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C Rodríguez

Publications and source records attributed to C Rodríguez.

At least 109 records · Page 6Linked to original sources
PubMed1998

Identification of ampullary and isthmic oviductal fluid proteins that associate with the bovine sperm membrane.

The objective of this study was to define the complement of ampullary and isthmic oviductal fluid proteins that associate with the sperm membrane during the non-luteal and luteal stages of the oestrous cycle. Oviductal fluid was obtained from three dairy cows via indwelling cannulae in the ampulla and isthmus of the same oviduct. Daily samples of oviductal fluid were combined by region and stage of the cycle to create pools consisting of non-luteal isthmic, luteal isthmic, non-luteal ampullary, and luteal ampullary oviductal fluid. An aliquot from each oviductal fluid pool was biotinylated by incubation in biotin reagent. Spermatozoa from three fertile bulls were pooled, washed and incubated for 4 h in each of the four pools of biotinylated oviductal fluid. After incubation, sperm membrane proteins were solubilized, and proteins subjected to one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blotting. The biotinylated oviductal fluid proteins that associated with the sperm membranes were detected by avidin-horseradish peroxidase and diaminobenzidine substrate. Eight oviductal fluid proteins with apparent molecular weights of 97, 75, 66, 55, 48, 34, 28 and 24 kDa were consistently detected to associate with the sperm membrane. Differences in ampullar and isthmic fluid proteins that associated with sperm during the luteal and non-luteal stage of the oestrous cycle were not detected.

Animals↗
PubMed1998

[Population reference values of the Spanish version of the Health Questionnaire SF-36].

BACKGROUND: Perceived health status measurements reference values an important information source for health services research. Population-based norms have been proposed to increase their interpretability. In this paper, we have obtained the norms of the Spanish version of the SF-36 Health Survey and have compared them with US norms the questionnaire. MATERIAL AND METHODS: Data were obtained in the home interview survey on drug consumption (February 1996). This is a cross-sectional study of a multi-stage, stratified random sample of non-institutionalized individuals 15 and older residents in Spain. The final sample included 9,984 individuals, but the analysis is based on those individuals 18 or older (n = 9,151). Personal home interviews were carried out. Information included: the SF-36, legal and illegal drugs consumption, and socio-demographic data, among others. Central trend and dispersion statistics were estimated for each of the SF-36 dimension scores according to gender and age group. Cronbach's alpha coefficients were calculated to estimate the reliability of scores. RESULTS: For most SF-36 dimensions, scores were higher (better) among men and among younger age groups (p < 0.01). There was a monotonic score gradient by age which was more intense for physical function and bodily pain. All Cronbach's alpha coefficients were higher than 0.7 (ranging from 0.78 to 0.96). Spanish norms were very similar to those obtained in the US. CONCLUSIONS: Results presented should be considered the population-based norms of the Spanish version of the SF-36 Health Survey and may be useful for interpreting the questionnaire scores. These norms, which are very similar to the original US questionnaire both in absolute values and in the gender and age group distribution patterns, should be carefully used. Considerations for use discussed in the paper should be taken into account.

Adolescent↗
PubMed1998

[Trends in human immunodeficiency virus infection prevalence in homosexual/bisexual men in Madrid (1986-1995)].

BACKGROUND: We analysed the trend in seroprevalence for human immunodeficiency virus (HIV) in homosexual or bisexual men who voluntary requested the test in a sexually transmitted disease/HIV clinic in Madrid. PATIENTS AND METHODS: We studied 5,424 homo/bisexual non-injecting drug user (non-IDU) men, who came for the first time since 1986 to 1995. We analysed the HIV seroprevalence taken into account the year, age and exchange of sex by money. A hundred and thirty-six IDU homo/bisexual men were also attended during the same period and they were compared with non-IDU. RESULTS: HIV seroprevalence among the 5,424 non-IDU homo/bisexual men were 20.2%, rising from 19.6% in 1986 to 29.6% in 1990. After then, the trend decreased to 15.3% in 1995 (chi 2 for trend, 66.8; p < 0.0001). Average age was three years higher among seropositives (p < 0.0001), and showed an upward trend from 29.9 in 1986 to 34.6 in 1995 (p = 0.0059). Seroprevalence among homosexuals younger than 25 fell in the last years. One percent of individuals had ever practiced the prostitution. They were younger (average age, 27.6), and their HIV seroprevalence were 25.9%. A hundred and thirty-six IDU homo/bisexual men were also attended for the first time, being 2.4% of overall homo/bisexual men. They had a higher seroprevalence (48.5%) than non-IDU (p < 0.0001), and did not show any significative time-trend. CONCLUSIONS: A favourable evolution can be observed in HIV seroprevalence among homo/bisexual from Madrid, Spain, men who came to be tested, especially among the youngest. Prevention programs should make an effort to maintain this trend.

Adult↗
PubMed1998

Left anterior descending coronary artery bypass grafting through minimal thoracotomy.

BACKGROUND: In recent years, minimally invasive direct coronary artery bypass grafting has emerged as a valid tool for revascularization in a select group of patients with severe lesions of the left anterior descending coronary artery. Here we report the clinical results using two devices designed by us to facilitate the harvesting of the left internal mammary artery up to its origin and to occlude and stabilize the left anterior descending coronary artery while placing the anastomosis. METHODS: From January 1996 to January 1998, 122 patients underwent minimally invasive direct coronary artery bypass grafting in the Department of Cardiac Surgery, Favaloro Foundation. One hundred twelve patients received a single left internal mammary artery-left anterior descending coronary artery bypass graft, and in 10 patients, an additional bypass graft was performed. RESULTS: Most patients were discharged on day 2 or 3 after the procedure. Three patients (2.5%) had a perioperative myocardial infarction. The overall hospital mortality rate was 3.3% (4 patients). CONCLUSIONS: The combination of team experience, more careful dissection of the left internal mammary artery up to its origin, and use of the stabilizer-occluder and interrupted suture technique for the anastomosis has markedly improved our results.

Adult↗
PubMed1998

Melatonin decreases mRNA for histone H4 in thymus of young rats.

The antiproliferative properties of melatonin have been previously demonstrated for several normal and tumoral tissues. In a recent report we have shown that melatonin is able to inhibit programmed cell death in thymus both, in vivo and in vitro. Given that other authors have related programmed cell death and cell proliferation and that no previous reports on melatonin and cell division exist on thymus, we decide to study the possible antiproliferative effect of melatonin in this organ measured as the levels of mRNA for the histone H4. We found that melatonin inhibits cell division on thymus when administered chronically both, at high (500 microg/body weight) and low (50 microg/body weight) dose. We also found a circadian rhythm of the mRNA for histone H4, opposed to the one previously described for melatonin, supporting the negative regulation by this hormone of cell division on thymus. A single dose of melatonin (50 microg/body weight) was not able to decrease the levels of mRNA for H4 in the time-points studied but after two hours of its administration. Finally, we report the inhibitory effect of melatonin in the cell proliferation of Harderian gland, brain, lung and kidney.

Animals↗
PubMed1998

T lymphocytes that infiltrate nasal polyps have a specialized phenotype and produce a mixed TH1/TH2 pattern of cytokines.

BACKGROUND: Nasal polyps (NPs) are inflammatory reactions in the nasal mucosa the etiology and pathogenesis of which remains unknown. OBJECTIVE: The purpose of this study was to study in detail the phenotype and function of T lymphocytes infiltrating NPs by analyzing the expression of surface markers and cytokine secretion. METHODS: NP tissue samples and peripheral blood were obtained from 18 patients. Mononuclear cells were purified from these samples, and their phenotype was investigated by triple-color immunofluorescence and flow cytometric analysis. Cytokine production was determined in cultures by using an ELISA technique. RESULTS: NP lymphoid cells mainly consisted of T lymphocytes. These T lymphocytes showed a CD45RO+CD45RA- phenotype and expressed pan-T cell molecules; the CD8+ subset was predominant. NP T cells showed a lower density of CD28, CD3, and TCR-alphabeta compared with T cells from peripheral blood. NP T lymphocytes expressed the activation markers DR and CD69 and exhibited the adhesion molecule profile CD54+, CD62L-, and CD103+ CD49dlow. Virtually all NP T cells bore CD95 (FAS), but they did not undergo apoptosis, either spontaneously or induced by CD95 cross-linking with the mAb CH11. The pattern of cytokines secreted by NP T lymphocytes was characterized by the spontaneous and simultaneous production of IFN-gamma and IL-5. Neither IL-2 nor IL-4 were detectable in nonstimulated cultures. CONCLUSION: This study defines the T lymphocytes that infiltrate NPs as memory T cells in an activated status, with homing properties related to the mucosal immune system. They are resistant to anti-CD95-mediated apoptosis and produced a mixed TH1 /TH2 cytokine pattern as defined by the simultaneous production of IFN-gamma and IL-5.

Adult↗
PubMed1998

Study of common aerobic flora of human cerumen.

Cerumen is the product of the secretion of the sebaceous, ceruminous or apocrine glands together with cells exfoliated from the cornified stratum of the epithelium of the external auditory canal (EAC). In the present study we identified and quantified common flora of human cerumen. The mean count obtained was 10(6) microorganisms per ml of cerumen suspension. In 24 pools of cerumen (33.3 per cent) the isolates were monomicrobial, Staphylococcus epidermidis (12), Corynebacterium spp (10), Staphylococcus aureus (1) and Streptococcus saprophyticum (1). In 48 pools (66.6 per cent) we found polymicrobial isolates. The most commonly isolated bacteria in these polymicrobial isolates were S. epidermidis (35) and Corynebacterium spp. (43). It is noteworthy that there were isolates of Candida albicans in three cases; in one case of Pseudomonas stutzeri, in one case of Pseudomonas aeruginosa, and, on seven occasions, of S. aureus. The organisms isolated as common bacterial components of human cerumen in our experience were similar to those found by other authors. However, the mean count was much higher. This could be related to climatic conditions and to the length of time the cerumen had remained in the external auditory canal.

Adolescent↗
PubMed1998

Pharmacokinetics of indomethacin in sheep after intravenous and intramuscular administration.

The pharmacokinetics of indomethacin (1 mg/kg) was determined in six adult sheep after intravenous (i.v.) and intramuscular (i.m.) injection. Plasma concentrations were maintained within the therapeutic range (0.3-3.0 microg/mL) from 5 to 50 min after i.v. and from 5 to 60-90 min after i.m. administration. After two trials, indomethacin best fitted an open two-compartment model. The mean (+/- SD) volumes of distribution at steady state (Vd(ss)) were 4.10 +/- 1.40 and 4.21 +/- 1.93 L/kg and the mean clearance values (ClB) were 0.17 +/- 0.06 and 0.22 +/- 0.12 L/h x kg for i.v. and i.m. routes, respectively. The elimination phase half-lives did not show any significant difference between routes of injection (t1/2beta = 17.4 +/- 4.6 and 21.25 +/- 4.44 h, i.v. and i.m. respectively). After i.m. administration, plasma maximum concentration (Cmax = 1.10 +/- 0.68 microg/mL) was reached 10 min after dosing; the absorption phase was fast (Kab = 26 +/- 18 h(-1)) and short (t1/2ab = 2.33 +/- 1.51 min) and the mean bioavailability was 91.0 +/- 32.8%, although there was considerable interanimal variation. In some individuals, bioavailability was higher than 100%. This fact combined with the slower elimination phase after i.m. than after i.v. administration, could be related with enterohepatic recycling.

Animals↗
PubMed1998

Detection and typing of human papillomavirus DNA in benign and malignant tumours of laryngeal epithelium.

The role of human papillomaviruses (HPV) in laryngeal squamous cell carcinoma has not yet been established. Thirty-three cases of laryngeal squamous cell carcinoma were analysed for the presence of HPV DNA and compared with 25 cases of normal larynx and 29 cases of laryngeal squamous papilloma in their positivity index. The presence of HPV DNA was analysed by using L1 consensus primers and also by primers specific for the E7 gene of HPV types 16 and 18. Four normal laryngeal samples (16%) were positive for HPV DNA against the 24 samples (82%) (p < 0.001) found for laryngeal papilloma and 16 (48.5%) (p < 0.05) found for laryngeal squamous cell carcinoma. HPV 16 was the type most frequently found in laryngeal carcinoma samples. Our results support an etiologic role for this type of HPV in the pathogenesis of laryngeal carcinoma.

Adult↗
PubMed1998

Multiple recombination events maintain sequence identity among members of the nitrogenase multigene family in Rhizobium etli.

A distinctive characteristic of the Rhizobium genome is the frequent finding of reiterated sequences, which often constitute multigene families. Interestingly, these families usually maintain a high degree of nucleotide sequence identity. It is commonly assumed that apparent gene conversion between reiterated elements might lead to concerted variation among members of a multigene family. However, the operation of this mechanism has not yet been demonstrated in the Rhizobiaceae. In this work, we employed different genetic constructions to address the role of apparent gene conversion as a homogenizing mechanism between members of the plasmid-located nitrogenase multigene family in Rhizobium etli. Our results show that a 28-bp insertion into one of the nitrogenase reiterations can be corrected by multiple recombination events, including apparent gene conversion. The correction process was dependent on the presence of both a wild-type recA gene and wild-type copies of the nitrogenase reiterations. Frequencies of apparent gene conversion to the wild-type nitrogenase reiterations were the same when the insertion to be corrected was located either in cis or in trans, indicating that this event frequently occurs through intermolecular interactions. Interestingly, a high frequency of multiple crossovers was observed, suggesting that these large plasmid molecules are engaging repeatedly in recombination events, in a situation akin to phage recombination or recombination among small, high-copy number plasmids.

Base Sequence↗
PubMed1998

Effects of verapamil, sodium nitroprusside and calcium deprivation on the phenylephrine-induced contraction of smooth muscle strips from the reticular groove of adult cattle.

The effects of verapamil, sodium nitroprusside and calcium deprivation on the smooth muscle strips from the floor of the reticular groove of adult cattle were studied. The mechanical activity of the muscle strip was recorded isometrically. Contraction was induced with phenylephrine (10(-6) mol/l) in Tyrode solution. Verapamil (10(-6) mol/l) produced a high inhibition of the response, phasic and tonic (P < 0.05). Sodium nitroprusside (10(-6) mol/l) reduced mainly the phasic contraction (P < 0.05). Deprivation of Ca2+ from extracellular medium produced a high inhibition of the tonic phase. This study indicates that the action of verapamil on the reticular groove smooth muscle may be partially related to blockade of calcium entry through voltage-dependent channels, opened during phenylephrine stimulation. However, the nitroprusside action could be attributed to effect on the extrusion of calcium.

Animals↗
PubMed1998

Calcium antagonist properties of the bisbenzylisoquinoline alkaloid cycleanine.

The alkaloid cycleanine ([12aR-(12aR,24aR)]-2,3,12a,13,14,15,24,24a-octa hydro-5,6,17,18- tetramethoxy-1,13-dimethyl-8, 11:20,23-dietheno-1H,12H [1,10]dioxacyclooctadecino[2,3,4-ij:11,12,13-i'j']diisoquinolin e) was extracted from the bulbs of Stephania glabra (Roxb) Miers and its effects on cardiac and smooth muscle preparations were studied and compared to those of nifedipine (1,4-dihydro-2, 6-dimethyl-4-(2-nitrophenyl)-3,5-pyridine dicarboxylic acid dimethylesther). Cycleanine inhibited the KCl-induced contraction of rabbit aortic rings with higher potency than nifedipine. IC50s for cycleanine and nifedipine were 0.8 and 7.10(-9) M respectively. Cycleanine had minor effects on the norepinephrine-induced contraction of rabbit aortic rings. Cycleanine and nifedipine also depressed the contraction of rat ventricular preparations but with lower potency (IC50 = 3 and 0.03.10(-6) M respectively). Action potential duration of rat right ventricular strips was decreased by both compounds. L-type Ca-current (ICaL) of single rat ventricular cardiomyocytes was inhibited by cycleanine in a voltage- and frequency-dependent manner. With a higher potency nifedipine inhibited ICaL in a tonic and almost frequency-independent manner. The results suggest that cycleanine can act as a potent vascular selective Ca-antagonist.

Alkaloids↗
PubMed1998

Melatonin increases gene expression for antioxidant enzymes in rat brain cortex.

During the last years several reports have demonstrated that melatonin is a efficient free radical scavenger and general antioxidant. In addition, it has been shown that this neurohormone is able to increase the activity of glutathione peroxidase in rat brain cortex as well as the gene expression for some antioxidant enzymes in the Harderian gland of female Syrian hamster. Also, it is well known that brain cells are particularly exposed to free radicals, with antioxidant enzymes as the major defense mechanism that the brain uses to neutralize reactive oxygen species. The aim of the present study was to examine the influence of melatonin on gene expression for antioxidant enzymes in rat brain cortex. Our results clearly demonstrate that exogenously administered melatonin increases the levels of mRNA for glutathione peroxidase, copper-zinc superoxide dismutase, and manganese superoxide dismutase in this tissue. These stimulatory effects are observed after both acute and chronic treatment with this hormone, producing in the latter case the more marked increase. We therefore conclude that melatonin exerts an important role in providing indirect protection against free radical injury by stimulating gene expression for antioxidant enzymes. Consequently, melatonin could be considered as a potential therapeutic agent in some age-related neurodegenerative diseases where excessive free radical production has been implicated.

Animals↗
PubMed1998

Trypanosoma cruzi tubulin eliminated in the urine of the infected host.

In previous studies we have identified and characterized an 80-kDa Trypanosoma cruzi urinary antigen (UAg) eliminated during acute infection. Polyclonal antibodies raised against this antigen revealed by western blotting and immunoprecipitation analyses showed the existence of another antigenic component of 50-55 kDa in the UAg preparation. The antiserum was also used for screening of a T. cruzi expression library. Sequencing of inserts from selected cDNA clones showed high homology with the 3' end of the T.cruzi beta-tubulin gene sequence encoding for the C-terminus of the protein. The presence of T. cruzi tubulin in the UAg was confirmed by immunoprecipitation of a 50-55-kDa protein from 125I-labeled UAg with monoclonal antibodies (MAbs) to human alpha/beta-tubulin. Interestingly, MAbs recognized radiolabeled T. cruzi tubulin eliminated in the urine of infected mice 24 hr postinoculation of [35S]methionine-labeled viable trypomastigotes. Tubulin found in the urine proved to be of T. cruzi origin because this protein could not be identified in urinary specimens from uninfected animals or mice acutely infected with Leishmania infantum or Toxoplasma gondii. We conclude that tubulin is one of the parasite antigens eliminated in the urine of T. cruzi-infected hosts. This finding may be used to develop a noninvasive procedure for early diagnosis of Chagas' disease.

Amino Acid Sequence↗
PubMed1998

Family history of breast cancer as a predictor for fatal prostate cancer.

To examine the relation between family history of breast cancer in a mother or sister and a man's risk of fatal prostate cancer, we analyzed data from a prospective mortality study of adult men in the United States. During 12 years of follow-up, there were 3,141 deaths from prostate cancer in a cohort of 480,802 men who were cancer-free at study entry in 1982. Results from Cox proportional hazards models, adjusted for other risk factors, showed a modest increased risk of fatal prostate cancer associated with a family history of breast cancer (in the absence of a family history of prostate cancer) [rate ratio (RR) = 1.16; 95% confidence interval (CI) = 1.01-1.33]. The association was stronger among men younger than 65 years of age whose relatives were diagnosed with breast cancer before age 50 years (RR = 1.65; 95% CI = 0.88-3.10) and among Jewish men (RR = 1.73; 95% CI = 1.00-2.97). The increased risks observed in these subgroups may reflect genetic alterations underlying familial clustering of prostate and breast cancer.

Aged↗
PubMed1997

Use of ion trap gas chromatography-tandem mass spectrometry for detection and confirmation of anabolic substances at trace levels in doping analysis.

A procedure for detecting and confirming 23 anabolic substances and/or metabolites has been developed using a GC-MS-MS ion trap system in full-scan mode. The process used to select the precursor ion, and the optimization of the system parameters used to obtain the daughter ion spectra, are explained. Urine samples were prepared using solid-phase extraction and enzymatic hydrolysis, and after TMS derivatives had been formed, they were injected into the mass spectrometer. This method permits confirmation of the presence of anabolic substances at low ng ml(-1) levels without the need of further purification procedures on the samples. This procedure has been used on more than 2000 urine samples collected from sporting competitions and has made it possible to confirm more than 45 true positive cases which could not have been confirmed using routine GC-MS methods.

Anabolic Agents↗
PubMed1997

Regulatory role of CD95 ligation on human B cells induced in vivo capable of spontaneous and high-rate Ig secretion.

CD95 ligation elicits apoptotic signals in many cell systems. This study analyzes the effect of anti-CD95 mAb on human cells capable of spontaneous and high-rate Ig secretion. Such cells have been induced in vivo and represent a highly mature B cell stage. Addition of the anti-CD95 monoclonal antibody (mAb) CH11 to tonsil B cells inhibited 50-60% of their spontaneous Ig secretion. The effect was exerted early in the culture and could be reversed by a pre-treatment with a neutralizing mAb. N-acetyl-D-sphingosine (C2-ceramide), although not a close analog, also reduced Ig secretion to a similar extent. The inclusion of a tetrapeptide inhibitor for certain interleukin-1beta-converting enzyme proteases prevented the inhibitory effect of CH11 mAb on tonsil B cells. B cells capable of spontaneous Ab secretion obtained from blood of recently-immunized volunteers were also inhibited by CH11 mAb and C2-ceramide. In contrast, bone marrow (BM) B cells capable of spontaneous Ig secretion were unaffected by these agents. This CD95 ligation-mediated inhibition of tonsil and blood Ig-secreting B cells could not be reversed by cytokines with demonstrated activity on these B cells. Human mature B cells induced in vivo are identifiable as CD38hi cells. Flow cytometric analysis revealed that a fraction of tonsil CD38hi cells expressed low levels of CD95. Moreover, about 20% of these cells exhibited basal apoptosis, as defined by annexin V binding. This phenomenon was markedly increased by CD95 ligation. On the other hand, BM CD38hi cells showed neither CD95 expression nor CD95-induced annexin V binding. These data suggest that CD95 ligation might play a role in the control of human humoral responses by inducing apoptosis in susceptible mature B cells.

ADP-ribosyl Cyclase↗