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Biomedical subjects

J López

Publications and source records attributed to J López.

At least 73 records · Page 4Linked to original sources
PubMed1999

Definition of nonvolatile markers for flavor of tomato (Lycopersicon esculentum mill.) as tools in selection and breeding.

A methodology for flavor and composition assessment of processed tomato juice samples was developed using a wide range of commercial processing tomato varieties (Lycopersicon esculentum) grown in Spain and the United States. Fruitiness intensity was found by a trained panel to best describe overall tomato flavor. For two consecutive years, fruitiness intensity was significantly dependent on growing location and variety, and it was consistently linked to increased levels of glucose and reducing sugars and decreased glutamic acid content. Using the same procedure on a population of 176 breeding lines derived from the wild species of Lycopersicon pimpinellifolium, it was shown that tomato fruitiness intensity was significantly correlated to reducing sugars/glutamic acid ratio and glucose and glutamic acid contents. The definition of markers for tomato flavor of processed juice can provide the tomato breeder and processor with reliable analytical tools that can be applied in a straightforward way for the identification of raw materials that can be processed into juice with predictably high or low fruitiness.

Beverages↗
PubMed1999

Administration of recombinant human granulocyte colony-stimulating factor to normal donors: results of the Spanish National Donor Registry. Spanish Group of Allo-PBT.

A Spanish National PBPC Donor Registry has recently been established for short- and long-term safety data collection in normal donors receiving rhG-CSF. To date, 466 donors have been included in the Registry. Median (range) dose and duration of rhG-CSF administration was 10 microg/kg/day (4-20) and 5 days (4-8), respectively. Donors underwent a median of two aphereses (range, 1-5). Adverse effects consisted mainly of bone pain (90.2%), headache (16.9%) and fever (6. 1%), but no donor discontinued rhG-CSF prematurely due to toxicity. Side-effects were more frequent in donors receiving >10 microg/kg/day than in those with lower doses (82.8% vs 61.8%; P = 0. 004). A significant decrease between baseline and post-apheresis platelet counts was the most important analytical finding (229 x 10(9)/l vs 140 x 10(9)/l; P < 0.0001), with a progressive reduction in platelet count with each apheresis procedure. One donor developed pneumothorax that required hospitalization due to central venous line placement. The mean CD34+ cell dose collected was 6.9 x 10(6)/kg (range, 1.3-36), with only 14 donors (2.9%) not achieving a minimum target of CD34+ cells of 2 x 10(6)/kg. No definitive information about potential long-term side effects is yet available. However, we hope this National Registry will serve as a useful basis for better monitoring of the efficiency and side-effects of cytokine administration in healthy people.

Adolescent↗
PubMed1999

Relationship of plasma leptin to plasma cytokines and human survivalin sepsis and septic shock.

Leptin production is increased in rodents by administration of endotoxin or cytokines. To investigate whether circulating leptin is related to cytokine release and survival in human sepsis, plasma concentrations of leptin, interleukin (IL)-6, IL-1beta, tumor necrosis factor (TNF)-alpha, soluble TNF receptor type I, IL-1 receptor antagonist (IL-1ra), and the inflammatory modulator IL-10 were measured as soon as severe sepsis (n=28) or septic shock (n=14) developed and every 6 h for 24 h. Patients with sepsis or septic shock had leptin concentrations 2.3- and 4.2-fold greater, respectively, than the control group. There was an independent association for leptin with IL-1ra and IL-10 in both patient groups. By discriminant analysis, leptin and IL-6 were independent predictors of death. These findings suggest that increases in leptin levels may be a host defense mechanism during sepsis.

Analysis of Variance↗
PubMed1999

Vascular access for haemodialysis--an epidemiological study of the Catalan Renal Registry.

BACKGROUND: Vascular access (VA) continues to cause problems in a proportion of haemodialysis (HD) patients. VA complications are a major cause of hospitalization, with the resulting financial consequences and human suffering. The purpose of the study was to assess the types and duration of function of different modalities of VA in Catalunya and to relate them to treatment characteristics, to study the characteristics of patients who necessitated more than four VAs and to describe the factors associated with the start of HD using a catheter. METHODS: The Catalan Renal Registry, using a questionnaire, sampled the data of all patients alive on December 31, 1997 (n=3073). Data were analysed using the chi2 test, ANOVA and logistic regression. RESULTS: In 85.8% of HD patients in Catalunya, an AV fistula was used, in 8.5% a vascular graft and in 5.6% a catheter. In 48% of incident HD patients in 1997, a catheter was necessary due to lack of an AV fistula. The use of grafts increases with progressive time on dialysis, reaching > 10% amongst patients on dialysis for >7 years. The average time of function for AV fistula was 4 years, for grafts 2 years and for catheters 9 months. A total of 39.1% of patients required only one VA during the entire time on HD, 29.9% two, 14.4% three, and 16.5% four or more. The duration of VA function decreases with age. In patients with autosomal dominant polycystic kidney disease and glomerulonephritis, the duration of VA function exceeds 4 years; it is 3 years in patients with vascular disease and 25 months in diabetic patients. CONCLUSIONS: The most frequent modality of VA used in Catalunya is the AV fistula. It is used more frequently in male than in female patients. Approximately half of the patients have no VA at the time of start of renal replacement therapy. Age, duration of dialysis treatment and diabetes have an adverse effect on the duration of VA function. Repeated VA failure concerns a minority of patients.

Adolescent↗
PubMed1999

[A universal method to correct underreporting of communicable diseases. Real incidence of hydatidosis in Chile, 1985-1994].

BACKGROUND: There is evidence to postulate that undernotification is the reason for the great decrease in the reported incidence of hydatidosis in Chile. AIM: To develop and propose a method to assess the notification of transmissible diseases, based on observed lethality and hospital discharges. MATERIAL AND METHODS: Human hydatidosis in the period 1985-1994 was used as a model to develop the method. Official reports and mortality were analyzed first, determining the first lethality rate. A second lethality rate was calculated based on hospital discharges and a third, based on all Chilean surgical series published in the last two decades. Adjusting official notification of lethality to the true lethality according to surgical series, the number of unreported cases was calculated and the true incidence of hydatidosis was calculated, summing these cases to the official notification. RESULTS: According to this method, the real rates of human hydatidosis in the period 1985-1994, would fluctuate between 6.5 and 11.4 per 100,000. This figure is four times higher than the official notification in the analysed period. CONCLUSIONS: The correction of under notification based on hospital discharges, with or without correction for repeated hospital admissions, or real mortality of surgical series gave similar results, suggesting that both methods are correct.

Chile↗
PubMed1998

[Von Willebrand disease: characteristics and response to desmopressin. Study of 103 cases].

BACKGROUND: To describe the main characteristics and response to desmopressin infusion in 103 patients suffering from von Willebrand disease (vWD). PATIENTS AND METHODS: The criteria for diagnosis were (except for type 2N) the coexistence of von Willebrand factor ristocetin cofactor (vWF:RCo) activity < 50 U/dl with bleeding disease or one of the following data: von Willebrand factor antigen (vWF:Ag) activity < 50 U/dl, factor VIII (FVIII) activity < 50 U/dl or the existence of a increased bleeding time (BT). Multimeric studies of vWF were performed in 51 cases and ristocetin induced platelet aggregation (RIPA) was also performed. RESULTS: Spontaneous bleeding was found in 36 patients, while in 18 cases the diagnosis was done after surgical bleeding. Thirteen patients (6 presenting with mild bleeding) were studied for abnormalities in the routine preanestesic tests. Other 22 patients were diagnosed with vWD by familial studies. There were 3 patients with type 2B, 1 case with type 2N and other patient with type 3. BT was found increased in 26 out of 58 patients. The activities of vWF:CoR and vWF:Ag were 38.4 (9.4) U/dl and 45.8 (23.2) U/dl, respectively, while the activity of FVIII was 49.9 (20.8) U/dl. Prophylactic DDAVP (desmopressin) was infused in 32 patients. After 1 h, basal activities of vWF:CoR and vWF:Ag were increased by 3.1 (3.2) and 3.4 (3.1) times, respectively, and maintained for 3 h. FVIII activity increased 3.6 (2.3) times the basal levels decreasing after 3 h (2.9 [2.1]; p < 0.01). The BT was corrected in 8 out of ten patients. CONCLUSIONS: vWD is a major cause of surgical bleeding. Preanestesic anamnesis and coagulation tests can be useful to identify vWD. Many patients with vWD have normal BT. A failure in the response to desmopressin infusion is unusual.

Deamino Arginine Vasopressin↗
PubMed1998

In vivo response of mouse liver to gamma-radiation assessed by the comet assay.

The alkaline comet assay was used to measure DNA damage induced in liver cells of mice irradiated with gamma-radiation, as well as the repair competency of these cells. A simplified procedure for the isolation of nuclei from cells in solid tissues was developed. This simplified method allows nuclei to be processed into lysis only 5 min after briefly chilling the tissue to depress any enzymatic activity. The nuclei were spontaneously released by a sharp cut of the tissue and exposure of the cut to a drop of 50 mM sodium-phosphate buffer at pH 7.2, immediately before adding the low melting agarose. Thus, the procedure minimizes time-dependent modification of the endogenous level of damage by reducing additional strand breaks or repair produced during processing. The induction of DNA damage by gamma-radiation behaved as a one-hit event in the liver cells, as there was a positive linear correlation between the radiation dose and the fraction of DNA migrated into the comet tails. The level of DNA damage produced by gamma-radiation was highly significant at doses of 0.5 and 1 Gy. Based on the mean extent of DNA migration, the level of damage was not reduced following only one hour of repair time however, after two hours, there was a significant reduction in DNA migration. To increase the resolution of the statistical analysis, the nuclei of each sample were distributed in five types of comets, according to the percentage of DNA in the tail. To compare the frequency distributions of these types of comets between different experimental situations, a Pearson chi-square statistical analysis was applied. It was found, by this analysis, that the DNA repair which occurred 1 h after 1 Gy of gamma-irradiation is significant and that, after 2 h, more DNA repair occurs, but a significant residual damage still persists when comparing this sample with the control.

Animals↗
PubMed1998

Inertia and Resilience in the Responses of the Aquatic Bryophyte Fontinalis antipyretica Hedw. to Thermal Stress

The physiological responses of the aquatic bryophyte Fontinalis antipyretica Hedw. to high temperatures, ranging from 16 degreesC (control) to 34 degreesC, were investigated experimentally. Plant samples were maintained at the temperature under study for up to 25 days with regular determination of physiological variables (pigment ratio and photosynthetic and respiratory rates). Physiological responses to temperature did not differ significantly between mosses collected from a normal river site and from a river site with abnormally high temperature due to input from a hot spring. Simple curve-fitting procedures and summary statistics analogous to those used in toxicological research were employed to compare responses as revealed by the different physiological variables. In a second series of experiments, the capacity of F. antipyretica to recover from high-temperature stress was investigated by maintaining samples at 30 degreesC for 2, 4, or 10 days, then transferring the samples to normal conditions (16 degreesC) for 40 days. Physiological variables were again monitored at regular intervals throughout both phases of the experiment. In general, good recovery was observed even after exposure to high temperatures for 10 days. The results of these assays allow quantification of the relationship between a pigment ratio and net photosynthesis rate.

Journal Article↗
PubMed1998

Internal thoracic artery atherosclerosis after coarctation repair in an adult.

We report a rare case of a patient with an unsuitable grossly atherosclerotic and extensively calcified right internal thoracic artery found during a coronary bypass grafting operation. He had undergone an aortic coarctation repair 35 years before, with long-term systemic hypertension previous to the operation and sustained after it. It is advisable to be alert to the possibility of atherosclerotic degeneration of the internal thoracic artery in these patients.

Aortic Coarctation↗
PubMed1998

[Patent foramen ovale as a cause of recurrent cerebral embolism. Closure with minimally invasive surgery].

We report a clinical case of a 63-year-old patient, referred with a history of repeated strokes, whose only cause was a patent foramen ovale with shunt right to left diagnosed by transesophageal echocardiography. He underwent minimally invasive surgery, through right parasternal minithoracotomy, practising defect closure. We comment on the value of echocardiography for diagnosing this pathology and the utility of this surgical technique for repairing these defects.

Cardiac Surgical Procedures↗
PubMed1998

HIV prevalence and risk behaviors among patients attending Los Angeles County Tuberculosis Clinics: 1993-1996.

PURPOSE: This study aimed to describe prevalence of and risk factors for HIV among persons with newly diagnosed class III (confirmed) and class V (suspected) cases of tuberculosis (TB) patients in Los Angeles County. METHODS: HIV testing was performed on 1307 blood specimens after routine tests were completed at six TB clinics in Los Angeles County. HIV test results were matched to demographic and risk behavior information by use of an unlinked study methodology. RESULTS: The overall HIV prevalence rate was 10.8%. By demographic characteristics, the highest prevalence rates were observed among persons born in the United States (15.7%), males (14.1%), blacks (14.3%), and those aged 30-44 years (14.4%). Confirmed TB cases (14%) were more likely to be HIV-infected than were suspect cases (9.6%). Risk behaviors associated with positive HIV serostatus included the injection of nonprescription drugs, having sex with an injection drug user, and use of noninjection forms of heroin, cocaine, and tranquilizers. Men who have sex with men were more likely to be HIV-infected than were heterosexual males. CONCLUSIONS: HIV testing and counseling should be a standard of care in TB clinics. The observed high HIV prevalence rate reinforces the importance of designing prevention strategies that specifically target patients with TB.

Adolescent↗
PubMed1998

Can we use 99mTc-MIBI in functional studies of the parathyroid gland?

The usefulness of technetium-99m-sestamibi (99mTc-MIBI) in patients with secondary hyperparathyroidism on haemodialysis was assessed. We studied 33 patients with parathyroid scintigraphy with i.v. (99mTc-MIBI). Static images in a scintillation camera were taken at 15 and 120 min after the injection. With P x Ca<80, we performed an inhibition test with calcitriol i.v. 2 microg, three times a week, for 2 weeks. The MIBI study and assessment of intact parathyroid hormone (iPTH) were performed before (baseline study) and after inhibition. A 'focal positive study' corresponded to one or more areas of abnormal hypercaptation in relation to surrounding thyroid tissue seen in early images and persisting in later images, and a 'negative study' did not correspond to the previous image. In the baseline study, iPTH in the positive MIBI group was significantly greater than in the negative group. Eight positive MIBI patients had a bone biopsy; six corresponded to severe osteitis fibrosa and two to mild osteitis fibrosa. In the negative MIBI group, four of the six patients who had bone biopsy had mild forms of osteitis fibrosa (Fisher=0.03); the other two had low turnover forms. A positive inhibition test was defined when the basal uptake disappeared after calcitriol administration. In these patients, we observed a significant decrease of iPTH, not observed in the negative inhibition test. In 10 patients who had been parathyroidectomized, those with alpha positive basal MIBI result had a nodular parathyroid hyperplasia. We conclude that a scintigraphic parathyroid study with 99mTc-MIBI showed a good correlation with functional parathyroid status. With the same inhibition test, only some glands were inhibited, suggesting that this could be the expression of different vitamin D receptor densities in inhibited glands and/or a different kind of proliferation in those glands. This test would be of value in functional studies when a therapeutic decision must be made.

Adult↗
PubMed1998

Immunohistochemical detection of Brucella abortus antigens in tissues from aborted bovine fetuses using a commercially available polyclonal antibody.

A commercially available polyclonal antibody and an avidin-biotin-peroxidase immunohistochemical technique were used to detect Brucella abortus antigens in formalin-fixed, paraffin-embedded tissues of lung and liver from 20 aborted bovine fetuses. Thirteen fetuses were obtained from farms with a previous history of brucellosis, and 7 were collected from farms without a history of brucellosis. Among the 13 aborted bovine fetuses obtained from farms with a history of brucellosis, immunoreactivity to B. abortus was detected in lung (9 fetuses) and in liver (1 fetus), whereas Brucella was cultured from abomasal contents in 9 fetuses (8 were immunohistochemically positive). In addition, 11 dams of these 13 aborted bovine fetuses had antibodies to Brucella. Brucella abortus was not detected by immunohistochemistry in the 7 aborted bovine fetuses collected from farms without a history of brucellosis. Bacteriologic culture and serologic tests were also negative for Brucella. The results of this study revealed that the immunohistochemical technique was sufficiently sensitive for detecting B. abortus antigens in formalin-fixed lung tissues from naturally aborted bovine fetuses. Although additional studies are necessary to rule out cross-reaction of the polyclonal antibody with other microorganisms that cause bovine abortion, this immunohistochemical technique could be a complementary tool to serology and bacteriology for the diagnosis of brucellosis.

Abortion, Veterinary↗
PubMed1998

Role of interferon alfa-2b in the induction and maintenance treatment of low-grade non-Hodgkin's lymphoma: results from a prospective, multicenter trial with double randomization.

PURPOSE: To evaluate the effectiveness of adding interferon (IFN) alfa-2b to chemotherapy in the induction treatment of low-grade non-Hodgkin's lymphoma (NHL), and to assess the role of maintenance IFN. PATIENTS AND METHODS: A multicenter, two-phase controlled trial with double randomization was conducted in 155 patients with low-grade NHL. In the first randomization, 78 patients received cyclophosphamide, vincristine, and prednisone (CVP) and IFN, 3 MU/m2 three times a week for 3 months, and 77 patients received CVP alone. Responding patients were randomized to receive IFN for 1 year versus observation. RESULTS: Of 144 assessable patients, 73 received CVP + IFN and 71 received CVP. Responses were similar: CVP + IFN 79% versus CVP 76% (P = .62). The number of patients who did not complete the treatment was higher in the CVP + IFN group than in the CVP group (18% v 4%; P = .009), although the received dose-intensity of chemotherapy was comparable. Duration of response and progression-free survival (PFS) were significantly higher in the CVP + IFN group than in the CVP group (P = .0004). However, we observed no differences in overall survival (OS) (P = .30), with a median follow-up for the surviving patients of 3 years. Grade 3/4 granulocytopenia was the most frequent toxicity and was similar in both groups (33% v32%). Eighty-three (74%) of the 112 responding patients were randomized to maintenance IFN or observation. The duration of response was similar between 42 patients that received IFN compared with 41 control patients (P = .83), independently of treatment previously administered. CONCLUSION: Adding IFN alfa-2b to induction CVP in low-grade NHL did not induce a higher response rate, but it significantly increased the duration of the responses. We found significant differences in PFS that favored the patients who received CVP + IFN, but not in OS. To date, no additional benefit has been seen from the administration of IFN for maintenance.

Adult↗
PubMed1998

Prospective application of risk scores in the interhospital transport of patients.

We carried out a prospective evaluation of 172 patients using our own risk score for patients transferred from the emergency department of a community hospital in Tudela, Spain, to main centres, during 1988. Although the data go back almost 10 years, this scoring has not been internationally published and is at present widely applied in Spain. Patients scoring less than 7 points were transferred under specialized nursing supervision (Group I), and those scoring equal to or over 7 points were transferred in a specially equipped intensive care unit surface ambulance and supervised by a physician and a nurse (Group II). There were 102 patients in Group I and 70 in Group II. Complications arising during transfer were defined as minor or serious. A low overall incidence of complications was recorded--a total of 29 cases (16.9% of all transfers). The incidence of complications was significantly higher in Group II patients (p < 0.005). One patient from Group II died during transport. All patients from Group II were admitted to the ICUs compared with only 20 (18.6%) from Group I (p < 0.001). Of a total of 23 deaths in hospital, nine were from Group I and 14 from Group II. During the first 24 hours after admission, six patients died from Group II and none from Group I. The application of risk scores has permitted to assign effectively technical and human resources for a safe interhospital transfer of critically ill patients.

Ambulances↗