Detection of antibodies to Candida albicans germ tubes in heroin addicts with systemic candidiasis.
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Adolescent↗
Biomedical subjects
F Rodríguez
Publications and source records attributed to F Rodríguez.
Changes in lymphocyte subsets in the bronchus-associated lymphoid tissue of goats naturally infected with different Mycoplasma species.
The distribution of cells containing lysozyme, S-100 protein, CD3, CD4, CD8, major histocompatibility complex class II antigen and immunoglobulin G (IgG) was analysed in the bronchus-associated lymphoid tissue (BALT) of goats naturally infected with three Mycoplasma species. This study included the immunohistochemical characterization of the pneumonic lesions of 18 goats (3-5 months old) infected with one of the following Mycoplasma species: M. mycoides ssp. mycoides, Large Colony type (goats no. 1-6), M. mycoides ssp. capri (goats no. 7-12) and M. capricolum ssp. capricolum (goats no. 13-18). Microscopically, infected animals showed a moderate broncho-interstitial pneumonia, characterized by lymphoid hyperplasia of the BALT and infiltration of mononuclear cells in the alveolar walls and airways. The main cellular type in the BALT was represented by CD3+ T lymphocytes, and the ratio of CD4+:CD8+ cells was > 2. The BALT showed large germinal centres mainly composed of IgG+ B lymphocytes, with numerous S-100+ follicular dendritic cells. The presence of follicular dendritic cells confirmed the high degree of organization of this lymphoid tissue. The immunohistochemical results showed that activated T lymphocytes, particularly in the CD4 subset, and IgG+ B cells, play a major role in the immune response of the caprine lung infected with these species of mycoplasmas.
Animals↗
Role of COX-2-derived metabolites in regulation of the renal hemodynamic response to norepinephrine.
The objective of this study was to examine the role of cylcooxygenase (COX)-2-derived prostaglandins (PG) in modulating the renal hemodynamic effects of norepinephrine (NE) during low or normal sodium intake. The relative contribution of each COX isoform in producing the PG that attenuate the renal NE effects during normal sodium intake was also evaluated. The renal response to three doses of NE (50, 100, and 250 ng. kg(-1). min(-1)) was evaluated in anesthetized dogs pretreated with vehicle, a selective COX-2 inhibitor (nimesulide), or a nonselective COX inhibitor (meclofenamate). Intrarenal infusion of the two lower doses of NE in vehicle-pretreated dogs with normal sodium intake (n = 8) elicited an increase in renal vascular resistance (RVR; 21 and 34%) without inducing changes in glomerular filtration rate (GFR). The highest dose of NE in this group induced a further increment in RVR (113%) and a decrease in GFR (33%). Pretreatment with nimesulide in dogs with normal sodium intake (n = 7) did not modify the NE-induced increments in RVR but enhanced the decreases in GFR induced by the three NE doses (12, 26, and 64%). The renal hemodynamic response to NE in meclofenamate-pretreated dogs with normal sodium intake (n = 7) was similar to that found in dogs pretreated with nimesulide. Infusion of the lowest dose of NE to vehicle-pretreated dogs with low sodium intake (n = 6) did not modify GFR and elicited an increase in RVR (42%). Infusion of the second and third doses of NE led to a decrease in GFR (35 and 91%) and a rise in RVR (82 and 587%). Infusion of the first two doses of NE in nimesulide-pretreated dogs with low sodium intake (n = 5) induced a fall in GFR (64 and 92%) and an increase in RVR (174 and 2,293%) that were greater (P < 0.05) than those induced by NE in vehicle-pretreated dogs. The elevation in the urinary excretion rates of PGE(2) and 6-keto-PGF(1alpha) elicited by NE was prevented in the nimesulide-pretreated dogs. Our results show that COX-2 inhibition potentiates the renal hemodynamic effects of NE and propose that the PG involved in modulating them are mainly derived from COX-2 activity.
6-Ketoprostaglandin F1 alpha↗
Irritable bowel syndrome: attrition rates of patients identified at primary care centers during a 50-week period versus those identified in hospitals in a phase II clinical trial.
Although most irritable bowel syndrome (IBS) patients are managed in primary care centers, most trials are performed in the hospital setting. A successful recruitment strategy is important for trial completeness and its external validity. To this end, it was important to assess the attrition rates of patients identified at primary care centers and hospitals in this phase II trial conducted in the outpatient clinics of 16 hospitals. IBS patients were identified through review of the centers' files (prescreening). After a 2-week single-blind placebo screening phase, the patients were randomized to receive an investigational drug or a matched placebo for 24 weeks (dose-ranging study). Thereafter, the patients were invited to participate in a 24-week, double-blind extension study. The attrition rates among patients identified at hospitals (group A) and at primary care centers (group B) were compared in each study phase and during the 50-week period by bivariate and multivariate regression analyses. Group A and B patients were identified in 13 hospitals and 51 primary care centers, respectively. Of 1,001 prescreened patients, 302 started the screening phase with attrition rates of 35% (of 132 patients) and 25% (of 170) for groups A and B, respectively (p = 0.054). The attrition rate during the double-blind phase was 14%. Of the 184 patients who completed the dose-ranging study, 39 (group A: 32%; group B: 14%; p = 0.005) did not wish to participate in the extension study. The attrition rate in the extension study was 15%. The overall attrition rates during the 50-week period were 67% and 53% (p = 0.016) for groups A and B, respectively. The multivariate regression analysis showed that the screening phases (p = 0.000) and unwillingness to participate in the extension study (p = 0.007) had the highest impact on attrition rates. We conclude that referring patients identified in primary care centers to hospitals seems appropriate to ensure potentially eligible patients for IBS trials. Patients identified in primary care centers are more likely than those identified in hospitals to participate in a 24-week extension study, which may be due to their positive feelings about being treated in a hospital rather than being referred back to their original primary care center. This strategy may be considered in future trials since, with a reasonably low attrition rate, it would enhance the external validity of the results obtained.
Adult↗
A short stereoselective total synthesis of the fusarium toxin equisetin.
A short stereoselective synthesis of the fusarium toxin equisetin, an N-methylserine-derived acyl tetramic acid and potent inhibitor of HIV-1 integrase enzyme, is described using as the key step a stereoselective lithium perchlorate mediated intramolecular Diels-Alder reaction of a fully conjugated E,E,E-triene with a trisubstituted gamma,delta-unsaturated beta-ketothioester.
Acetylation↗
Five- and Seven-Membered Rings from Alkenyl(methoxy)carbene Complexes and Methyl Ketone Enolates This work was supported by DGICYT (Grant PB97-1271).
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Journal Article↗
Reversal learning deficit in a spatial task but not in a cued one after telencephalic ablation in goldfish.
The fish telencephalon seems to be involved in spatial learning and memory in a similar manner to the hippocampus of the land vertebrates. For instance, telencephalon ablated goldfish are impaired in the post-operative retention of a 'spatial constancy' task, which requires the use of mapping strategies, but not in a directly cued task in which responses are based in a guidance strategy. In this regard, previous experiments showed that intact goldfish trained in the spatial constancy task presented considerable behavioral flexibility, as they showed fast reversal learning, that is, they required less training compared with animals trained in the directly cued task and made a lower number of errors to master the reversal than in acquisition. The purpose of the present work was to investigate if the goldfish telencephalon is involved in the faster reversal learning of the animals trained in the spatial constancy task. Goldfish with bilateral telencephalic ablation, sham operated or intact, were trained in the spatial constancy task or in the directly cued task. Telencephalic ablation selectively impaired reversal learning in the animals trained in the spatial constancy procedure. Ablated animals in this procedure reversed more slowly than control animals. By contrast, telencephalic ablation did not produce any significant deficit during reversal in the animals trained in the directly cued task. These results provide additional evidence that the fish telencephalon, as the land vertebrate hippocampus, plays a crucial role in the use of flexible spatial representations.
Animals↗
[Total arterial myocardial revascularization with both mammary arteries without extracorporeal circulation].
INTRODUCTION: Tector has described the off-pump total arterial revascularization technique, using multiple anastomosis with both internal thoracic arteries. To reduce surgical morbid-mortality, we have proposed the use of this technique without extracorporeal circulation. PATIENTS AND METHODS: From April, 1998 the off-pump < > technique was performed in 92 patients, 74 male (80%) and 18 female (20%), with a mean age of 64.9+/-8.1 years (42-78). Preoperative angiography demonstrated triple-vessel disease in 58 (63%) patients, and left main disease was present in 19 (20.5%) patients. Forty patients (43.5%) showed unstable angina, 24 patients (26%) significant peripheral vascular disease, and 26 (28%) diabetes mellitus. Both internal thoracic arteries were harvested using the skeletonization technique and were used like a < > graft. The flow in the graft was measured using a flowmeter, and in 24 (26%) patients by angiographic study. RESULTS: A total of 274 distal anastomoses were performed, 122 (44.6%) in the lateral or inferior wall, and 69 (25.2%) were sequential, with an average of 2.98 bypass/patient. In 59.8% of the patients a triple bypass was performed, 22% double bypass, 17% cuadruple bypass and 1 patient a quintuple bypass. During the initial six hours 64.9% of patients were extubated. Only one patient (1.1%) needed intraaortic ballon pumping and 3 (3.2%) inotropics during the postoperative course. Hospital mortality was 3 (3.2%) patients. Reoperation for bleeding was needed in just one patient (1.1%), and 78.3% of patients were not transfused. Mediastinitis occurred in 3 patients (3.2%). Postoperative stroke was not observed. At 7.7+/-2.8 months of mean follow-up all patients were free of symptoms and the global patency rate of 94%. CONCLUSIONS: Off-pump Tector technique appears to be safe, offering a complete arterial revascularization and showing a reduction of surgical morbidity.
Adult↗
Heat treatment of beta-lactoglobulin: structural changes studied by partitioning and fluorescence.
Functional properties of whey protein concentrates (WPC) are primarily dependent on the degree of denaturation of beta-lactoglobulin (beta-LG), the major globular whey protein. Irreversible modifications in the tertiary structure and association state of beta-LG after heat treatment were studied by partition in aqueous two-phase systems and fluorescence quenching. Partitioning of preheated beta-LG in two-phase systems containing 5% (w/w) poly(ethylene glycol) and 7% (w/w) dextran, between pH 6.0 and7.0, are appropriately related with the intensity of heat treatment. An increase in the partition coefficient of beta-LG was observed with increasing temperature of heat treatment. On the other hand, fluorescence quenching of beta-LG by acrylamide was used to study the conformational flexibility of the protein at pH values between 4. 0 and 9.0. The values of bimolecular quenching rate constant (k(q)) obtained showed that beta-LG appears to be more flexible at high pH values, while at low pH the protein assumes a more compact form. The efficiency of acrylamide quenching on preheated beta-LG was substantially more pronounced than for the untreated protein. This difference can be ascribed to the presence of unfolded monomers and aggregates of denatured molecules formed after heat treatment, whose tryptophanyl residues are more exposed to the solvent. In conclusion, the results suggest that partition studies in aqueous two-phase systems and fluorescence quenching are very useful tools to detect changes in conformation and aggregation of beta-LG induced by heat treatment.
Fluorescence↗
Dissociation of place and cue learning by telencephalic ablation in goldfish.
This study examined the spatial strategies used by goldfish (Carassius auratus) to find a goal in a 4-arm maze and the involvement of the telencephalon in this spatial learning. Intact and telencephalon-ablated goldfish were trained to find food in an arm placed in a constant room location and signaled by a local visual cue (mixed place-cue procedure). Both groups learned the task, but they used different learning strategies. Telencephalon-ablated goldfish learned the task more quickly and made fewer errors to criterion than controls. Probe trials revealed that intact goldfish could use either a place or a cue strategy, whereas telencephalon-ablated goldfish learned only a cue strategy. The results offer additional evidence that place and cue learning in fish are subserved by different neural substrates and that the telencephalon of the teleost fish, or some unspecified structure within it, is important for spatial learning and memory in a manner similar to the hippocampus of mammals and birds.
Animals↗
Immunohistochemical characterization of lung lesions induced experimentally by Mycoplasma agalactiae and Mycoplasma bovis in goats.
Goats aged 3 months were inoculated with a recent isolate of Mycoplasma agalactiae (five animals) or Mycoplasma bovis (five animals) by a combined (intratracheal+intranasal) route. Two control goats were inoculated by the same route with sterile mycoplasma broth. Animals were killed 14 or 21 days after infection. At necropsy, tracheal and lung tissue was taken for pathological and immunohistochemical examination to determine changes in the lymphocyte subpopulations in the bronchus-associated lymphoid tissue (BALT). Consolidation of the lungs was not observed in any animal. M. agalactiae or M. bovis was recovered from the respiratory tract and lung of all but two infected animals. Both Mycoplasma spp. induced a moderate bronchointerstitial pneumonia, characterized by lymphoid hyperplasia of the BALT and infiltration of mononuclear cells into the alveolar walls. The predominant phagocytic cell in the pulmonary parenchyma and the airways was the macrophage. The main cellular type in the BALT was the CD3(+)T lymphocyte, and the ratio of CD4(+): CD8(+)cells was >1. It is likely that cellular immune mechanisms, through the activation of CD4(+)T lymphocytes, plays a prominent role in the acute and subacute phase of these infections.
Animals↗
Renal effects of prolonged cyclooxygenase inhibition when angiotensin II levels are elevated.
We examined the renal functional and hemodynamic changes induced by prolonged cyclooxygenase (COX) inhibition when angiotensin II levels are elevated during several consecutive days. The effects induced by the infusion of either initially subpressor or pressor angiotensin II doses (1 and 5 ng/kg/min) were examined in dogs with or without the simultaneous infusion of meclofenamate (5 microg/kg/min). Experiments were performed in conscious permanently instrumented dogs. Infusion of the lower angiotensin II dose alone (n = 6) caused a late 12+/-2% increase in arterial pressure, a 25+/-6% decrease in renal blood flow (RBF), and a transitory decrease in urinary sodium excretion. COX inhibition reduced the hypertension and renal vasoconstriction, but enhanced the sodium retention, induced by the lower dose angiotensin II infusion (n = 6). The higher angiotensin II dose (n = 6) caused a 25+/-4% increase in arterial pressure, a 24+/-5% decrease in RBF, and a transitory decrease in urinary sodium excretion. Finally, COX inhibition did not modify the renal effects elicited by the higher angiotensin II dose (n = 6). The results of this study suggest that endogenous prostaglandins play an important role in the regulation of the renal and systemic changes induced by prolonged administration of initially subpressor angiotensin II doses. It has also been demonstrated that prolonged COX inhibition does not modify the renal functional and hemodynamic changes elicited by the long-term infusion of a pressor angiotensin II dose.
Angiotensin II↗
Release of nitric oxide after acute hypertension.
We have shown that NO production, assessed by measuring changes in plasma nitrate concentration, is down-regulated when blood pressure falls. This study intended to determine first, whether NO-derived plasma nitrate varies in response to increases in blood pressure induced by different mechanical and pharmacologic stimuli, including angiotensin II and catecholamines; and second, specifically to study the interaction between angiotensin II and NO production. An intravenous infusion (4-10 min) of norepinephrine (7.5 microg/kg/min), phenylephrine (30 microg/kg/min), or angiotensin II (0.3 and 3 microg/kg/min) caused hypertension accompanied by an increase in plasma nitrate, as assessed by high-performance capillary electrophoresis. Mechanical hypertension elicited by aortic occlusion also was accompanied by an increase in plasma nitrate. Angiotensin II (0.03, 0.3, and 3 microg/kg/min, 10 min) dose-dependently increased blood pressure. The intermediate and high dose, but not the low dose, of angiotensin II increased plasma nitrate concentration. N(G)-nitro-L-arginine methyl ester (L-NAME) lowered the basal concentration of plasma nitrate, abolished the increase in plasma nitrate elicited by angiotensin II and norepinephrine, and potentiated the pressor effect of the low dose of angiotensin II, although this dose did not increase NO production. L-NAME also potentiated the pressor effects of the intermediate dose of angiotensin II. This study demonstrates that an augmented systemic production of NO, measured as an increase in plasma nitrate, takes place after acute hypertension. The results of this study suggest that an increase in NO generation occurs when angiotensin II hypertension exceeds a certain limit, below which the basal production of NO is sufficient to compensate the vasoconstriction.
Acute Disease↗
Role of cyclooxygenase-2-derived metabolites and nitric oxide in regulating renal function.
The aim of this study was to examine the relative contribution of both cyclooxygenase (COX) isoforms in producing the prostaglandins (PG) involved in the regulation of renal function, when nitric oxide (NO) synthesis is reduced. In anesthetized dogs with reduction of NO synthesis, the renal effects of a nonisozyme-specific COX inhibitor (meclofenamate) were compared with those elicited by a selective COX-2 inhibitor (nimesulide) before and during an extracellular volume expansion (ECVE). Intrarenal N(G)- nitro-L-arginine methyl ester (L-NAME) infusion (1 microg x kg(-1) x min(-1); n = 6) did not elicit renal hemodynamic changes and reduced (P < 0.01) the renal excretory response to ECVE. Intravenous nimesulide (5 microg x kg(-1) x min(-1); n = 6) did not modify renal hemodynamic and reduced (P < 0. 05) sodium excretion before ECVE. Simultaneous L-NAME and nimesulide infusion (n = 7) elicited an increment (37%) in renal vascular resistance (RVR; P < 0.05) before ECVE and no hemodynamic changes during ECVE. The reduced excretory response elicited by L-NAME and nimesulide was similar to that found during L-NAME infusion. Finally, simultaneous L-NAME and meclofenamate infusion (10 microg x kg(-1) x min(-1); n = 7) induced an increase in RVR (91%, P < 0.05), a decrease in glomerular filtration rate (35%, P < 0.05), and a reduction of the renal excretory response to ECVE that was greater (P < 0.05) than that elicited by L-NAME alone. The results obtained support the notion that PG involved in regulating renal hemodynamic and excretory function when NO synthesis is reduced are mainly dependent on COX-1 activity.
Animals↗
Renal changes induced by a cyclooxygenase-2 inhibitor during normal and low sodium intake.
Cyclooxygenase-2 (COX-2) has been identified in renal tissues under normal conditions, with its expression enhanced during sodium restriction. To evaluate the role of COX-2-derived metabolites in the regulation of renal function, we infused a selective inhibitor (nimesulide) in anesthetized dogs with normal or low sodium intake. The renal effects elicited by nimesulide and a non-isozyme-specific inhibitor (meclofenamate) were compared during normal sodium intake. In ex vivo assays, meclofenamate, but not nimesulide, prevented the platelet aggregation elicited by arachidonic acid. During normal sodium intake, nimesulide infusion (n=6) had no effects on arterial pressure or renal hemodynamics but did reduce urinary sodium excretion, urine flow rate, and fractional lithium excretion. In contrast, nimesulide administration increased arterial pressure and decreased renal blood flow, urine flow rate, and fractional lithium excretion during low sodium intake (n=6). COX-2 inhibition reduced urinary prostaglandin E(2) excretion in both groups but did not modify plasma renin activity in dogs with low (8.1+/-1.1 ng angiotensin I. mL(-1). h(-1)) or normal (1.8+/-0.4 ng angiotensin I. mL(-1). h(-1)) sodium intake. Meclofenamate infusion in dogs with normal sodium intake (n=8) induced a greater renal hemodynamic effect than nimesulide infusion. These results suggest that COX-2-derived metabolites (1) are involved in the regulation of sodium excretion in dogs with normal sodium intake, (2) play an important role in the regulation of renal hemodynamic and excretory function in dogs with low sodium intake, and (3) are not involved in the maintenance of the high renin levels during a long-term decrease in sodium intake.
Animals↗
Immunohistopathologic characterization of a dermal melanocytoma-acanthoma in a German Shepherd Dog.
A cutaneous melanocytoma-acanthoma in a 2-year-old female German Shepherd Dog was characterized by the presence of two populations of neoplastic cells: epithelial and melanocytic. The epithelial component consisted of nests of well-differentiated stratified squamous epithelium closely associated with neoplastic melanocytes. The epithelial cells immunoreacted with both monoclonal and polyclonal anti-cytokeratin antibodies, and immunoreaction to S-100 protein and vimentin was observed in the melanocytic cells. This rare pigmented skin neoplasm of the dog apparently has a benign behavior.
Animals↗
[Biochemical control after external radiotherapy in localized prostatic cancer: results of a modern cohort].
PURPOSE: The present study reports biochemical outcomes of a modern series of patients with localised prostate cancer treated with external beam radiation therapy, and analyses the implications of the nadir PSA levels in monitoring outcome after treatment. METHODS: From March 1993 to March 1997, eighty three patients with clinical stages T1-T3 NxM0 prostate cancer received definitive external radiation therapy, median dose 66 Gy (range 60 to 68 Gy). Adjuvant androgen deprivation was associated in 53 high risk patients. Initial response to treatment was defined as a decrease of serum PSA to levels of < or = 1.5 ng/ml, and biochemical failure as three consecutive PSA rises over post-treatment nadir PSA value. RESULTS: The 3-year actuarial BDFS was 78% +/- 7 for the whole series, 74% +/- 12 for patients treated with radiotherapy alone, and 71% +/- 10 for high risk patients treated with combination therapy (p = 0.27). Only nPSA emerged as a potential indicator of biochemical control. The probability of BDFS at 3 years was 82%, 83% and 40% for nPSA of < or = 1 ng/ml, 1-2 ng/ml and > 2 ng/ml respectively (p = 0.0409). In multivariate analysis, this correlation was independent on the effect of other variables and persisted after adjusting for the effect of hormonal therapy (p = 0.0540). CONCLUSION: Radiation therapy is a potentially curative treatment for prostate carcinoma. Our data indicate that the nadir PSA value after radiation can be an excellent early determinant of outcome.
Adenocarcinoma↗
Rapid method for the detection of anti-HCV antibodies in patients with chronic hepatitis C.
OBJECTIVE: to evaluate the usefulness of a simple, rapid, qualitative technique (MedMira Rapid Test) to detect antibodies against hepatitis C virus (HCV) and compare this approach with an immunometric technique in patients with chronic hepatitis C infected with different genotypes. METHODS: anti-HCV antibodies were determined with the MedMira rapid technique and an immunometric method in samples from 138 patients with chronic hepatitis C infected with different HCV genotypes, and in 50 samples from healthy individuals. RESULTS: the MedMira rapid technique detected anti-HCV antibodies in 135 (98%) of 138 serum samples from patients with chronic hepatitis C, whereas the immunometric method gave positive results in all 138 samples. Three of the 138 anti-HCV-positive samples identified with the immunometric method and confirmed by inmunoblotting were repeatedly negative with the MedMira rapid technique. Two of these samples were genotype 1 and the third was not genotyped. All samples from the control group were negative for anti-HCV antibodies by both methods. The sensitivity and specificity of the MedMira rapid technique relative to the immunometric technique were 98% and 100% respectively. CONCLUSION: the MedMira rapid technique is a quick, specific and sensitive method that is easy to use by nonspecialized personnel, and is a good alternative to other, slower methods for the diagnosis of chronic hepatitis C.
DNA, Viral↗