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Biomedical subjects

D Ruiz

Publications and source records attributed to D Ruiz.

At least 19 recordsLinked to original sources
PubMed2006

Kinetics of antibodies in sera, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infections.

OBJECTIVES: The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue infection were studied. DESIGN: Serum, saliva, and urine samples were collected from 22 patients with clinical and confirmed dengue 3 virus infection during the outbreak in Havana City in 2001. They were tested by capture IgM (MAC-ELISA), IgA (AAC-ELISA), and IgE (EAC-ELISA) and IgG ELISA inhibition method (EIM) to detect specific dengue antibodies. RESULTS: Similar kinetics were observed in IgM, IgA, and IgG antibodies in saliva and IgA and IgG in urine samples from secondary cases compared with kinetics in serum samples, although the values were lower. No IgG antibody was detected in saliva and urine samples in primary cases and IgM antibody was not detected in urine samples from either primary or secondary infection. All secondary cases were positive for IgG in saliva and urine samples at day 7. The kinetics of specific IgE antibodies in primary and secondary cases were different. CONCLUSIONS: The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infection were studied for the first time, showing its behavior and usefulness in dengue virus diagnosis. The specific IgE could play a role as a serological marker in secondary infections.

Adult↗
PubMed2005

Prevention of hyperacute rejection in a model of orthotopic liver xenotransplantation from pig to baboon using polytransgenic pig livers (CD55, CD59, and H-transferase).

INTRODUCTION: The search for alternative sources for transplant organs leads us to the search for animals as an inexhaustible source of organs. The objective of this study was to analyze whether livers from polytransgenic pigs expressing the human complement regulatory proteins CD55 (hDAF), CD59, and alfa alpha1,2-fucosyltransferase (H-transferase), protected against hyperacute rejection after orthotopic liver xenotransplantation to a baboon and also to study pig liver function in a nonhuman primate. MATERIALS AND METHODS: Nine liver transplants from pig to baboon were divided into two groups: a control group (n = 4) of genetically unmodified pigs and an experimental group (n = 5) of pigs transgenic for CD55, CD59, and H-transferase as donors. All the donating piglets obtained through hysterectomy were maintained in specific pathogen-free conditions. The selection of transgenic pig donors followed demonstration of transgene expression using monoclonal antibodies (antiCD55, antiCD59) and immunohistological studies on liver biopsies. RESULTS: All animals in the control group developed hyperacute rejection with survival rates less than 16 hours without function of transplanted livers. In the experimental group none of the animals suffered hyperacute rejection. Survival in this group was between 13 and 24 hours. The livers were functional, producing bile and maintaining above 35% prothrombin activity. Only in one case was there primary dysfunction of the xenograft. CONCLUSION: Polytransgenic livers for complement regulatory proteins prevent hyperacute rejection when xenotransplanted into a baboon.

Acute Disease↗
PubMed2004

Serological markers during dengue 3 primary and secondary infections.

BACKGROUND: The detection of the IgM antibody for the dengue virus in serum by ELISA has become one of the most important and useful methods for diagnosis of dengue using a single acute-phase serum sample. Currently, this system is an invaluable tool for the surveillance of dengue fever (DF) and dengue hemorrhagic fever (DHF). The usefulness of other serological markers such as IgA and IgE have been less studied. OBJECTIVE: To study the IgM, IgA and IgE specific antibody response in dengue 3 infected patients with different clinical picture and type of infection. STUDY DESIGN: One hundred and twenty-seven serum samples collected on days 5-7 at the onset of fever from clinically and serologically confirmed dengue cases were studied. Forty-two were classified as primary dengue fever cases, 48 as secondary dengue fever cases and 37 as secondary dengue hemorrhagic fever cases. All samples were tested by capture ELISA in order to detect dengue IgM, IgA and IgE antibodies. RESULTS AND CONCLUSIONS: In this study, significant differences were observed in the IgM, IgA and IgE response between the study groups. High IgA and IgE OD ratios in secondary dengue cases were found. The usefulness of serotype specific IgM antibody detection is also analyzed and discussed. A priority for future dengue research in terms of protection, recovery of infection and immunopathogenesis is to elucidate the role of these immunoglobulins. The cross reactivity response to IgM between dengue virus serotypes in primary and secondary cases should also be more studied.

Antibodies, Viral↗
PubMed2001

Favourable effect of the combination of acute and chronic graft-versus-host disease on the outcome of allogeneic peripheral blood stem cell transplantation for advanced haematological malignancies.

To assess the influence of graft-versus-host disease (GVHD) on the outcome of patients with advanced haematological malignancies (AHM) who received a primary, unmodified allogeneic peripheral blood progenitor cells transplant (allo-PBT) from a human leucocyte antigen (HLA) identical sibling donor, we analysed 136 patients with myeloid neoplasms (n = 70) or lymphoproliferative disorders (n = 66), transplanted at 19 Spanish institutions. Median age was 35 years (range 1-61). The cumulative incidence of relapse for all patients was 34% (95% CI, 26-42%), 41% (95% CI, 33-49) for patients without GVHD and 14% (95% CI, 3-25) (P = 0.001) for patients with acute and chronic GVHD. After a median follow-up of 11 months (range 2-49), 60 (44%) patients remained alive with an actuarial probability of overall survival and disease-free survival (DFS) at 30 months of 31% (95% CI, 21-41%) and 28% (95% CI, 17-39%) respectively. In patients surviving > 100 d, the low incidence of relapse in those with acute and chronic GVHD led to a DFS of 57% (95% CI, 38-76%) compared with a DFS of 34% (95% CI, 17-51%) in the remaining patients (P = 0.03). Our results indicate a reduced incidence of relapse for patients with AHM receiving an unmodified allo-PBT and developing acute and chronic GVHD, which results in an improved DFS.

Acute Disease↗
PubMed2001

Coupling between annual and ENSO timescales in the malaria-climate association in Colombia.

We present evidence that the El Niño phenomenon intensifies the annual cycle of malaria cases for Plasmodium vivax and Plasmodium falciparum in endemic areas of Colombia as a consequence of concomitant anomalies in the normal annual cycle of temperature and precipitation. We used simultaneous analyses of both variables at both timescales, as well as correlation and power spectral analyses of detailed spatial (municipal) and temporal (monthly) records. During "normal years," endemic malaria in rural Colombia exhibits a clear-cut "normal" annual cycle, which is tightly associated with prevalent climatic conditions, mainly mean temperature, precipitation, dew point, and river discharges. During historical El Niño events (interannual time scale), the timing of malaria outbreaks does not change from the annual cycle, but the number of cases intensifies. Such anomalies are associated with a consistent pattern of hydrological and climatic anomalies: increase in mean temperature, decrease in precipitation, increase in dew point, and decrease in river discharges, all of which favor malaria transmission. Such coupling explains why the effect appears stronger and more persistent during the second half of El Niño's year (0), and during the first half of the year (+1). We illustrate this finding with data for diverse localities in Buenaventura (on the Pacific coast) and Caucasia (along the Cauca river floodplain), but conclusions have been found valid for multiple localities throughout endemic regions of Colombia. The identified coupling between annual and interannual timescales in the climate-malaria system shed new light toward understanding the exact linkages between environmental, entomological, and epidemiological factors conductive to malaria outbreaks, and also imposes the coupling of those timescales in public health intervention programs.

Animals↗
PubMed2001

Results of the management of upper gastrointestinal bleeding from gastroesophageal varices.

INTRODUCTION: The management of upper gastrointestinal bleeding caused by rupture of gastric and/or esophageal varices in patients with liver cirrhosis must focus on the initial control of the haemorrhage avoiding further worsening of an already poor liver function and the prevention of early relapsing bleeding. Therapeutic options include endoscopic, pharmacological and surgical methods. MATERIAL AND METHODS: Prospective study of the results obtained after the follow-up of 90 bleeding episodes in a total of 54 patients, 35 men and 19 women, with a mean age of 58 years (range 32-77), to which a therapeutic protocol for acute bleeding secondary to portal hypertension was applied over a 22-months period. Patient classification according to Child-Pugh upon admission was 57% Child A, 34% Child B and 9% Child C. RESULTS: Mean hospital length of stay was 9 days (2-50). Of the 90 bleeding episodes, 15 were early relapsing bleeding episodes (16.7%). Twelve patients died (mortality rate of 22.2% by patients and 13.4% by bleeding episodes). Twelve emergency surgical procedures were performed because of the persistence of haemorrhage. Forty one per cent of patients were readmitted because of relapsing bleeding at least once during the follow-up period. CONCLUSIONS: Management of upper gastrointestinal bleeding due to gastroesophageal varices in patients with liver cirrhosis requires a combined therapy in order to attain maximum effectiveness in acute haemorrhagic episodes and to address all potential later consequences. Such therapy should be provided in a hospital fully equipped and with specialists in this pathology. Based on our experience, emergency surgery as rescue treatment for persistent or short-term relapsing bleeding should be restricted to patients with good hepatic function because of its high morbidity and mortality.

Adult↗
PubMed1999

Role of Hydrophobic Effect on the Noncovalent Interactions Between Salicylic Acid and a Series of beta-Cyclodextrins.

The molecular complexation of salicylic acid (o-hydroxybenzoic acid) by beta-cyclodextrin (beta-CD) and/or two of its most used derivatives, 2,6-di-O-methyl-beta-cyclodextrin (DIMEB) and hydroxypropyl-beta-cyclodextrin (HPBCD), was studied from pH potentiometric measurements. The role of the hydrophobic effect was evaluated by studying the influence of the presence of different constant amounts of a series of alcohols (methanol, ethanol, propanol, and butanol) on the CD:guest interaction at 25 degrees C. The study was carried out by measuring the pH of the hydroalcoholic solutions of the guest, whose concentration is kept constant, as a function of cyclodextrin concentration. The dissociation constant of salicylic acid and the binding constants of the inclusion complexes formed by the CD and both the nonionized (HSA) and ionized (SA-) forms of the guest were simultaneously determined at all alcohol concentrations by using a model previously derived by us. The carboxylic forms were found to bind the CD with higher affinities than the carboxylate partners, irrespective of the polarity of the medium and the cyclodextrin used. The ratio KCD:HSA/KCD:SA- is a constant value characteristic of the cyclodextrin, which points to the hydrophobic effect as one of the main forces involved in the association. A clear influence of the solvent polarity on the affinity of binding was found, in the sense that, as long as the medium becomes more apolar, the interaction between the drug and the cyclodextrin is weakened. A phenomenological limit association curve is proposed to define the limiting conditions for association in the presence of an alcohol as a cosolvent. Copyright 1999 Academic Press.

Journal Article↗
PubMed1998

[Is surgery for portal hypertension a contraindication for liver transplantation?].

INTRODUCTION: Orthotopic liver transplantation (OLT) is the only curative treatment for hepatic cirrhosis and is the most effective in the control of portal hypertension. The aim of this study was to analyze whether greater morbi-mortality is observed in patients undergoing liver transplantation with previous surgery for portal hypertension with respect to patients not having undergone this surgery. MATERIALS AND METHODS: Different variables were analyzed in 2 groups of transplanted patients: one of 18 patients who had previously undergone surgery for portal hypertension and another group of 54 patients without this previous surgery. RESULTS: The following factors were studied: mean operative time and length of anahepatic phase, intraoperative consumption of concentrates of erythrocytes, fresh frozen plasma, units of platelets and cryoprecipitates, days of mechanical ventilation, stay in the ICU and total postoperative stay. No significant differences were observed (p < 0.05) in any of these factors or in survival. DISCUSSION: On analysis of the difficulty of surgical technique, postoperative evolution and survival and based on the variables described it may be concluded that previous surgery for portal hypertension does not only not contraindicate posterior liver transplantation, but rather may be useful in patients with an adequate hepative reserve presenting variceal hemorrhage since posterior transplantation does not present a worsened prognosis.

Adult↗
PubMed1997

Citrus response to salinity: growth and nutrient uptake.

To determine the effects of salinity on relative growth rate (RGR), net assimilation rate on a leaf weight basis (NAR(w)), leaf weight ratio (LWR), and nutrient uptake and utilization of citrus, we grew four citrus rootstocks (sour orange, Cleopatra mandarin, Carrizo citrange and Citrus macrophylla) in nutrient solutions containing 0, 10, 20, 40 or 80 mM NaCl for 20, 40 or 60 days. For each element analyzed, specific absorption rate (SAR) and specific utilization rate on a leaf basis (SUR(L)) were calculated for the period between Days 40 and 60. Relative growth rate decreased with time for all treatments and rootstocks. Salt treatment significantly reduced both RGR and NAR(w), whereas LWR showed no definite trend. In all rootstocks, NAR(w), but not LWR, was significantly correlated with RGR, indicating that NAR(w) was an important factor underlying the salinity-induced differences in RGR among the citrus rootstocks. At Day 60, salinity had a significant effect on leaf concentrations of Cl, Na, K, Ca, Mg, P, Fe, Mn and Zn and on the SAR and SUR(L) of most elements. In general, RGR was correlated with SAR and SUR(L). Therefore, in addition to osmotic effects and the inhibitory effects of high concentrations of Cl(-) and Na(+), an imbalance of essential nutrients may also contribute to the reduction in plant growth under saline conditions.

Journal Article↗
PubMed1994

[Alcohol consumption by primary care physicians].

OBJECTIVE: To find the consumption of alcoholic drinks by Primary Care doctors. DESIGN: A descriptive study using an anonymous questionnaire. SETTING: Health base areas located in the Baix Llobregat and in Barcelona city. MEASUREMENTS AND MAIN RESULTS: Total coverage was 68.7%. In the group which replied, daily consumption along with week-end consumption predominated. Men consumed alcohol more often and in greater quantity than women. The prevalence of excessive drinkers according to the PAPPS criteria was 5.9%. 29% of the doctors exceeded the level of alcohol consumption considered acceptable by their own criteria, no gender differences being appreciated. Similarly, 33% of them accepted consumption above that recommended by the experts. CONCLUSIONS: The consumption of alcoholic drinks found among Primary Care doctors was low in comparison with other studies of medical groups or the general population. The Primary Care doctor occupies a privileged position in the prevention of excessive consumption of alcoholic drinks, which implies that their own alcohol consumption and training could have an impact on carrying out preventive activities in this field.

Adult↗
PubMed1992

Annular submitral left ventricular aneurysm.

Annular subvalvular aneurysms have been reported rarely in Caucasian individuals. We describe the case of a white man who had an asymptomatic annular submitral left ventricular aneurysm diagnosed during the diagnostic work-up of cervical lymphadenopathies. Our case is unique because of its occurrence in a Caucasian and its characteristic radiological features.

Adult↗
PubMed1991

Molecular analysis of the dmpM gene encoding an O-demethyl puromycin O-methyltransferase from Streptomyces alboniger.

The nucleotide (nt) sequence of a 1332-bp fragment of Streptomyces alboniger DNA containing the gene (dmpM), which encodes an O-demethyl puromycin O-methyltransferase (DMPM), has been determined. The dmpM gene contains a 1131-nt open reading frame which encodes a polypeptide of Mr 40,303; this is consistent with the 44 +/- 2.5- and 160-kDa sizes of the DMPM monomer and its native form, respectively. The ATG start codon of dmpM is 50 bp downstream from the coding sequence of the gene (pac), which determines a puromycin N-acetyltransferase. S1 mapping experiments indicate that pac and dmpM are transcribed on a single transcript, which ends at least 500 nt downstream from the dmpM stop codon. The deduced amino acid sequence of DMPM shows significant similarities to those of a hydroxyindole O-methyltransferase, which is involved in the biosynthesis of melatonin by bovine pineal glands [Ishida et al., J. Biol. Chem. 262 (1987) 2895-2899], a hydroxyneurosporene methyltransferase, which is involved in carotenoid biosynthesis in the purple nonsulfur bacterium, Rhodobacter capsulatus [Armstrong et al., Mol. Gen. Genet. 216 (1989) 254-268] and two O-methyltransferases of the tetracenomycin biosynthesis pathway from Streptomyces glaucescens.

Acetylserotonin O-Methyltransferase↗