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R Garcia

Publications and source records attributed to R Garcia.

At least 37 records · Page 2Linked to original sources
PubMed2004

Lectin receptors for endometrial H-type 1 antigen on goat conceptuses.

PROBLEM: The goal of this study was to determine if caprine conceptuses express lectin-like receptors for endometrial H-type 1 (HT1) antigen. METHOD OF STUDY: Conceptus tissues were collected during the apposition, adhesion and attachment phases of placentation and evaluated using immunofluorescence microscopy. RESULTS: Conceptus staining for the trisaccharide lacto-N-fucopentaose-1 was strong and uniform during apposition of fetal and maternal tissues but changed by day 25 of pregnancy when large aggregates of intense staining were observed. Monoclonal antibodies to galectin-3 did not stain conceptus tissue during the apposition phase but intense punctate staining was observed after day 25. Strong uniform staining for Lewis Y antigen was detected only on day 17 of pregnancy. CONCLUSION: Conceptus tissue expresses potential receptors for endometrial HT1 antigen. Carbohydrate-lectin interactions may facilitate attachment of the apical surfaces of uterine epithelial cells and trophectoderm during the early stages of placentation.

Animals↗
PubMed2004

[Recommendations in the use of portal images].

Technical radiotherapy progress drive the practices towards increasingly more precise irradiations. The recent developments of the various imaging methods and specialized software made more controls possible. The fields of investigations relate to the quality assurance of the irradiation, the reproducibility of positioning, the movements evaluations and real time dosimetry. Radiotherapy finds, in the images exploitation, a strong potential in improving quality treatments, however it is conditioned by the implementation of ambitious programs, time consuming, but essential to grant the precision of virtual simulations and the daily practice. If all the existing technical devices and software offer higher tools than the current practices, the recommendations can be limited to the insurance of a sufficient precision and reproducibility of the whole treatments. It is thus fundamental to be able to filter the errors, the systematic deviations and to control the statistics of positioning and movements. Each radiotherapy department must apply an adapted program to each site and exploit the imaging chain to maintain its results.

Humans↗
PubMed2003

Critical adsorption in a well-defined geometry.

A fluid's density profile near a wall is predicted to assume a universal shape near the liquid-vapor critical point, a phenomenon termed critical adsorption. This universal shape is predicted to depend on the boundary conditions of the fluid at the walls and is predicted to be a function of the ratio z/xi, where z is the distance from the wall and xi is the bulk correlation length. A body of evidence confirms the analogous phenomenon of critical adsorption in binary fluids near the critical demixing point, but in the simple liquid-vapor system the experimental situation is not as clear. For example, critical adsorption of SF6 was observed in porous glass for reduced temperature t=T/T(c)-1>10(-3). However, for t<10(-3) a desorption behavior is seen. This desorption has so far resisted rigorous theoretical explanation. We report measurements of the critical adsorption of nitrogen inside a capacitor gap with a simple parallel plate geometry and open gap of 3 microm. Unlike the previous experiments with SF6, the data show a monotonic increase in the adsorption between t=5 x 10(-4) and t=10(-6), consistent with theoretical prediction and without any indication of desorption.

Journal Article↗
PubMed2003

Economic costs associated with inadequate drug prescribing: an exploratory study in Chiapas, Mexico.

An exploratory study assessing the economic consequences of inadequate prescribing by health-care providers was carried out in two cities of Chiapas State, South Mexico. Two research methods were used: (a) an exit survey with pharmacy users (1190 interviews) and (b) in-depth individual interviews with patients at hospital level (19 interviews). For comparative purposes, three tracer conditions were selected: acute respiratory infection (ARI), diarrhoeal disease (DD) and hypertension. The main findings were that doctors, drug vendors at pharmacies, traditional healers, users of health-care services themselves (through self-prescription) and other health staff are all sources of inadequate prescribing and impose a substantial economic burden of unnecessary cost on health-care users. In general, treatment costs were high compared with standard treatments, and prescriptions included a high proportion of non-essential drugs (50-64%). Additional costs to the standard treatment were particularly high when the prescription was by a medical doctor (US$ 3.57 per ARI prescription and US$ 8.37 for DD). Losses attributable to inadequate prescribing averaged US$ 47 per patient. The study concludes that training programmes on rational drug use aimed exclusively at medical doctors can only have a limited effect in reducing economic losses due to inadequate prescribing. Such efforts should be extended to other providers who are very active in prescribing drugs and providing health advice. The main challenge that the Mexican health system will be facing in the foreseeable future is not only to improve equity of access to essential drugs, but also to improve quality of drug advice and prescription and rational use of drugs by the population.

Adult↗
PubMed2003

Safety and efficacy of sirolimus in kidney transplant patients and in patients with coronary artery disease undergoing angioplasty.

UNLABELLED: We show the key results of our 4-year experience with sirolimus in kidney transplant patients and in nontransplanted patients undergoing coronary angioplasty. METHODS: Recipients of one-haplotype living-related kidney allografts were randomized to receive sirolimus (2 mg/d, n = 35) or azathioprine (2 mg/kg per day, n = 35). Recipients of fully mismatched living kidney allografts (n = 55) received sirolimus (2 mg/day). High-risk recipients of black ethnicity (n = 68) were randomized to target whole-blood trough sirolimus concentrations between 8 and 12 ng/mL or 15 to 20 ng/mL. All kidney transplant patients received cyclosporine and prednisone. Sirolimus/cyclosporine pharmacokinetic studies were performed in 40 patients receiving 2 mg (n = 20) or 5 mg (n = 20) of sirolimus 7 days after transplantation. In the coronary intervention study, 12 patients at high risk for in-stent restenosis received sirolimus for 28 days after angioplasty. RESULTS: The incidence of biopsy-confirmed acute rejection was 11.4% in recipients of one-haplotype living-related kidney allografts, 16.4% in recipients of fully mismatched living kidney allografts, and 15% (8 to 12 ng/mL) and 4% (15 to 20 ng/mL) in high-risk recipients of black ethnicity. Cyclosporine exposure was higher after morning administration compared to evening administration. There were poor correlations between sirolimus and cyclosporine exposures. The 4-month follow-up angiography revealed no restenosis (stenosis diameter > 50%), a late loss of 0.56 +/- 0.40 mm, and a loss index of 0.33 +/- 0.30. The follow-up 3D-intravascular ultrasound restudy showed an in-stent relative volumetric obstruction of 9.9 +/- 5.5%. Sirolimus in highly effective in preventing kidney allograft acute rejection and in-stent coronary restenosis.

Adult↗
PubMed2003

Assessment of tin and butyltin species in estuarine superficial sediments from Gipuzkoa, Spain.

Ten superficial sediments from river estuaries of Gipuzkoa (North Spain) were collected and analyzed for nine metals (including tin, Sn) and butyltin compounds (monobutyltin, MBT; dibutyltin, DBT; tributyltin, TBT). Total metal concentration in the fine fraction (<63 micrometer) of the sediment was determined in aqua regia--hydrofluoric acid extracts by atomic absorption spectrometry. The butyltin species (BTs) were firstly extracted from the sediments with hydrochloric acid-methanol mixture. After derivatization with sodium tetraethyl borate, the organotin compounds were extracted by solid phase microextraction (SPME) in headspace mode. A fiber coated with 100 micrometer poly(dimethylsiloxane) was used for SPME. The organotin species were analyzed by gas chromatography-flame ionization detection. Analysis of the certified reference sediment (PACS-2) shown the suitability of the procedures for determination of metal contents and DBT-TBT species in contaminated sediments. Factorial analysis was used to examine the main sources of metals. Three factors represented more than 89% of the total variance of the metal system, and the Sn was related with Cu-Zn-Pb suggesting the same pollution source. The BTs concentrations in the area were high (TBT ranged from 0.05 to 5.48 mg Sn kg(-1)). The percentage of total butyltin species ( summation operator BTs) respect to the total Sn amount was higher than 4% in all the sediments, showing in the Bidasoa river estuary a remarkable value higher than 20%. Hence, the studied estuarine sediments reflect a pollution that is related with historical industrial and fishing activities of the area.

Environmental Monitoring↗
PubMed2003

Hypogalactosylation of serum IgG in patients with coeliac disease.

Coeliac disease (CD) is described as an autoimmune enteropathy associated with the presence of IgG and IgA antigliadin and antitransglutaminase autoantibodies. While of diagnostic significance, the role of these autoantibodies in the immunopathogenesis of CD is elucidated. An inappropriate T cell immune response to gluten is also involved in the pathogenesis of CD, as evidenced by autoantibody switching. The N-glycans released from serum IgG of CD patients and three groups of healthy controls, of differing age ranges, were analysed by NH2-high performance liquid chromatography (HPLC). The fucosylated biantennary N- glycans were the most abundant neutral oligosaccharides; in particular, the agalacto form (G0F) showed a mean value of 42% (s.d. +/- 7.4), 30% (s.d. +/- 5.9), 26% (s.d. +/- 4.2) and 35% (s.d. +/- 6.8) for CD patients, healthy children, healthy adults under 40 and healthy adults over 40 years old, respectively. The ratio of asialo agalacto fucosylated biantenna to asialo monogalacto fucosylated biantenna (G0F)/(G1F) for CD patients showed a significant increase compared to healthy children (P < 0.0002), healthy adults under 40 (P < 0.0002) and healthy adults over 40 years old (P < 0.01). Hypogalactosylation was more pronounced for CD patients than for the patients with other autoimmune diseases such as rheumatoid arthritis or psoriatic arthritis.

Adult↗
PubMed2003

First report of Siphonaptera infesting Microtus (Microtus) cabrerae (Rodentia-Muridae-Arvicolinae) in Cuenca, Spain and notes about the morphologic variability of Ctenophthalmus (Ctenophthalmus) apertus personatus (Insecta-Siphonaptera-Ctenophthalmidae).

The fleas infesting Microtus (Microtus) cabrerae from three different areas of Cuenca province (Spain) have been studied. It is the first time that on ectoparasitological study of this badly known rodent has been done. Four Siphonaptera species have been detected: Rhadinopsylla (Actenophthalmus) pentacantha, Peromyscopsylla spectabilis spectabilis, Nosopsyllus fasciatus and Ctenophthalmus (Ctenophthalmus) apertus personatus, which was the most abundant species (26 males and 31 females of a total of 28 males and 35 females). Considering the great morphologic variability within the male processus basimerus ventralis (p.b.v.) of segment IX of C. personatus subspecies, three morphotypes have been recognised. The male polymorphism detected, would be the result of both host confinement and genetic selection acting on the parasite. It should be pointed out that C. (C.) apertus personatus is not narrowly host-specific, therefore further studies are required to clarify this taxonomic situation.

Animals↗
PubMed2003

[Respiration-gated radiotherapy: current techniques and potential benefits].

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart...) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath hold techniques or respiration synchronized gating techniques. Breathhold techniques can be achieved with active, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-hold. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. These techniques presently investigated in several medical centers worldwide. Although promising, the first results obtained in lung and liver cancer patients require confirmation. Physical, technical and physiological questions still remain to be answered. This paper describes the most frequently used gated techniques and the main published clinical reports on the use of respiration-gated radiotherapy in order to evaluate the impact of these techniques.

Breast Neoplasms↗
PubMed2002

Critical Casimir effect near the (3)He-(4)He tricritical point.

We present capacitance measurements of the equilibrium thickness of (3)He-(4)He mixture films as a function of temperature and concentration. The films are adsorbed on a Cu substrate situated above bulk liquid mixture. As we scan across the tricritical point, we observe a thickening of the film indicating the presence of a repulsive critical Casimir force.

Journal Article↗
PubMed2002

Optimal hand locations for safe scaffold-end-frame disassembly.

Overexertion and fall injuries comprise the largest category of injuries among scaffold workers. A significant portion of these injuries is associated with scaffold-end-frame dismantling tasks, which require both muscle strength and postural balance skills. The commonly used tubular scaffold end frame is 1.52-m wide x 2-m high and weighs 23 kg. Previous studies have indicated that a great muscle strength can be generated when scaffold workers placed their hands symmetrically at knuckle height. However, adequate postural stability can only be reached when the workers placed their hands at the chest or shoulder height, which is near to the height of scaffold-end-frame center-of-mass. A reasonable approach to solve this dilemma is to develop an assistive lifting device, such as a light-weight clip-and-lift bar, that allows workers to place their hands at the height of the center-of-mass of end frames and concurrently allows an optimal hand separation for them to generate an adequate maximum isometric muscle force to safely accomplish the task. This study was conducted to determine the optimal hand location for a conceptual assistive lifting device to mitigate potential postural imbalance while reducing overexertion hazards during scaffold disassembly. This location would be within a window defined by a vertical hand placement between shoulder height and knuckle height and by a horizontal hand separation distance of shoulder width to end-frame width. The whole-body maximum isometric strength of 54 construction workers was measured in nine symmetric scaffold-end-frame disassembly postures, defined by a combination of three vertical hand placements by three horizontal hand separation distances within the aforementioned window. The study apparatus include a computer-controlled data-acquisition system, a custom-fabricated scaffold fixture, and two Bertec force platforms. An analysis of variance showed that the interaction effect of vertical hand placement and hand separation on workers' maximum isometric strength was significant (p < 0.004). A hand location between elbow height and chest height with a hand separation distance of 46 cm (a conceptual, light-weight assistive bar) would allow workers to generate sufficient isometric strength (about twice that of the scaffold weight) to disassemble the typical 23 kg scaffolds while concurrently allowing them to mitigate the likelihood of postural imbalance.

Accidental Falls↗
PubMed2002

[Radiotherapy of lung cancer: the inspiration breath hold with spirometric monitoring].

A CT acquisition during a free breathing examination generates images of poor quality. It creates an uncertainty on the reconstructed gross tumour volume and dose distribution. The aim of this study is to test the feasibility of a breath hold method applied in all preparation and treatment days. Five patients received a thoracic radiotherapy with the benefit of this procedure. The breathing of the patient was measured with a spirometer. The patient was coached to reproduce a constant level of breath-hold in a deep inspiration. Video glasses helped the patients to fix the breath-hold at the reference level. The patients followed the coaching during preparation and treatment, without any difficulty. The better quality of the CT reconstructed images resulted in an easier contouring. No movements of the gross tumour volume lead to a better coverage. The deep breath hold decreased the volume of irradiated lung. This method improves the reproducibility of the thoracic irradiation. The decrease of irradiated lung volume offers prospects in dose escalation and intensity modulation radiotherapy.

Aged↗
PubMed2002

[Thoracic radiotherapy and control of respiration: current perspectives].

Three-dimensional conformal radiotherapy (3D CRT) is adversely affected by setup error and organ motion. In thoracic 3D CRT, breathing accounts for most of intra-fraction movements, thus impairing treatment quality. Breath control clearly exhibits dosimetric improvement compared to free breathing, leading to various techniques for gated treatments. We review benefits of different breath control methods--i.e. breath-holding or beam gating, with spirometric, isometric or X-ray respiration sensor--and argument the choice of expiration versus inspiration, with consideration to dosimetric concerns. All steps of 3D-CRT can be improved with breath control. Contouring of organs at risk (OAR) and target are easier and more accurate on breath controlled CT-scans. Inter- and intra-fraction target immobilisation allows smaller margins with better coverage. Lung outcome predictors (NTCP, Mean Dose, LV20, LV30) are improved with breath-control. In addition, inspiration breath control facilitates beam arrangement since it widens the distance between OAR and target, and leaves less lung normal tissue within the high dose region. Last, lung density, as of CT-scan, is more accurate, improving dosimetry. Our institution's choice is to use spirometry driven, patient controlled high-inspiration breath-hold; this technique gives excellent immobilization results, with high reproducibility, yet it is easy to implement and costs little extra treatment time. Breath control, whatever technique is employed, proves superior to free breathing treatment when using 3D-CRT. Breath control should then be used whenever possible, and is probably mandatory for IMRT.

Artifacts↗
PubMed2002

Levonorgestrel implants (Norplant II) for male contraception clinical trials: combination with transdermal and injectable testosterone.

Recent studies demonstrate that combinations of androgens and progestagens are highly effective in the suppression of spermatogenesis in normal volunteers. To test whether progestagen and androgen delivery systems designed to produce steady serum levels will be as effective as other androgen plus progestagen combinations, we compared Norplant II and testosterone (T) transdermal patch to T patch alone on the suppression of spermatogenesis in normal men. Thirty-nine healthy male volunteers (age, 20-45 yr) were randomly assigned to one of two groups. Group 1 (n = 19) received two transdermal T patches daily (Testoderm TTS, each patch designed to deliver about 5 mg/d T) alone, and group 2 (n = 20) received combined Norplant II [Jadelle, four capsules delivering approximately 160 microg/d levonorgestrel (LNG)] plus T patch. Neither of these regimens were very effective, with suppression of spermatogenesis to severe oligozoospermia occurring in less than 60% of subjects. We then expanded the study to include two more groups to determine whether T patch or Norplant II was the main factor causing the inadequate suppression of spermatogenesis. Another 29 subjects were randomized to one of two groups. Group 3 (n = 15) received oral LNG (125 microg/d) plus T patch, and group 4 (n = 14) received Norplant II plus T enanthate (TE) injection (100 mg/wk i.m.). After a pretreatment phase of 4 wk, all subjects received treatment for 24 wk, followed by a recovery period of 12-24 wk. Steady-state serum LNG levels (800-1200 pmol/liter) were achieved from wk 3-24 after Norplant II insertion and decreased rapidly after the removal of the implants at wk 24. Trough serum LNG levels after oral LNG administration were at a comparable range (940-1300 pmol/liter). Azoospermia was achieved in 24%, 35%, 33%, and 93%, and severe oligozoospermia (<1 x 10(6)/ml) developed in 24%, 60%, 42%, and 100% of the subjects in groups 1, 2, 3, and 4, respectively, during treatment phase. All subjects in the Norplant II plus TE groups had persistent sperm concentrations less than 3 x 10(6)/ml from wk 12 until the end of treatment. Concomitant with the marked suppression of spermatogenesis in the Norplant II plus TE group, serum FSH and LH levels were most decreased in this group compared with all other groups. In the T patch-only group, serum SHBG was not suppressed, and total serum T was higher than baseline levels. In the other three groups administered progestagens, serum SHBGs were significantly suppressed, and serum total T remained similar to baseline levels. Serum free T levels were not changed in any group. Except for a suppression of serum high-density lipoprotein cholesterol, there was no significant change in weight, hematocrit, clinical chemistry, or prostate-specific antigen levels in any of the treatment groups. Although more efficacious than T patch alone, Norplant II or oral LNG plus T patch was not as effective in suppressing spermatogenesis to severe oligo- or azoospermia as in previous reports using oral LNG plus TE. This relative lesser efficacy occurred despite the achievement of serum LNG levels by Norplant II that were equivalent to those reported after administration of oral LNG. Substituting the transdermal T delivery system with TE injections resulted in very effective suppression of sperm output. The difference in spermatogenesis suppression of these combined regimens is likely due to less T delivered by the transdermal patch compared with the TE weekly injections. We conclude that Norplant II implants plus TE 100 mg/wk were very efficient in suppressing spermatogenesis to a level acceptable for contraceptive efficacy. This study demonstrates that the dose or route of administration of androgens is critical for sperm suppression in combined androgen-progestagen regimens for hormonal male contraception.

Administration, Cutaneous↗
PubMed2001

Efficacy after sequencing of brain radiotherapy and enhanced antibody targeted chemotherapy delivery in a rodent human lung cancer brain xenograft model.

PURPOSE: The objective of this study was to evaluate the efficacy of sequencing radiation therapy (RT) and antibody targeted chemotherapy (BR96-DOX) in nude rats bearing human lung cancer (B.5 LX-1) intracerebral (i.c.) xenografts. METHODS AND MATERIALS: Our approach was to administer RT using 20 Gy single-fraction cranial irradiation either before, concurrent with, or after BR96-DOX treatment via osmotic blood-brain barrier disruption to enhance immunoconjugate delivery. All rats were inoculated with i.c. B.5 LX-1 tumors and were randomly assigned to treatment groups. RESULTS: BR96-DOX alone on Day 6 or Day 12 significantly increased survival compared to negative control rats receiving no treatment (25.9 +/- 2.1 and 23.3 +/- 2.5 days vs. 14.8 +/- 1.9 days, p < 0.05). Rats that received chemotherapy before radiation (34.0 +/- 2.0 days) lived the longest compared to the other sequences (RT prior, 29.5 +/- 1.9; RT concurrent, 27.1 +/- 2.1). Histopathology of 39 rat brains did not reveal any neuropathology. CONCLUSIONS: Enhanced delivery of immunoconjugates is more effective in combination with RT for the treatment of experimental metastatic brain tumors. Moreover, BR96-DOX administration prior to RT significantly increased survival compared to those receiving RT and chemotherapy concurrently (p < 0.05).

Animals↗