-1984 HHANES.

OBJECTIVES: This research studied the correlates of health insurance status among three major subpopulations (Mexican, Puerto Rican, and Cuban) of adult (ages of 20 to 64) Latino women. METHODS: Data from the Hispanic Health and Nutrition Examination Survey (HHANES), 1982-1984, were examined to determine the percentages of health insurance coverage among the sample populations and to assess the relationship between access to coverage and selected sociodemographic employment/income, ancestry, and acculturation variables. RESULTS: Variations in health insurance coverage existed by Latina subpopulation. While Puerto Rican women had the highest percentage of any health insurance coverage, Mexican-origin women (particularly those 50 to 64 years old) had the lowest. For all three Latina groups, health insurance coverage was greater among those who reported a family income above the poverty level than among those whose income fell below the poverty level; employment location, acculturation variables, and ancestry were also related to coverage. CONCLUSIONS: Eligibility requirements, particularly for Mexican-and Cuban-origin women, need to be streamlined, and innovative health insurance programs need to be developed to increase access of Latinas to health insurance.

Acculturation↗

PubMed1996

Myocardial revascularization with the radial artery: a clinical and angiographic study.

BACKGROUND: It has been well documented that the use of the internal thoracic artery yields better long-term patency rates than saphenous vein grafts for coronary artery bypass grafting. This knowledge has prompted surgeons to use other arterial conduits such as the radial artery. METHODS: Between April 1994 and January 1996, radial artery grafts were used in 83 patients (mean age, 54.6 years) undergoing myocardial revascularization. All patients received diltiazem, 80 mg orally three times daily. Angiographic studies were performed in the early post-operative period in 61 patients, and 6 to 19 months later in 12 patients. RESULTS: There were four hospital deaths (4.8%), none of them due to cardiac causes. Perioperative myocardial infarction was observed in 3 patients, 1 related to a radial artery graft occlusion. Of 61 grafts studied early, 59 were patent (96.7%), but two grafts showed diffuse spasm. Twelve patients had a second angiogram after a mean interval of 8.7 months, and all grafts were patent. One patient who had a diffuse spasm at the early study had recurrent symptoms, and repeat angiogram showed further narrowing of the graft (string sign). CONCLUSIONS: Our results suggest that with proper care, the radial artery may be used for coronary artery bypass grafting with good early results. Long-term follow-up and angiography studies will be needed to establish the merit of the radial artery as a graft for coronary artery operations.

Administration, Oral↗

PubMed1996

[Aortic valve replacement with pulmonary autograft (Ross procedure). Initial experience].

PURPOSE: Report the initial surgical experience with four cases utilizing a pulmonary autograft for aortic valve replacement. METHODS: Four patients, all males, white, age between 23 and 46 years having aortic valve disease were submitted to aortic valve replacement with a pulmonary autograft using the root replacement technique. Right ventricular outflow tracts were reconstructed with antibiotic sterilized pulmonary or aortic homografts. All patients had control bidimensional eco-doppler (ECO) and hemodynamic study to evaluate the function of the implanted auto and homografts. RESULTS: All patients had an excellent post-operative recovery, without the necessity of inotropic drugs. All presented in normal sinus rhythm. Post-operative ECO and hemodynamic studies revealed excellent function of the implanted autografts, without gradients in three and with a 15mmHg mean residual gradient in one case. There was no regurgitation in three cases and only trace aortic insufficiency in one. The right sided homografts also showed good function, with no gradient in two cases and mean systolic gradient of 6 and 8mmHg in the other two. CONCLUSION: The pulmonary autograft procedure should be implemented definitely in our country.

Adult↗

PubMed1996

Targeting widespread sites of damage in dystrophic muscle: engrafted macrophages as potential shuttles.

Inherited muscle diseases are characterized by widespread muscle damage in the body. This limits the clinical relevance of cell or gene therapy based upon direct injections into muscles. One way to circumvent this obstacle would be to use circulating cells, capable of homing naturally to the sites of lesion, to deliver therapeutic substances. Certain muscular dystrophies present successive cycles of degeneration-regeneration. These sporadic necrotic lesions trigger local inflammations with subsequent infiltration of blood-borne mononuclear cells. We have, therefore, tested the possibility that homing monocytes and macrophages could be appropriate shuttles for delivering a therapeutic agent to disseminated pathogenic sites, their targeting being triggered by the pathogeny itself. First, fluorescently labeled immortalized monocytes were intravenously injected into mice which had previously undergone freeze-damaging of individual muscles. In agreement with our hypothesis, intense labelling was observed in the muscle, specifically in damaged regions. Second, the technique was adapted to meet the needs of chronic diseases with characteristic continuous, widespread degeneration of muscle fibers, by creating a reservoir of genetically engineered monocytes, via bone marrow transplantation. Mdx mice received bone marrow from transgenic mice expressing the lacZ reporter gene, under the control of the vimentin promoter, which is active in monocytes and macrophages. Histological and molecular analyses demonstrated the homing of engineered macrophages at the sites of muscle damage, for periods as long as 2 months. Bone marrow progenitor cells, appropriately engineered to elicit the synthesis, in macrophages, of therapeutically relevant substances, may be of clinical value in various pathologies involving an inflammatory phase.

Animals↗

PubMed1996

[Cost-effectiveness of and morbidity from digital subtraction angiography. A study of 5,817 cases].

This study was based on 5,817 patients examined by digital subtraction angiography (DSA) between 1984 and 1990. 5,209 patients received an intravenous injection of contrast agent and 608 received an intra-arterial injection. Digital subtraction angiography has become a routine procedure for the diagnosis of vascular disease in the various fields studied, as it provides images of diagnostic quality in 97% of cases: diagnostic quality of 95% after intravenous injection and 99% after intra-arterial injection. The morbidity is 1.65% for the intravenous route and 4.8% for the intra-arterial route. The morbidity of brachial artery catheterization is 5.5% DSA by intravenous injection is a low-risk angiographic technique which represents a major economy in terms of the cost of the examination and the examination time, a reduction of hospital stay and waiting lists; these advantages are very important in the current context of public health.

Adolescent↗

PubMed1996

Comparison of the clinical anticaries efficacy of an 1100 NaF silica-based dentifrice containing triclosan and a copolymer to an 1100 NaF silica-based dentifrice without those additional agents: a study on adults in California.

Recent years have seen much work in the development of dentifrices containing the antimicrobial agent triclosan, a broad spectrum antibacterial agent manufactured for use in oral products by the Ciba-Geigy Corporation. Studies have shown that the incorporation of this agent into dental products, in combination with a PVM/MA copolymer (the non-proprietary designation for a polyvinylmethyl ether/maleic acid copolymer), can provide several important dental therapeutic benefits, including an antigingivitis effect. Much research on the therapeutic benefits of such dentifrices has been reported in the literature. The present study is a component of a large-scale program of clinical research to investigate the anticaries effectiveness of fluoride dentifrices containing 0.3% triclosan and 2.0% PVM/MA copolymer. The study included two treatment groups, each consisting of adults living within a 50 mile radius of Loma Linda, California, who were assigned to the use of one of the following sodium fluoride (NaF) dentifrices: 1) a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.243% NaF/silica (1100 ppm F) base; or 2) a dentifrice containing 0.243% NaF/silica (1100 ppm F). Conducted in accordance with the guidelines for caries clinical studies published by the Council on Dental Therapeutics of the American Dental Association, the study employed clinical diagnostic criteria as described in the August, 1987 National Institute of Dental Research (NIH/NIDR) publication. Dental radiographs were not employed. Principal comparisons of the dentifrices tested were implemented through the construction of 90% confidence intervals for the ratio of mean 3-year caries increments, using Fieller's theorem. Of those subjects who met the initial inclusion/exclusion criteria for this study, 1,542 were available for the 36-month examination. DFS (resp., DFT) increments over this period were 2.07 (0.63) for the triclosan/copolymer dentifrice, and 2.16 (0.68) for the dentifrice without those additives. The confidence interval calculations for both incremental DFS and DFT support the conclusion that a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.243% NaF/silica (1100 ppm F) base provides a level of anticaries efficacy which is "at least as good as" that provided by a dentifrice containing 1100 NaF/silica without those additive agents. As such, the results of this clinical study clearly indicate that the addition of triclosan and a copolymer to a 1100 NaF/silica dentifrice does not compromise its anticaries efficacy.

Adult↗

PubMed1996

Comparison of the clinical anticaries efficacy of a 1500 NaF silica-based dentifrice containing triclosan and a copolymer to a 1500 NaF silica-based dentifrice without those additional agents: a study on adults in Israel.

Recent years have seen much work in the development of dentifrices containing the antimicrobial agent triclosan, a broad spectrum antibacterial agent manufactured for use in oral products by the Ciba-Geigy Corporation. Studies have shown that the incorporation of this agent into dental products, in combination with a PVM/MA copolymer (the non-proprietary designation for a polyvinylmethyl ether/maleic acid copolymer), can provide several important dental therapeutic benefits, including an antigingivitis effect. A considerable amount of the research on the therapeutic benefits of such dentifrices has been reported in the literature. The present study is a component of a large-scale program of clinical research to investigate the anticaries effectiveness of fluoride dentifrices containing 0.3% triclosan and 2.0% PVM/MA copolymer. The study included two treatment groups, each consisting of adults living near the Kiryat Gat area in Israel, who were assigned to the use of one of the following sodium fluoride (NaF) dentifrices: 1) a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.331% NaF/silica (1500 ppm F) base; or 2) a dentifrice containing 0.331% NaF/silica (1500 ppm F). Conducted in accordance with the guidelines for caries clinical studies published by the Council on Dental Therapeutics of the American Dental Association, the study employed clinical diagnostic criteria as described in the August, 1987 National Institute of Dental Research (NIH/NIDR) publication. Dental radiographs were not employed. Principal comparisons of the dentifrices tested were implemented through the construction of 90% confidence intervals for the ratio of mean 3-year caries increments using Fieller's Theorem. Of those subjects who met the initial inclusion/exclusion criteria for this study, 1,296 were available for the 36-month examination. DFS (resp., DFT) increments over this period were 5.21 (1.30) for the triclosan/copolymer dentifrice, and 5.23 (1.39) for the dentifrice without those additives. The confidence interval calculations for both incremental DFS and DFT support the conclusion that a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.331% NaF/silica (1500 ppm F) base provides a level of anticaries efficacy which is "at least as good as" that provided by a dentifrice containing 1500 NaF/silica, without those additive agents. As such, the results of this clinical study clearly indicate that the addition of triclosan and a copolymer to a 1500 NaF/silica dentifrice does not compromise its anticaries efficacy.

Adult↗

PubMed1995

Myotube driven myogenic recruitment of cells during in vitro myogenesis.

Muscular dysgenesis (mdg) is a recessive lethal mutation in the mouse which drastically affects skeletal muscle development during embryonic life. Physiologically, the disease is characterized by a complete paralysis resulting from a lack of excitation-contraction coupling. Existing electrophysiological, biochemical, and genetic evidence shows that mdg/mdg mice express a basic alteration of L-type voltage-sensitive Ca2+ channels in skeletal muscle. Studies on mdg/mdg myotubes in primary culture have shown that +/+ fibroblasts or +/+ Schwann cells may fuse with them and correct their functional deficiency by genetic complementation. As the spontaneous formation of heterocaryons is thought to be an exclusive property of myoblasts, we asked whether fibroblasts may have changed their properties before fusion occurred. We used primary cells issued from sciatic nerves dissected from newborn transgenic mice carrying the pHuDes1-nls-LacZ transgene (Des-LacZ cells) as non-muscle cells. These cells were mainly fibroblasts (80%) positive for Thy1.1 and Schwann cells positive for S100. The cultures were negative for myogenic markers (desmin, troponin T), did not form myotubes long-term, and did not display significant activation of the muscle reporter gene (pHuDes1-nls-LacZ). After a few days in coculture with dysgenic or normal myotubes, the muscle reporter gene (beta-galactosidase) was detected both within dysgenic myotubes, correlating with the restoration of normal contractile activity, and normal myotubes. As well as confirming that fusion takes place, this shows that Des-LacZ cells nuclei incorporated into recipient myotubes express their own myogenic genes. Moreover, individual mononucleated Des-LacZ cells expressing beta-galactosidase were observed, indicating that myogenic genes were being expressed before fusion. This suggests a mechanism of myotube driven myogenic recruitment of cells during the in vitro myogenesis. Analysis of the distribution of the induced Des-LacZ cells (positive for beta-galactosidase) in compartmentalized muscle cocultures showed that in the presence of dysgenic myotubes, these cells were equally distributed in both myotube free and enriched areas, whereas in the presence of normal myotubes, the positive cells remained in close vicinity of the myotubes. This difference could be explained by the fact that the dysgenic phenotype might include release of the induction process from its normal controls. Our results are consistent with the idea of a transcellular mechanism triggering myogenic differentiation in non-muscle cells, and that myotubes themselves are able to drive myogenic recruitment of cells during the in vitro myogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Osteochondroma of the peroneal tubercle. A report of two cases.

We report two patients with pain on the lateral side of the ankle and foot which was due to stenosing tenosynovitis of the peroneal tendons caused by an osteochondroma of the peroneal tubercle. Surgical treatment produced a good result in both cases. The condition is uncommon, but should be borne in mind as a possible cause of pain in this region.

Adult↗

PubMed1995

Recording of a large-conductance chloride channel in normal rat lactotrophs.

Membrane current fluctuations resembling channel openings and closings were observed in the whole cell configuration of the patch-clamp technique in normal rat lactotrophs in primary culture. Using high-gain head stage in whole cell configuration, we characterized the nature and pharmacological properties of the ionic channel underlying these fluctuations. This channel, found in small numbers (< 10 per cell), was specific for Cl- because its reversal potential varied with Cl- gradients, according to the Nernst equation, and its unitary amplitude was linearly related to membrane potential from -100 to 0 mV. Slope conductance was close to 100 pS. Analyzing open times, we demonstrated its Ca2+ and potential dependence. Four sublevels were observed. We suggest that this channel, belonging to the background Cl- channel group, takes part in the regulation of intracellular Cl- concentration of normal rat lactotrophs.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed1995

Actual pentamidine dose delivered by Respigard II nebulizer.

The Respigard II nebulizer system is the approved method to deliver pentamidine aerosols in the USA. Although continuous operation of the nebulizer until dryness is a designated regimen, the actual pentamidine dose delivered under the operating condition has not been thoroughly studied. Pentamidine solutions (300 mg in 6 mL water) were nebulized continuously with the Respigard II nebulizer system until dryness (40 min operation). Aerosols were delivered to the lower airways via an oropharyngeal model and sampled on a filter with a standard breathing mode of 20 breaths.min-1 frequency and 750 mL tidal volume. Intermediate samples were also obtained for the initial 20 min delivery. The pentamidine dose delivered to the mouth was 1.6% of the dose placed in the nebulizer. Of the dose delivered to the mouth, 92% was delivered during the initial 20 min period. Aerosol loss in the oropharyngeal model was 15% of the dose delivered to the mouth or 0.24% of the dose initially placed in the nebulizer. Pentamidine dose delivered to the lower airways was a very small fraction of the initial dose in the nebulizer. A partial delivery for the initial 20 min was nearly comparable to complete delivery.

Humans↗

PubMed1995

Enhanced anticaries efficacy of a 0.243% sodium fluoride/10% xylitol/silica dentifrice: 3-year clinical results.

PURPOSE: To evaluate the efficacy of a sodium fluoride (NaF)/silica/xylitol dentifrice compared with that of a positive control NaF/silica dentifrice on caries increments in school children over a 3-year period in an area without an optimal level of fluoride in the drinking water (mean level <0.1 ppm). MATERIALS AND METHODS: A 3-year, double-blind clinical caries study was conducted in 2,630 children initially aged 8-10 years at 17 schools in the San Jose, Costa Rica metropolitan area. Clinical dental examinations were performed at participating schools utilizing portable dental equipment. Caries evaluations employed conventional tactile/visual methodology consisting of artificial light, dental mirrors and single-edge #23 explorers. Children accepted into the study were stratified by age and sex into two balanced groups within each school, and randomly assigned to use either a positive control dentifrice containing 0.243% NaF/silica or a test dentifrice containing 0.234% NaF/silica/10% xylitol. Children were instructed to brush with the assigned dentifrice twice daily. Caries evaluations were conducted at baseline, 2 years, and 3 years. RESULTS: After 3 years, subjects using the 0.234% NaF/silica/10% xylitol dentifrice had statistically significantly reduced decayed/filled surfaces (DFS; -12.3% reduction; P < or = 0.001) and decayed/filled buccal and lingual surfaces (DFS-BL; -10.5% reduction; P < or = 0/01).

Cariostatic Agents↗

PubMed1994

Stable expression of human H1-histamine-receptor cDNA in Chinese hamster ovary cells. Pharmacological characterisation of the protein, tissue distribution of messenger RNA and chromosomal localisation of the gene.

A cDNA clone for the histamine H1 receptor was isolated from a human lung cDNA library; it encoded a protein of 487 amino acids which showed characteristic features of G-protein-coupled receptors. The percentages of identity of the deduced amino acid sequence with bovine, rat and guinea pig H1 histamine receptors were 82.6%, 79.4% and 73.3%, respectively, whereas these percentages decreased to 74.6%, 66% and 56.7% for the amino acid sequence of the third intracellular loop. The human H1-receptor cDNA was transfected into Chinese hamster ovary cells (CHO) via an eukaryotic expression vector; the receptor protein present on cell membranes specifically bound [3H]mepyramine with a Kd of 3.7 nM. The binding was displaced by H1-histamine-receptor antagonists and histamine. Northern blot analysis indicated the presence of two histamine H1 receptor mRNAs of 3.5 kb and 4.1 kb in various human tissues and an additional mRNA of 4.8 kb restricted to the human brain. Finally, by means of somatic cell hybrids segregating either human or rat chromosomes, the gene for histamine H1 receptor was found to reside on human chromosome 3 and rat chromosome 4.

Amino Acid Sequence↗

PubMed1994

Restoration of normal ultrastructure after expression of the alpha 1 subunit of the L-type Ca2+ channel in dysgenic myotubes.

Muscular dysgenesis (mdg) is a spontaneous mutation affecting the alpha 1 subunit of the skeletal L-type Ca2+ channel. mdg/mdg mice suffer from a skeletal muscle disease characterised by low levels of the slow Ca2+ current, lack of contractile activity, and immature organisation of skeletal muscle. Microinjections of a cDNA encoding alpha 1 into mutant myotubes restore excitation-contraction coupling. We checked here that dysgenic myotubes transfected with expression vectors, including a full-length alpha 1 cDNA, also recover normal ultrastructural features. Transfection of alpha 1 cDNA partially deleted on the 5' end leads to the recovery of a good structural organisation without any improvement in the mutant physiological phenotype. These results suggest that: (i) the proper expression of alpha 1 is required for the full muscle differentiation of muscular dysgenesis myotubes, and (ii) portions of the alpha 1 molecule may be involved in the structural organisation of a muscle fiber, independent of its known functional properties.

Animals↗

PubMed1994

Hunger in California: what interventions are needed?

OBJECTIVE: Although research exists on the nutritional status of individuals and families who seek emergency food, there is little guidance on what to do about it. Our purpose was to develop effective nutrition interventions to assist individuals and families seeking emergency food. DESIGN AND SUBJECTS: Two survey instruments were used to collect data on 697 emergency food providers and 3,365 emergency food clients in 20 California counties between 1986 and 1990. STATISTICAL ANALYSES PERFORMED: Data were analyzed using the Statistical Package for the Social Sciences. RESULTS: Information from the food providers who staff the emergency food sites revealed insufficient food to meet the growing demand, client difficulties in using the donated food, and the need for information to improve the safety and nutritional quality of the donated food. Information from the emergency food clients documented that 70.4% of them were families with children, 84% had incomes below the poverty level, and 20% reported no income at all. In addition, most clients (70%) were not enrolled in the food stamp program. APPLICATIONS/CONCLUSIONS: In response to the surveys, counties initiated a variety of interventions, including public awareness campaigns, community development activities, and nutrition education programs. Important strategies are to teach recipients ways to optimize food resources, encourage eligible individuals to enroll in federal nutrition programs, and link individuals with agencies that offer assistance.

California↗

PubMed1994

Red cell loss following orthopedic surgery: the case against postoperative blood salvage.

BACKGROUND: Expensive devices have been developed for the collection and transfusion of blood salvaged after hip or knee arthroplasty. STUDY DESIGN AND METHODS: The volume of salvaged red cells was measured for the first 6 hours after operation. This volume was compared to total red cell loss during hospitalization and to the volume of allogeneic red cells transfused. RESULTS: Mean postoperative red cell loss in 31 patients following hip replacement was 55 +/- 29 mL and that in 20 patients following knee replacement was 121 +/- 50 mL. The 6-hour wound drainage represented 8.7 and 16.8 percent of overall red cell loss during hospitalization for hip and knee replacement, respectively. The transfusion of postoperatively salvaged red cells would have supplanted transfusion of less than one-third of a unit of allogenic blood after hip replacement and two-thirds of a unit after knee replacement. Only three patients (5.9%) lost red cell volume in the drainage equivalent to or in excess of 1 unit of red cells (180 mL). The volume of red cells salvaged postoperatively bore no relationship to perioperative red cell losses as a whole. CONCLUSION: The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique for the recovery of autologous blood.

Aged↗

PubMed1994

Thoracic disc herniation, cord compression, and paraplegia caused by electrical injury: case report and review of the literature.

The case of a patient with thoracic intervertebral disc prolapse, cord compression, and delayed paraplegia with recovery secondary to high-tension electrical current is presented. The unusual entry wound in the neck, makes this a rare event that to our knowledge has not been previously described in the literature. Magnetic resonance imaging allowed noninvasive and early diagnosis, and in the future probably will reveal the true incidence of cord compression in electrical injury victims.

Adult↗

PubMed1994

Melanocyte reservoir in vitiligo.

BACKGROUND: Dopa-negative, inactive melanocytes, present in the middle portion of the hair follicle, but also in hair bulbs, have been reported as a source of pigment cells, when repopulation of epidermal melanocytes occurs. A melanocyte reservoir in these anatomical sites has been suggested. Our objective was to investigate the ability of the lower third of the hair follicle (hair bulb) to repigment achromic skin in vitiligo. METHODS: Scalp hair bulbs were transplanted within leukodermic areas in 10 patients with vitiligo. RESULTS: Repigmentation around the grafts was suitable for evaluation in four cases. Dopa-positive (+) cells were seen in the epidermal basal cell layer of the repigmented areas. CONCLUSIONS: Although these findings were observed only in a few patients, they suggest that melanocytes from the implanted lower third portion of the hair follicle (hair bulb) act as a reservoir in this anatomic location and are able to migrate and repigment achromic areas in vitiligo.

Adult↗