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Biomedical subjects

L Moreno

Publications and source records attributed to L Moreno.

At least 55 records · Page 3Linked to original sources
PubMed1998

Analysis of the cross-reactivity between BtM and Der p 5, two group 5 recombinant allergens from Blomia tropicalis and Dermatophagoides pteronyssinus.

BACKGROUND: In tropical climates, sensitization to Bloma tropicalis and Dermatophagoides pteronyssinus is high and mainly directed to species-specific allergens. There is some cross-reactivity between extracts of these mites, probably due to the group 5 allergens that have high sequence homology. OBJECTIVE AND METHODS: We used the radioallergosorbent test (RAST), RAST inhibition and immunoblotting inhibition experiments to investigate the cross-reactivity between the recombinant allergens BtM and Der p 5, expressed as glutathione S-transferase fusion proteins, to detect the epitopes involved and to analyze the importance of this cross-reactivity. RESULTS: Seventy-nine percent of 48 patients sera were RAST positive to both recombinants, with a strong correlation (r = 0.8, p<0.0001). BtM inhibited 25 and 21.1% of IgE-binding to B. tropicalis and D. pteronyssinus extracts respectively and Der p 5 inhibited 22 and 24% of IgE-binding to D. pteronyssinus and B. tropicalis extracts. Furthermore, BtM inhibited 74.5% of IgE binding to Der p 5 and Der p 5 inhibited 72.4% of IgE-binding to BtM. RAST inhibition with BtM-derived synthetic peptides showed that peptide 4 (residues 35-50) and peptide 5 (residues 46-61) inhibited 37 and 16% of IgE-binding to BtM while peptides 5 and 2 (residues 14-30) were able to inhibit the IgE binding (32 and 28%, respectively) to Der p 5. CONCLUSION: There is cross-reactivity between BtM and Der p 5, which explains almost all the cross-reactivity between the two mite extracts. This cross-reactivity seems to be related to epitope(s) at the C-terminal segment of these allergens.

Allergens↗
PubMed1998

First experience and technical aspects of isolated liver perfusion for extensive liver metastasis.

BACKGROUND: New drugs and modalities for locoregional tumor treatment in recent years may offer new potential for isolated liver perfusion in patients with nonresectable liver tumors. The purpose of this study was to prove the feasibility of arterial isolated liver perfusion and to assess the tolerance of perfusion with high-dose tumor necrosis factor (TNF). METHODS: Twelve patients with extensive liver metastases previously treated unsuccessfully with systemic chemotherapy underwent isolated hyperthermic liver perfusion using a heart-lung machine. High doses of mitomycin were administered in the first six and a combination of TNF and melphalan in the last six patients. RESULTS: No operative death occurred and no direct postoperative liver failure was observed in any patient. In cases of variations of the arterial hepatic blood supply, the perfusion was done through the splenic artery or an angiography catheter. Histologic analysis of tumor biopsy specimens obtained on the first postoperative day revealed major tumor necrosis in 8 of 12 patients. CONCLUSIONS: Isolated arterial perfusion of the liver is a complex surgical procedure that is feasible in patients with anatomic variations of the hepatic artery. The remarkable histologic response to perfusion in several pretreated patients, especially after application of high-dose TNF and melphalan, suggests that this modality is very effective in tumor killing.

Adult↗
PubMed1998

[Omeprazole plus 2 antibiotics for the eradication of H. pylori, are 5 days of treatment sufficient?].

OBJECTIVE: Combinations of omeprazole plus two antibiotics for seven days have repeatedly been studied and high Helicobacter pylori eradication rates have been obtained, ranging from 80% and 90% in our country. Our objective was to verify whether length of such therapies (with omeprazole, metronidazole and clarithromycin or amoxicillin) can be shortened to five days with no loss of efficacy. METHODS DESIGN: randomized clinical trial. PATIENTS: forty-eight consecutive patients with duodenal ulcer were prospectively studied. The exclusion criteria were previous administration of antibiotics, bismuth or gastroerosive drugs, and associated diseases. During the initial endoscopy biopsy specimens from antrum and corpus were obtained (haematoxylin-eosin). Two therapies were administered for five days: omeprazole (20 mg/12 h) and clarithromycin (500 mg/12 h) plus metronidazole (500 mg/12 h) (n = 24) or amoxicillin (1 g/12 h) (n = 24). One month after therapy was completed a new endoscopy was performed, biopsy specimens were obtained, and the 13C-urea breath test was performed. Compliance of therapy was assessed by questioning the patient and counting the residual medication. DATA ANALYSIS: multiple logistic regression and "intention-to-treat" analysis. OUTCOME VARIABLE: eradication was defined as the absence of H. pylori by all diagnostic methods. RESULTS: Mean age +/- SD was 48 +/- 10 years, 73% were males. Twenty-three patients in each group completed the protocol and the distribution of investigated parameters was similar in both groups. Eradication was obtained in 91.7% (95% CI = 74%-98%) in the metronidazole group and 70.8% (51%-85%) in the amoxicillin group (chi 2 = 2.19; p = 0.13). In the multivariate analysis, OR for the effect of type of therapy on eradication was 4.5 (CI = 0.83-24.7; p = 0.077). No relevant secondary effects were reported. The most common secondary effect was a metallic taste of medication, which was perceived by half of patients in each group. CONCLUSION: The combination of omeprazole, clarithromycin, and metronidazole for only five days has a high eradicating efficacy (approximately 90%), similar to that obtained in previous studies with seven days of therapy. Nevertheless, the association of omeprazole, clarithromycin, and amoxicillin should probably be administered at least for one week to reach an optimal eradicating efficacy.

Amoxicillin↗
PubMed1997

Outcomes of stroke patients in Medicare fee for service and managed care.

CONTEXT: Increasing numbers of Medicare beneficiaries have been enrolling in health maintenance organizations (HMOs) because HMO participation reduces out-of-pocket expenses, and the federal government views HMOs as a way to contain Medicare costs. However, results comparing outcomes and quality of care in HMOs vs fee for service (FFS) have been mixed, and outcomes after stroke have not been adequately assessed. OBJECTIVE: To compare discharge destinations and survival rates following stroke in Medicare HMOs with similar FFS settings. DESIGN: An observational study for 2 groups evaluating stroke patients' discharge destinations and survival times from the date of hospital admission. SETTING: A total of 19 HMOs were selected from 12 states. The FFS sample was drawn from the same geographic areas. PATIENTS: The sample included 402 HMO patients from 71 hospitals and 408 FFS patients from 60 hospitals. PROCESS AND OUTCOME MEASURES: Data were abstracted from medical records on demographics, clinical characteristics of stroke, comorbid illnesses, and discharge destinations following hospitalization. Data on survival were obtained from Medicare files and included 25 to 37 months of follow-up (median, 30.4 months, HMO; 31.1 months, FFS) from the date of hospital admission. RESULTS: There were 109 patients who died during the hospitalization (49 HMO, 12.2%; 60 FFS, 14.7%), and a total of 410 patients had died by the end of follow-up (191 HMO, 47.5%; 219 FFS, 53.7%). Approximately one fourth of both groups had do-not-resuscitate orders (HMO, 25.4%; FFS, 27.9%; P=.68). After controlling for age, marital status, and characteristics of dependency at discharge, HMO patients were more likely than FFS patients to be sent to nursing homes (HMO, 41.8%; FFS, 27.9%; P=.001) and less likely to be discharged to rehabilitation hospitals or units (HMO, 16.2%; FFS, 23.4%; P=.03). At follow-up, no significant differences in relative risk of dying were found between HMO and FFS groups (relative risk, 0.96; 95% confidence interval, 0.73-1.26; P=.77). CONCLUSIONS: Patients in Medicare HMOs who experience strokes are more likely to be discharged to nursing homes and less likely to go to rehabilitation facilities following the acute event. However, they have similar survival patterns compared with comparable patients in FFS settings after adjusting for other factors.

Aged↗
PubMed1997

Lack of association of catechol-O-methyltransferase (COMT) functional polymorphism in bipolar affective disorder.

Abnormal catecholamine transmission has been implicated in the pathogenesis of mood disorders. Consequently, alterations in genes that are involved in catecholamine metabolism could be potential candidates for bipolar affective disorder (BPD) vulnerability. One such candidate is catechol-O-methyltransferase (COMT). A functional polymorphism has recently been characterized that is responsible for substantial variability in COMT enzymatic activity. A relatively low activity allele is associated with a methionine residue at amino acid 158 of membrane bound COMT whereas a high activity variant has a valine at this site. We have now screened 63 unrelated patients with BPD for this functional polymorphism. However, no significant association was detected. This suggests that the codon 158 COMT polymorphism is not a susceptibility gene in BPD.

Alleles↗
PubMed1997

Role of the endothelium in the relaxation induced by propofol and thiopental in isolated arteries from man.

Induction of anaesthesia with intravenous propofol and thiopental is often accompanied by hypotension. This study evaluates whether propofol and thiopental induce relaxation of isolated arteries from man and whether this effect is modulated by the endothelium. Mesenteric artery rings (with and without endothelium) from 12 patients were placed in organ baths and precontracted with phenylephrine before addition of propofol (10(-3) M) or thiopental (10(-3) M). Relaxation induced by propofol and thiopental was evaluated for rings with intact endothelium in the presence of the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10(-4) M) or the cyclooxygenase inhibitor indomethacin (10(-5) M). The vasodilator effect of propofol was similar for intact and denuded endothelium rings whereas the relaxation induced by thiopental was significantly attenuated in denuded-rings. In intact endothelium rings, L-NAME and indomethacin caused marked inhibition of the relaxation induced by thiopental, but not that induced by propofol. These results suggest that propofol induces endothelium-independent relaxation of isolated mesenteric arteries in man, whereas thiopental causes endothelium-dependent relaxation mediated by nitric oxide and prostaglandins.

Aged↗
PubMed1997

[The combined application of visual evoked potentials and the quantified electroencephalogram improve discrimination of cerebral maturity].

INTRODUCTION AND OBJECTIVE: The aim of this job is to evaluate brain maturation by means of Electroencephalogram (EEG) and Visual Evoked Potentials stimulated with flash (VEP-flash) quantitative analysis techniques. MATERIAL AND METHODS: The transversal study is made on a sample of 96 subjects in which EEG and VEP-flash, first isolated and then joining both, are analyzed. The selection of spectral parameters was done taking care of all the subjects were selected in the sense of maximizing brain maturation discrimination. Multivariate analysis techniques for classifying subjects were used. EEG and VEP-flash variables were selected with the linear discriminant analysis. In the EEG case the variables take into account, as a reference, either the median of the power spectrum or either the time instant in which the spectral power in every band reaches its maximum value. In the joined EEG-VEP-flash the VEP variables which give more information were related with the slopes and distances between the basic peaks of the evoked response (N1, P1 and N2) and age. For brain maturation evaluation the variables in the occipital channels are sufficient, being those of the right hemisphere the most diagnostic significative ones. CONCLUSION: The joined use of EEG and VEP-flash means an improvement in the maturative level discrimination regarding to the isolated consideration of any of them. Variables obtained from the EEG-VEP-flash are enough for brain maturation evaluation.

Adolescent↗
PubMed1997

[A study of cerebral maturity by means of quantitative analysis of the electroencephalogram].

INTRODUCTION AND OBJECTIVE: The objective of this study is to evaluate cerebral maturity by means of quantitative analysis techniques applied to the electroencephalogram (EEG). MATERIAL AND METHODS: A transversal study of cerebral maturity was carried out in 403 persons who had undergone an EEG. A previous pilot study had been carried out of 103 persons. A series of spectral parameters of the EEG were selected so that all those studied were in the most similar conditions possible. Different frequency bands were analyzed choosing the one with best discrimination of the maturity aspect. Classification of the different levels of cerebral maturity was done with the help of multivariant analysis. The value of the median of the frequencies and the spectrum of relative potencies at the moment when a frequency band is at a maximum are the parameters which evolve best with age and best discriminate maturity Spectral analysis allows selection of the frequency bands most suitable to the problem. Working with two frequency bands is sufficient to evaluate cerebral maturity. RESULTS: The variables obtained in the occipital channels were sufficient for evaluation of cerebral maturity. Those of the right hemisphere were more significant for diagnosis. The occipital channels are the most relevant in the study of cerebral maturity. CONCLUSIONS: The neuronal network is the most efficient classifier for classification of different groups of maturity The next most efficient method is by quadratic discriminant analysis. Consideration of the variables, taking into account the factors of stability and regularity of the EEG signals improves discrimination with respect to the average of those recorded during the entire procedure.

Adolescent↗
PubMed1996

Anatomical differences in responsiveness to vasoconstrictors in the mesenteric veins from normal and portal hypertensive rats.

The present study evaluates the effects of pre-hepatic portal hypertension, induced in rats by partial portal vein ligation, on the responsiveness of rostral (proximal) and caudal (distal) rings from the mesenteric vein. The anatomical origin of the sample influenced the response to vasoconstrictors in sham-operated animals, and this pattern of reactivity was specifically modified in portal-ligated rats. In veins from sham-operated rats, contraction induced by a submaximal concentration of KCl (60 mM) was greater in proximal than in distal rings. Vasopressin and 5-hydroxytryptamine contracted mainly distal rings, methoxamine showed a greater effect on proximal rings, and endothelin-1 and angiotensin-II contracted vein rings independently of their anatomical origin. In veins from portal hypertensive rats, response to KCl (60 mM) were increased in distal rings, and all rings exhibited enhanced reactivity to vasopressin and 5-hydroxyptyptamine as well as attenuation of the response to methoxamine. Responses to endothelin-1 were decreased in proximal vein rings from portal hypertensive rats whereas responses to angiotensin-II were not influenced by the anatomical origin. Incubation with atropine, propranolol or indomethacin, did not modify the responses to vasopressin and 5-hydroxytryptamine in tissues from either sham-operated or portal hypertensive animals. Likewise, the hyporeactivity to methoxamine and endothelin-1 in rings from portal hypertensive rats persisted in the presence of the nitric oxide inhibitor NG-nitro-L-arginine methyl ester. These results suggest the physiological existence of anatomical differences in the responsiveness to vasoconstrictors throughout the mesenteric vein and that changes in the responsiveness of the mesenteric vein induced by portal hypertension are specific for each agonist and possibly result from individual variations at a receptor or post-receptor level.

Animals↗
PubMed1996

Nitric oxide-mediated beta 2-adrenoceptor relaxation is impaired in mesenteric veins from portal-hypertensive rats.

BACKGROUND & AIMS: beta-Adrenergic relaxation seems to be mediated by nitric oxide. The aim of this study was to evaluate changes induced by portal hypertension in beta 2-adrenergic vasorelaxation. METHODS: Isolated rat mesenteric veins were relaxed by salbutamol, and nerve-mediated vasocontractions were induced by electrical field stimulation. Responses were evaluated in the presence of NG-nitro-L-arginine methyl ester (L-NAME) or tetrodotoxin. Immunocytochemical techniques were used for localization of neuronal NO synthase. RESULTS: Salbutamol-induced relaxations were decreased in rings from portal-hypertensive animals. L-NAME reduced these relaxations, but its effects were more pronounced in sham-operated rats. Tetrodotoxin decreased the effect of salbutamol only in rings from sham-operated animals. Combination of L-NAME and tetrodotoxin did not exert a greater effect than either of these agents alone. Veins from portal-hypertensive animals were more sensitive to S-nitroso-N-acetyl penicillamine. L-NAME increased vasocontractions by electrical stimulation only in rings from sham-operated rats. Veins from portal-hypertensive animals exhibited a specific degeneration of NO-containing nerve endings. CONCLUSIONS: beta 2-Adrenergic relaxation is impaired in mesenteric veins from portal-hypertensive rats, possibly as a result of a defective neuronal release of NO.

Adrenergic beta-Agonists↗
PubMed1996

The effect of sodium and ultrafiltration modelling on plasma volume changes and haemodynamic stability in intensive care patients receiving haemodialysis for acute renal failure: a prospective, stratified, randomized, cross-over study.

BACKGROUND: Haemodynamic stability in intensive care unit (ICU) patient with acute renal failure (ARF) during intermittent dialytic support has been the focus for several variations to dialysis delivery. Indeed this has been noted by many as a possible cause for prolonged renal dysfunction created by repeated hypotensive renal insult, as well as a reason for the lower delivered dialysis dose afforded. End-stage renal failure patients supported by intermittent dialysis have benefitted from variable sodium dialysate and variable ultrafiltration rate protocols. The current study has focused upon the response to these dialysis variations in the ICU ARF patient. METHODS: Successive ICU patients with defined characteristics of ARF requiring dialytic support were entered into a prospective, stratified (by Cleveland Clinic Foundation ARF Acuity Score), randomized, crossover designed study to evaluate haemodynamic effects and need for interaction during dialysis therapy delivering a fixed dialysis dose based upon area kinetic analysis. Subjects were supported either by a fixed dialysate sodium (140 meq/dl) and fixed ultrafiltration rate (Protocol A), or a variable sodium dialysate (160-140 meq/dl) and variable ultrafiltration (50% UF during the first third of treatment time, 50% UF over the last two thirds treatment time) (Protocol B). After three sessions, the patients were crossed to the other protocol, and if continued, after three sessions returned to the original protocol. Mean arterial pressures, Cardiac output, serum electrolytes, serum albumin, and relative blood volume changes were measured. Frequency of nursing intervention, quantity and type of volume replacements as well as pressor agent use was standardized, documented and compared. RESULTS: Ten ARF patients (age: 64.2 +/- 13.7 years), CCF acuity score (13.3 +/- 3.9), APACHE II score (28.7 +/- 4.7). MAP (VNA: 82.8 +/- 16.9; FNA: 86.2 +/- 18.9 mmHg), CO, cardiac index, pressor support interventions required (VNA: 16%: FNA: 48.4%, P < 0.001), blood volume changes (Critline) (VNA: -6.6 +/- 5.2; FNA: -7.59 +/- 6.7, P < 0.05), S. albumin (VNA: 2.4 +/- 0.6; FNA: 2.81 +/- 0.9 g/dl, ns) pre/post S.Na (VNA: 138.7 +/- 5.1/141.7 +/- 2.3; FNA: 136.6 +/- 5.96/139.1 +/- 3.71 mmol/dl), osmolality, Urea (VNA: 69.5 +/- 0.6; FNA: 70.5 +/- 0.6%, ns) and Creatinine (VNA: 56.6 +/- 0.5: FNA: 59.6 +/- 0.5%, ns) Reduction ratio, dialysis time (VNA: 4.8 +/- 0.5: FNA: 4.6 +/- 0.45 h) and achieved UF (VNA: 2.0 +/- 1.2; FNA: 1.56 +/- 1.3 L, P < 0.05) were measured. CONCLUSION: Haemodynamic stability was greater during Protocol B than during Protocol A in all patients. Significantly less intervention was noted during Protocol B, despite the same dialysis delivery during both Protocols. Relative Blood volume changes were less during Protocol B, despite a greater total ultrafiltration. Variable sodium dialysate coupled with a variable ultrafiltration rate seems to be the preferred dialysis prescription for ICU ARF patients undergoing intermittent haemodialysis.

Acute Kidney Injury↗
PubMed1996

Involvement of prostaglandins and 5-hydroxytryptamine in the contractile effect of platelet-activating factor in rat isolated gastric corpus.

The present study characterizes the nature of the response to the platelet-activating factor (PAF) in isolated gastric corpus with and without mucosa. PAF (10(-8) M) induced contraction of rat isolated gastric corpus strips followed by desensitization of this tissue. Incubation of strips with the specific PAF-receptor antagonist WEB 2086 (5 x 10(-8) -5 x 10(-5) M) the prostaglandin blocker indomethacin (10(-6) M) and the 5-hydroxytryptamine antagonist methysergide (10(-5) M) reduced significantly the contraction induced by PAF. Neither of the histamine H1/H2 antagonists diphenhydramine (10(-6) M) or cimetidine (10(-5) M) affected the contraction induced by PAF. In contrast with the whole gastric corpus, in mucosa-free strips, the contractile effect of PAF was not modified by methysergide. The present study supports the view that the effect of PAF is mediated by activation of specific PAF receptors and the release of prostaglandins and 5-hydroxytryptamine in isolated gastric corpus. Furthermore, our results suggest a role of the gastric mucosa via the release of 5-hydroxytryptamine which contributes to the contractile effect of PAF in the gastric smooth muscle.

Acetylcholine↗
PubMed1996

Concentration-time profiles of oxytetracycline in blood, kidney and liver of tench (Tinca tinca L) after intramuscular administration.

Oxytetracycline (OTC) is a widely-used antibiotic in several animal species. The Food and Drug Administration allows OTC to be used in fish intended for human food, but there is limited kinetics data available. We studied OTC concentrations in plasma, kidney and liver in tenches (Tinca tinca L) after im administration using HPLC. Concentrations were fit to a monocompartment open model by extended least squares regression analysis using the MULTI (ELS) computer program. Peaks of OTC concentrations (Cmax) occurred at 4 h for blood and kidney and 72 h for liver and were 134.1 micrograms/mL, 129.8 micrograms/g and 333.4 micrograms/g, respectively. There was a high correlation (r = 0.9448) between blood and kidney concentrations and less between blood and liver. Concentrations were statistically different for each system. The blood OTC concentrations were higher than renal concentrations 92% of the time and were higher than hepatic concentrations 29% of the time. The plasma OTC half-life (21.2 h) was longer than in homeothermic species. The tench liver maintains considerable OTC residues and may affect food products derived from that organ.

Animals↗
PubMed1995

Nitric oxide and sensory afferent neurones modulate the protective effects of low-dose endotoxin on rat gastric mucosal damage.

Pretreatment (1 h) with low doses (5-40 micrograms/kg i.p.) of Escherichia coli endotoxin dose dependently reduced the gastric mucosal damage induced by a 10 min challenge with 1 ml ethanol (50% and 100%) in conscious rats. Treatment with the nitric oxide synthesis inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 5 and 10 mg/kg i.p.), significantly inhibited the protective effects of endotoxin (40 micrograms/kg i.p.). The actions of L-NAME were reversed by the prior administration of L-arginine (100 mg/kg i.p.). The protective effects of endotoxin were not influenced by pretreatment with dexamethasone (5 mg/kg s.c. twice) or indomethacin (5 mg/kg s.c.). However, ablation of sensory afferent neurons by capsaicin pretreatment (20, 30 and 50 mg/kg s.c.) abolished the mucosa protective effects of endotoxin (40 micrograms/kg). These findings suggest that the protection elicited by low doses of endotoxin against ethanol-induced mucosal damage involves synthesis of nitric oxide and activation of sensory neurones.

Analysis of Variance↗