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Biomedical subjects

V Lopez

Publications and source records attributed to V Lopez.

At least 19 recordsLinked to original sources
PubMed2006

A Chinese Mandarin translation and validation of the Myocardial Infarction Dimensional Assessment Scale (MIDAS).

AIMS: To evaluate the validity, reliability, and cultural relevance of the Chinese Mandarin version of Myocardial Infarction Dimensional Assessment Scale (MIDAS) as a disease-specific quality of life measure. METHODS: The cultural relevance and content validity of the Chinese Mandarin version of the MIDAS (CM-MIDAS) was evaluated by an expert panel. Measurement performance was tested on 180 randomly selected Chinese MI patents. Thirty participants from the primary group completed the CM-MIDAS for test-retest reliability after 2 weeks. Reliability, validity and discriminatory power of the CM-MIDAS were calculated. RESULTS: Two items were modified as suggested by the expert panel. The overall CM-MIDAS had acceptable internal consistency with Cronbach's alpha coefficient 0.93 for the scale and 0.71-0.94 for the seven domains. Test-retest reliability by intraclass correlations was 0.85 for the overall scale and 0.74-0.94 for the seven domains. There was acceptable concurrent validity with significant (p < 0.05) correlations between the CM-MDAS and the Chinese Version of the Short Form 36. The principal components analysis extracted seven factors that explained 67.18% of the variance with high factor loading indicating good construct validity. CONCLUSION: Empirical data support CM-MIDAS as a valid and reliable disease-specific quality of life measure for Chinese Mandarin speaking patients with myocardial infarction.

Adult↗
PubMed2006

Purification of soluble CD14 fusion proteins and use in an electrochemiluminescent assay for lipopolysaccharide binding.

CD14, a 55kDa lipopolysaccharide binding glycoprotein, is a key element in both LPS-mediated activation of cells and endotoxin detoxification. A gene fragment containing residues 1-348 of the human LPS receptor CD14, representing the extracellular form of the molecule, was fused to the CH(2)-CH(3) portion of the human IgG heavy chain or to a 6x His tag and transfected into CHO cells. Stable cell lines of each were grown to produce recombinant protein in unsupplemented serum free media and CD14His was purified by ion-exchange chromatography. After passive immobilization onto a carbon surface both forms of the CD14 fusion proteins bound LPS-biotin in a dose-dependent manner in an electrochemiluminescent assay. Binding was inhibited by the anti-CD14 antibody S39 as well as by unlabeled LPS. This report describes an efficient method of purifying CD14 and a novel assay to detect bioactive lipopolysaccharide.

Animals↗
PubMed2006

Pulmonary toxicity associated with sirolimus treatment in kidney transplantation.

INTRODUCTION: An important side effect of sirolimus, a drug often used in organ transplantation, is pulmonary toxicity. MATERIALS AND METHODS: We present five kidney transplant patients who developed this toxicity associated with sirolimus. All underwent chest radiography computed tomography, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL), microbiological studies of the bronchial aspirate, blood, and sputum, and cytomegalovirus (CMV) polymerase chain reaction (PCR) in blood as well as two had transbronchial biopsies. RESULTS: All five were men of mean age 54.8 +/- 10.3 years. In two sirolimus formed part of de novo therapy, and three were converted from calcineurin inhibitors. The mean treatment time was 16.6 +/- 13.7 months, with trough levels of 11.3 +/- 3 ng/mL. The patients presented with fever, cough, dyspnea, anemia, and dyslipidemia. The radiological pattern was diffuse alveolointerstitial (n = 2), or bilateral basal interstitial (n = 2), or bilateral basal alveolar (n = 1). The cell count in the BAL was 95% to 99% macrophages. In two patients cultures for bacteria were positive: Hemophilus and Pseudomonas. Tests for fungi, mycobacteria, pneumocystis, and legionella, as well as PCR for CMV were all negative. Transbronchial biopsy yielded insufficient material in one patient and a deposit of fibrinoid material and nonnecrotizing granuloma in the other. Antibacterial therapy was started, three with cotrimoxazole and two with ganciclovir, with no response. The respiratory symptoms improved after withdrawal of sirolimus (mean, 2.4 +/- 1.5 days). The mean hospital stay was 19.8 +/- 14.1 days. CONCLUSION: Pulmonary toxicity due to sirolimus should be included in the differential diagnosis of kidney transplant patients who display signs of interstitial pneumonia. Its diagnosis is difficult requiring exclusion of other pulmonary diseases. Resolution of the symptoms was quick after suspension of the drug.

Adult↗
PubMed2006

Anterior uveitis associated with treatment with intravenous cidofovir in kidney transplant patients with BK virus nephropathy.

BACKGROUND: Polyomavirus-associated nephropathy (PVAN) is an important cause of kidney dysfunction and graft loss. Different treatment regimens have been used, including low-dose intravenous cidofovir. Anterior uveitis, a complication of this treatment, has been reported after its use in patients with cytomegalovirus-associated retinitis. We analyzed the incidence and associated risk factors for this disorder in patients with PVAN. PATIENTS AND METHODS: The study included 14 kidney-transplant patients who had received low doses of cidofovir after being diagnosed with PVAN. RESULTS: Five (35%) patients developed an episode of anterior uveitis. The mean number of cidofovir doses given was 6.8 +/- 1.6 as compared with 9.1 +/- 2.1 in patients who did not develop the disease. Creatinine clearance at diagnosis of the nephropathy and after terminating treatment was lower in the uveitis patients, who had a graft survival of 40% versus 100% in the patients who did not develop eye involvement. Treatment was suspended in the affected patients, with complete resolution in 80% after the administration of topical corticoids and cycloplegics. CONCLUSIONS: Anterior uveitis secondary to low-dose treatment with cidofovir is a common complication in patients with PVAN and is associated with the degree of renal involvement. In the absence of larger studies, cidofovir should be used with caution in patients with creatinine clearance below 30 mL/min.

Adult↗
PubMed2005

Mammalian lactoferrin receptors: structure and function.

Mammalian lactoferrin (Lf) receptors are suggested to have pivotal roles for mediating multiple functions of Lf. In this review, we focus on current knowledge of the structure and function of mammalian Lf receptors, mainly the first cloned Lf receptor that has been shown to be expressed in the infant small intestine at high levels but also in virtually all other tissues. The small intestinal Lf receptor takes up iron from Lf into cells and presumably exerts other physiological functions. Other Lf receptors in various tissues have also been reported to mediate some functions of Lf, such as modulating immune function, inhibiting platelet aggregation and enhancing collagen gel contractile strength. The detailed mechanisms behind the receptor-Lf interactions still need to be elucidated.

Animals↗
PubMed2005

The Healthgrid White Paper.

Over the last four years, a community of researchers working on Grid and High Performance Computing technologies started discussing the barriers and opportunities that grid technologies must face and exploit for the development of health-related applications. This interest lead to the first Healthgrid conference, held in Lyon, France, on January 16th-17th, 2003, with the focus of creating increased awareness about the possibilities and advantages linked to the deployment of grid technologies in health, ultimately targeting the creation of a European/international grid infrastructure for health. The topics of this conference converged with the position of the eHealth division of the European Commission, whose mandate from the Lisbon Meeting was "To develop an intelligent environment that enables ubiquitous management of citizens' health status, and to assist health professionals in coping with some major challenges, risk management and the integration into clinical practice of advances in health knowledge." In this context "Health" involves not only clinical procedures but covers the whole range of information from molecular level (genetic and proteomic information) over cells and tissues, to the individual and finally the population level (social healthcare). Grid technology offers the opportunity to create a common working backbone for all different members of this large "health family" and will hopefully lead to an increased awareness and interoperability among disciplines. The first HealthGrid conference led to the creation of the Healthgrid association, a non-profit research association legally incorporated in France but formed from the broad community of European researchers and institutions sharing expertise in health grids. After the second Healthgrid conference, held in Clermont-Ferrand on January 29th-30th, 2004, the need for a "white paper" on the current status and prospective of health grids was raised. Over fifty experts from different areas of grid technologies, eHealth applications and the medical world were invited to contribute to the preparation of this document.

Computer Communication Networks↗
PubMed2004

Privatisation of veterinary services in Jamaica: a case study.

Clinical veterinary services were privatised in Jamaica in September 1992. Using the limited official data, the authors briefly examine the premise and logistics behind transferring the responsibility for clinical services, which may be regarded as 'a private good', to private veterinary practitioners. There are indications that this privatisation model can work for farmers, despite financial problems in the livestock industry and a decline in production, caused by trade liberalisation policies and the substitution of cheaper imports. In addition, other national fiscal problems, such as a downturn in the economy, have left veterinarians attempting to boost production in a livestock industry which lacks adequate financial structuring and resources. The authors express concern that various unpublished projections since the last official agricultural survey in 1996 indicate that the livestock industry in Jamaica is diminishing. It is possible that valuable genetic breeding stock may never recover. A comprehensive study of the future of the livestock industry and its associated services is strongly urged. Ten years after the event, the authors reflect on the privatisation of clinical veterinary services in Jamaica and offer some suggestions to improve on the quality of the services offered by private veterinary practitioners.

Animal Husbandry↗
PubMed2001

Inhibition of gastrointestinal lipolysis by Orlistat during digestion of test meals in healthy volunteers.

The inhibition of digestive lipases by the antiobesity drug Orlistat along with lipolysis levels and fecal fat excretion were measured in healthy humans. Orlistat was found to be a powerful gastric lipase inhibitor, achieving 46.6--91.4% enzyme inhibition and thus greatly reducing gastric lipolysis of solid and liquid meals (11--33% of respective controls). Gastric lipase inhibition by Orlistat was extremely fast (half-inhibition time < 1 min). Duodenal lipolysis was reduced significantly by Orlistat given with the solid meal (32.6--37.6% of controls) but was only slightly reduced by Orlistat given with the liquid meal (74.5--100% of controls). Human pancreatic lipase (HPL) inhibition was found to be high (51.2--82.6%), however, regardless of the meal. These paradoxical results were explained when in vitro lipolysis experiments were performed. The rates of HPL inhibition by Orlistat were found to be similar with both types of meals (half-inhibition time 5--6 min), but the preemulsified triglycerides of the liquid meal were rapidly hydrolyzed by HPL before the enzyme was significantly inhibited by Orlistat. With the solid meal, the rate of hydrolysis of the meal triglycerides by HPL was slower than the rate of HPL inhibition by Orlistat. As predicted from the previous results, the effects of Orlistat on fat excretion levels were found to be much greater with the solid (40.5--57.4% of ingested fat) than with the liquid (4.2--18.8%) test meal.

Adult↗
PubMed2000

Risk factors in highway traffic accidents: a case control study.

The objective of this study was to identify risk factors related to the driver, the vehicle and the environment, that are associated with motor vehicles accidents on highways. A case and control design was used where the case was: the driver of a motor vehicle who was involved in an accident while traveling on the Mexico-Cuernavaca highway; and the control was: the driver or a motor vehicle who, traveling on the highway, completed the trip without being involved in a traffic accident. Risk factors associated with the occurrence of a traffic accident (P > 0.05) were: age under 25 years, frequent travel, traveling to work, alcohol consumption, driving during the daylight, on a week-day, under adverse weather conditions and in the Mexico Cuernavaca direction of road. Risks adjusted by logistic regression were: age under 25 years odds ratio (OR) 3.01, confidence interval (CI) (95%) 1.46-6.18; work as a travel reason OR 1.74, CI 1.06 2.86; alcohol intake OR 4.70, Cl 1.62 13.6; driving under adverse weather conditions OR 5.70, CI 3.66-8.85; traveling on a week-day OR 1.84, CI 1.14-2.94; during daylight hours OR 4.23, CI 2.36-7.58 and in the Mexico Cuernavaca direction of road OR 2.69, CI 1.67 4.32. The identification of factors associated with the risk of being involved in a highway traffic accident allows us to propose primary prevention measures for this important public health problem.

Accidents, Traffic↗
PubMed2000

The specific activities of human digestive lipases measured from the in vivo and in vitro lipolysis of test meals.

BACKGROUND & AIMS: The lipolytic potential of digestive lipases in vivo has always been deduced so far from their in vitro activities under nonphysiologic conditions. In the present study, the specific activities of human gastric lipase (HGL) and pancreatic lipase (HPL) were measured on dietary triglycerides (TGs) during test meal lipolysis. METHODS: Healthy human volunteers ingested a liquid or solid meal. The specific activities of HGL and HPL were estimated from the lipase and free fatty acid (FFA) outputs at the postpyloric and duodenal levels, respectively. Based on the in vivo data, lipolysis was also performed in vitro by mixing the meal either with gastric juice and subsequently with pancreatic juice and bile or with purified HGL and HPL. FFAs were measured by thin-layer chromatography, and the specific activities of HGL and HPL were expressed as micromoles of FFA per minute per milligram of lipase. RESULTS: In vitro, the specific activities on the liquid meal TGs were 32 (gastric juice) and 34 (pure lipase) micromol x min(-1) x mg(-1) with HGL and 47 (pancreatic juice) and 43 (pure lipase) micromol x min(-1). mg(-1) with HPL. The specific activities on the solid meal TGs were 33 (gastric juice) and 32 (pure lipase) micromol x min(-1) x mg(-1) with HGL and 12 (pancreatic juice) and 15 (pure lipase) micromol x min(-1) x mg(-1) with HPL. The in vivo values obtained were in the same range. The secretory lipase outputs were 21.6+/-14.5 mg HGL and 253.5+/-95.5 mg HPL with the liquid test meal and 15.2+/-5.1 mg HGL and 202.9+/-96.1 mg HPL with the solid test meal. CONCLUSIONS: The specific activities of HGL and HPL on meal TGs were much lower than those measured in vitro under optimized assay conditions (1300-8000). However, these low specific activities are enough for the meal TGs to be completely lipolysed, given the amounts of HGL and HPL secreted during a meal.

Adult↗
PubMed2000

Diagnosis of human immunodeficiency virus infection using an immunoglobulin E-based assay.

Immunoglobulin assays that are sensitive and specific for detecting human immunodeficiency virus type 1 (HIV-1) infection are especially important in developing countries where PCR and viral culture may not be readily available. Immunoglobulin E (IgE), which is elevated in HIV-1 infection, is the only antibody that does not cross the placenta, making it potentially valuable for viral detection in both children and adults. This study developed an assay for detection of HIV specific IgE antibodies in adults. A total of 170 serum samples from 170 adults (116 HIV positive and 54 HIV negative) were analyzed. Serum or plasma samples were treated by using the protein G affinity method. The HIV status was determined by using two IgG enzyme-linked immunosorbent assays (ELISAs) and one Western blot evaluation. The IgE enzyme immunoassay test for HIV-1 correctly identified the HIV status in 98.8% of the samples (168 of 170). One false-positive and one false-negative test occurred with the IgE ELISA, as well as with the IgG ELISA test but were correctly identified by the IgE test. Analysis of the data demonstrated a high specificity (99%) and sensitivity (99%) of the IgE test, with 95% confidence intervals. The IgE assay appears to be sensitive and specific, suggesting that IgE-specific antibodies offer an effective method to detect HIV-1 infection in adults.

Adult↗
PubMed1999

Human pancreatic lipase: colipase dependence and interfacial binding of lid domain mutants.

Five key amino acid residues from human pancreatic lipase (HPL) are mutated in some pancreatic lipase-related proteins 2 (PLRP2) that are not reactivated by colipase in the presence of bile salts. One of these residues (Y403) is involved in a direct interaction between the HPL C-terminal domain and colipase. The other four residues (R256, D257, Y267, and K268) are involved in the interactions stabilizing the open conformation of the lid domain, which also interacts with colipase. Here we produced and characterized three HPL mutants: HPL Y403N, an HPL four-site mutant (R256G, D257G, Y267F, and K268E), and an HPL five-site mutant (R256G, D257G, Y267F, K268E, and Y403N), in which the HPL amino acids were replaced by those present in human PLRP2. Colipase reactivated both the HPL Y403N mutant and HPL, and Y403 is therefore not essential for lipase-colipase interactions. Both the HPL four-site and five-site mutants showed low activity on trioctanoin, were inhibited by bile salts (sodium taurodeoxycholate, NaTDC) and were not reactivated by colipase. The interfacial binding of the HPL four-site mutant to a trioctanoin emulsion was suppressed in the presence of 4 mM NaTDC and was not restored by addition of colipase. Protein blotting/protein overlay immunoassay revealed that the HPL four-site mutant-colipase interactions are not abolished, and therefore, the absence of reactivation of the HPL four-site mutant is probably due to a lid domain conformation that prevents the interfacial binding of the lipase-colipase complex. The effects of colipase were also studied with HPL(-lid), an HPL mutant showing an 18-residue deletion within the lid domain, which therefore has only one colipase interaction site. HPL(-lid) showed a low activity on trioctanoin, was inhibited by bile salts, and recovered its lipase activity in the presence of colipase. Reactivation of HPL(-lid) by colipase was associated with a strong interfacial binding of the mutant to a trioctanoin emulsion. The lid domain is therefore not essential for either the interfacial binding of HPL or the lipase-colipase interactions.

Adsorption↗
PubMed1998

Differential colocalization of estrogen receptor beta (ERbeta) with oxytocin and vasopressin in the paraventricular and supraoptic nuclei of the female rat brain: an immunocytochemical study.

Evidence exists for the localization of the newly identified estrogen receptor beta (ERbeta) within the rat paraventricular nucleus (PVN) and supraoptic nucleus (SON), regions which lack ERalpha. Presently, we investigate whether ERbeta-like-immunoreactivity (-ir) is found within cells of several major neuropeptide systems of these regions. Young adult Sprague-Dawley rats were ovariectomized (OVX), and 1 week later half of the animals received estradiol-17beta (E). Dual-label immunocytochemistry was performed on adjacent sections by using an ERbeta antibody, followed by an antibody to either oxytocin (OT), arginine-vasopressin (AVP), or corticotropin releasing hormone. Nuclear ERbeta-ir was identified within SON and retrochiasmatic SON, and in specific PVN subnuclei: medial parvicellular part, ventral and dorsal zones, dorsal and lateral parvicellular parts, and in the posterior magnocellular part, medial and lateral zones. However, the ERbeta-ir within magnocellular areas was noticeably less intense. OT-/ERbeta-ir colocalization was confirmed in neurons of the parvicellular subnuclei, in both OVX and OVX+E brains ( approximately 50% of OT and 25% of ERbeta-labeled cells between bregma -1.78 and -2.00). In contrast, few PVN parvicellular neurons contained both AVP- and ERbeta-ir. As well, very little overlap was observed in the distribution of cells containing corticotropin releasing hormone- or ERbeta-ir. In the SON, most nuclear ERbeta-ir colocalized with AVP-ir, whereas few OT-/ERbeta-ir dual-labeled cells were observed. These findings suggest that estrogen can directly modulate specific OT and AVP systems through an ERbeta-mediated mechanism, in a tissue-specific manner.

Animals↗
PubMed1997

Postnatal development of the exocrine pancreas in suckling goat kids.

A total of 25 preruminant Granadina breed goats were used. They were bottle-fed goat milk ad libitum from postnatal day 3 to 28. Until the age of 3 d, kids were fed colostrum. Body weight, pancreas weight, total protein concentration, enzyme activities in pancreatic tissue and hormone concentrations (cortisol, gastrin, T3 and T4) were determined at 3, 7, 14, 21 and 28 d of age. Our results show that the rates of pancreatic synthesis and secretion of chymotrypsin are well developed at birth in the kid, and may compensate for possible deficiencies in gastric and/or enterocytes intracellular proteolysis. In week 4, there was a marked increase in amylase activity, change that can be attributed to the beginning of the transitional period known as weaning. The significant increase in circulating concentration of cortisol during week 4 suggests the involvement of corticosteroid as a mediator of pancreatic development at weaning. Changes in blood levels of this hormone are believed to be important in the expression of amylase in the neonatal period. However, T3-T4 blood levels remained unchanged from d 3 to 28, suggesting that, in the kid, these hormones appear to have no clear influence upon the postnatal development of the exocrine pancreas.

Animals↗
PubMed1996

Calcitriol differentially modulates mRNA encoding calcitriol receptors and calcium-binding protein 9 kDa in human fetal jejunum.

Human intestinal mucosa consists of highly active epithelial cells in continual renewal and differentiation processes anatomically located at different portions of the villi. Besides its well recognized role in bone cell homeostasis, calcitriol has been attributed a role in cellular differentiation and proliferation in normal and cancerous cells. In this report, we show that in human fetal jejunum, depending upon the stage of gestation, calcitriol either enhances or decreases the levels of mRNA coding for its receptor. However, it up-regulates at all times those coding for the Vitamin D-dependent Calcium Binding Protein 9kDa. The present observations open interesting possibilities as to the role of calcitriol in the in utero human gut development and the control of colorectal cancers.

Base Sequence↗