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Biomedical subjects

R Lozano

Publications and source records attributed to R Lozano.

At least 37 records · Page 2Linked to original sources
PubMed1999

Hepatic lesion ablation with bipolar saline-enhanced radiofrequency in the audible spectrum.

RATIONALE AND OBJECTIVES: The authors' purpose was to create larger and more regular liver lesions in vitro by testing a new hyperthermia approach that uses a bipolar saline-enhanced electrode for radiofrequency (RF) in the audible spectrum and a greater power supply. MATERIALS AND METHODS: The authors' hyperthermia approach (group A, n = 23) was used in excised porcine livers, and the results were compared with those of a previously described monopolar saline-enhanced electrode procedure (group B, n = 23). In each set of experiments, RF in the audible spectrum current (50 Hz) was provided for 15 minutes with a similar ablation protocol. Electrical variables (impedance, current, voltage, power, and energy), temperatures in the lesions, volume size, regularity ratio of the lesion, and microscopic findings were measured. RESULTS: In group A, the mean volume size and the mean regularity ratio values were 144.8 cm3 +/- 59.8 and 0.78 +/- 0.1, respectively. In group B, the mean volume size and regularity ratio values were 62.1 cm3 +/- 36.4 and 0.62 +/- 0.1, respectively. The values in group B were thus significantly lower than those in group A (P < .01). The lesions in group A were also more homogeneous. No significant differences were found in electrical variables. CONCLUSION: The new bipolar saline-enhanced electrode produced larger, more regular, and more homogeneous lesions ex vivo than the previously used monopolar saline-enhanced electrode method. Using a greater power supply increased the amount of coagulative necrosis.

Animals↗
PubMed1999

Measuring health-related quality of life in patients with mild to moderate eczema and psoriasis: clinical validity, reliability and sensitivity to change of the DLQI. The Cavide Research Group.

The aim of this study was to assess the feasibility, validity, reliability and sensitivity to change of a Spanish version of the Dermatology Life Quality Index (DLQI) in patients with mild to moderate eczema and psoriasis who were treated with topical corticosteroids. The final study sample comprised 237 patients (48% eczema). Discriminant validity was tested by comparing patients' scores with those of a random sample of the general population (n = 100), and convergent validity by analysing correlations between DLQI scores, measures of clinical severity, and domain scores on the Nottingham Health Profile (NHP). Internal consistency and test-retest reliability were tested in clinically stable patients (n = 94), and responsiveness in a clinically unstable group (n = 143) initiating treatment with topical corticosteroids. Patient scores were significantly higher than general population scores (4.3 vs. 0. 27, P < 0.001). Correlations with NHP domains ranged from 0.12 to 0. 32, and there was significant correlation with clinical measures (r = 0.26, P < 0.001). Reliability was good (Cronbach's alpha = 0.83; intraclass correlation coefficient = 0.88), and the instrument proved responsive to change (effect size for the total group of de novo patients = 0.70), though the great majority of changes occurred in items 1 and 2. The NHP Emotional Reactions and Mobility domains were more responsive than some DLQI domains. In clinical trials of treatments for mild to moderate eczema and psoriasis, it is likely that only items 1 and 2 of the DLQI will be needed, and it is probably advisable to include generic instruments alongside the DLQI.

Administration, Topical↗
PubMed1999

FALSIFLORA, the tomato orthologue of FLORICAULA and LEAFY, controls flowering time and floral meristem identity.

Characterization of the tomato falsiflora mutant shows that fa mutation mainly alters the development of the inflorescence resulting in the replacement of flowers by secondary shoots, but also produces a late-flowering phenotype with an increased number of leaves below first and successive inflorescences. This pattern suggests that the FALSIFLORA (FA) locus regulates both floral meristem identity and flowering time in tomato in a similar way to the floral identity genes FLORICAULA (FLO) of Antirrhinum and LEAFY (LFY) of Arabidopsis. To analyse whether the fa phenotype is the result of a mutation in the tomato FLO/LFY gene, we have cloned and analysed the tomato FLO/LFY homologue (TOFL) in both wild-type and fa plants following a candidate gene strategy. The wild-type gene is predicted to encode a protein sharing 90% identity with NFL1 and ALF, the FLO/LFY-like proteins in Nicotiana and Petunia, and about 80 and 70% identity with either FLO or LFY. In the fa mutant, however, the gene showed a 16 bp deletion that results in a frameshift mutation and in a truncated protein. The co-segregation of this deletion with the fa phenotype in a total of 240 F2 plants analysed supports the idea that FA is the tomato orthologue to FLO and LFY. The gene is expressed in both vegetative and floral meristems, in leaf primordia and leaves, and in the four floral organs. The function of this gene in comparison with other FLO/LFY orthologues is analysed in tomato, a plant with a sympodial growth habit and a cymose inflorescence development.

Amino Acid Sequence↗
PubMed1999

Durable clinical and pathologic response of hepatocellular carcinoma to systemic and hepatic arterial administration of platinol, recombinant interferon alpha 2B, doxorubicin, and 5-fluorouracil: a communication.

The case described here illustrates the antitumor activity of a four-drug systemic combination chemobiotherapy with platinol, recombinant interferon alpha 2b, doxorubicin (Adriamycin), and 5-fluorouracil (5-FU) (PIAF) in a patient with diffuse hepatocellular carcinoma involving the liver and lungs.

Aged↗
PubMed1999

Citicoline protects hippocampal neurons against apoptosis induced by brain beta-amyloid deposits plus cerebral hypoperfusion in rats.

Citicoline is an endogenous intermediate involved in the biosynthesis of brain phospholipids and acetylcholine which has been extensively used for the treatment of several neurodegenerative conditions. The effects of citicoline on neurodegeneration, apoptosis and learning were investigated in male Sprague Dawley rats subjected to implants of the beta-amyloid fragment 1-40 (A beta 4: 3 Mmol) into the right hippocampus and to permanent unilateral occlusion of the carotid artery. Citicoline (CDP; 0, 62.5, 125 and 250 mg/kg/day i.p.) was given during 2 days before and for 5 days after surgery, and the extension of the degeneration and the number of apoptotic figures (TUNEL technique) were evaluated in the dentate gyrus (DG) and the CA1 area of the hippocampus. Citicoline, at 125 and 250 mg/kg, reduced the number of apoptotic neurons in the hippocampus of rats with A beta 4/hypoperfusion-induced neurodegeneration (CDP0 = 105.3 +/- 32.8 apoptotic figures; CDP125 = 39.2 +/- 7.4** apoptotic figures; CDP250 = 34.5 +/- 14.4** apoptotic figures; **p < 0.01 vs. CDP0). CDP also reduced neuronal degeneration in the CA1 area in a dose-dependent manner (CDP0 = 450.5 +/- 130.1 microns; CDP62.5 = 280.6 +/- 76.3 microns; CDP125 = 86.6 +/- 37.3* microns; CDP250 = 121.7 +/- 85.3* microns; p < 0.05 vs. CDP0). Variability of results was very high in the DG, where a significant reduction in the extent of neurodegeneration was only observed in the group of rats receiving 62.5 mg/kg of citicoline. Finally, citicoline improved retention of a passive avoidance learning task, increasing the number of avoidances (Av) (CDP0 = 4.2 +/- 0.7 Av; CDP62.5 = 6.9 +/- 1.0 Av; CDP125 = 7.9 +/- 0.7** Av; CDP250 = 8.5 +/- 0.6** Av; **p < 0.01 vs. CDP0) in a dose-related manner. Based on these results, it was concluded that citicoline exerts antiapoptotic, neuroprotective and antiamnesic effects in conditions of neurodegeneration induced by A beta 4 plus hypoperfusion.

Amyloid beta-Peptides↗
PubMed1999

Double-blind placebo-controlled study with citicoline in APOE genotyped Alzheimer's disease patients. Effects on cognitive performance, brain bioelectrical activity and cerebral perfusion.

Cytidine 5'-diphosphocholine (citicoline) is a an endogenous intermediate in the biosynthesis of structural membrane phospholipids and brain acetylcholine. Citicoline has been extensively used for the treatment of neurodegenerative disorders associated with head trauma, stroke, brain aging, cerebrovascular pathology and Alzheimer's disease. In this study we have investigated the efficacy and safety of the treatment with citicoline versus placebo in patients with Alzheimer disease. Thirty patients (age = 73.0 +/- 8.5 years; range = 57-87 years) with mild to moderate senile dementia (GDS: stages 3-6) of the Alzheimer type were included in a double-blind, randomized and placebo-controlled clinical trial. After a 2-week period of drug washout, patients were treated with i) placebo (n = 17; age = 73 +/- 5 years) or ii) 1,000 mg/day of citicoline (n = 13; age = 76 +/- 9 years) for 12 weeks (84 days). Examinations were done at baseline (T0) and after the 12 weeks of treatment (T12). As compared to placebo, citicoline improved cognitive performance in Alzheimer's disease patients with APOE E4 (ADAS: difference between groups = -3.2 +/- 1.8 scores, p < 0.05; ADAS-cog: difference between groups = -2.3 +/- 1.5, ns); and this improvement on cognition was more pronounced (ADAS, p < 0.01; ADAS-cog: difference between groups = -2.8 +/- 1.3, p < 0.06) in patients with mild dementia (GDS < 5). Citicoline also increased cerebral blood flow velocities in comparison with placebo (p < 0.05) when transcranial Doppler recordings from both hemispheres were considered together, as well as diastolic velocity in the left middle cerebral artery (p < 0.05). Patients treated with citicoline showed an increase in the percentage of brain bioelectrical activity of alpha (occipital electrodes) and theta type (left side electrodes), accompanied by a decrease in relative delta activity particularly marked in the left temporal lobe. Significant differences with respect to placebo (p < 0.05) were observed for theta activity in several fronto-parieto-temporal electrodes of the left hemisphere. Treatment with citicoline tended to reduce serum IL-1 beta levels, mainly after 4 weeks of administration, with no modified blood histamine content. In addition, neither adverse side effects nor alterations in biological and hematological parameters were induced by citicoline. The present data indicate that citicoline (1,000 mg/day) is well tolerated and improves cognitive performance, cerebral blood perfusion and the brain bioelectrical activity pattern in AD patients. According to our results, it seems that citicoline might be a useful treatment in Alzheimer's disease, and that the efficacy of this compound is greater in patients with mild mental deterioration and/or bearing the epsilon 4 allele of the APOE.

Aged↗
PubMed1999

Primary hydatid disease in lumbar muscles.

The authors report a case of primary hydatid disease in the lumbar muscles of a 40-year-old male patient. The rarity of this disease in our regions and the low incidence of this location make primary diagnosis difficult. The tumor had been treated elsewhere five years previously by means of simple excision. Recurrence of the lesion was diagnosed five years after the first surgery. Wide excision of the cyst and pericyst with a 3.5-cm security margin was performed. Six years after the last surgery, no recurrence has been detected.

Adult↗
PubMed1998

Immune response and cytokines in septic rats undergoing blood transfusion.

BACKGROUND: Intrabdominal sepsis and allogeneic blood transfusion have been associated with a depression of the immune response in patients undergoing surgery. Some authors have considered that an already immunocompromised host is probably primed for a potential detrimental effect of allogeneic blood. The aim of this paper is to ascertain the effects of allogeneic blood transfusion on the lymphocyte subsets and cytokines in septic rats. MATERIALS AND METHODS: Thirty rats were allotted into three groups: Sham-CLP, anesthesia and laparotomy; CLP, cecal ligation and puncture; CLP+BT, CLP and allogeneic blood transfusion. Preoperatively and on the 1st, 3rd, and 7th postoperative days, the cell percentages of lymphocyte subpopulations, the IL-2 receptor expression, and the IL-1, IL-2, TNF-alpha and IFN-gamma were measured in blood by flow cytometry and ELISA: RESULTS: CLP+BT rats showed on Day 3 a decrease of the CD4+%, an increase of the IL-2R expression directly correlated to the increase of the CD8+% phenotype, a steady increase of IL-1 levels, a decrease of the TNF-alpha levels on the 1st and 3rd days, and a decrease of the IL-2 and IFN-gamma on Day 1. CONCLUSIONS: An accumulative effect of the immunodepression induced by sepsis was observed when allogeneic blood transfusion is added. Blood transfusion + sepsis induces an extensive impairment on cellular immune response and an initial cytokine downregulation, except for IL-1.

Animals↗
PubMed1998

Tomato flower abnormalities induced by low temperatures are associated with changes of expression of MADS-Box genes

Flower and fruit development in tomato (Lycopersicon esculentum Mill. ) were severely affected when plants were grown at low temperatures, displaying homeotic and meristic transformations and alterations in the fusion pattern of the organs. Most of these homeotic transformations modified the identity of stamens and carpels, giving rise to intermediate organs. Complete homeotic transformations were rarely found and always affected organs of the reproductive whorls. Meristic transformations were also commonly observed in the reproductive whorls, which developed with an excessive number of organs. Scanning electron microscopy revealed that meristic transformations take place very early in the development of the flower and are related to a significant increase in the floral meristem size. However, homeotic transformations should occur later during the development of the organ primordia. Steady-state levels of transcripts corresponding to tomato MADS-box genes TM4, TM5, TM6, and TAG1 were greatly increased by low temperatures and could be related to these flower abnormalities. Moreover, in situ hybridization analyses showed that low temperatures also altered the stage-specific expression of TM4.

Journal Article↗
PubMed1998

A method to select an instrument for measurement of HR-QOL for cross-cultural adaptation applied to dermatology.

OBJECTIVE: The objective of this study was to develop a process to obtain an instrument to measure dermatology specific health-related quality of life (HR-QOL), and to adapt it into another culture, namely the Spanish-speaking community. DESIGN AND SETTING: By consensus, a multi-disciplinary team determined the qualities of an 'ideal' questionnaire as follows: need (absence of any such instrument), utility, multi-dimensionality, psychometric development, simplicity, high degree of standardisation, and accessibility. A bibliographic search was conducted on Medline, EMBASE and IME (Spanish Medical Index), using 'dermatology' and 'quality of life' as the key words, from January 1990 through to September 1997, supplemented by a second level reference search, to identify the instruments already in existence. Rather than develop a questionnaire ex novo, it was decided to make a cultural adaptation of an existing one. The questionnaires identified in the literature search were classified according to their generic or specific scope and it was decided to adapt a dermatology specific instrument. To select and compare the instruments, a model was developed which would provide an Adaptation Index (ADAPT), which includes the degree of development of psychometric properties, the formal design and the degree of standardisation at a given moment in time. RESULTS: Six dermatology specific scales were identified: Impact of Skin Disease Scale (IMPACT), Dermatology Life Quality Index (DLQI), Skindex, Dermatology Quality-of-Life Scales (DQOLS), Dermatology Specific Quality of Life (DSQL) and Qualita di Vita Italiana in Dermatologia (QUAVIDERM). The ADAPT Index for each of the above was determined at the time of the study and the DLQI was chosen for adaptation (ADAPT = 77, October 1997). CONCLUSIONS: The study showed the utility of ADAPT Index to assist in the selection process of the questionnaire to adapt. The results of the analysis indicate that in order to introduce and systematically use dermatology specific HR-QOL instruments, the indices require consolidation and improvement. There is a special need for an effort to be made in developing transculturally equivalent instruments suitable for international research.

Cross-Cultural Comparison↗
PubMed1997

Initial results of a new procedure for treatment of malignant obstruction of the left colon.

PURPOSE: This study was undertaken to analyze the results obtained in 38 unselected patients using a new and original procedure for treatment of malignant obstructions of the left colon. METHOD: This procedure involves three phases: 1) resolution of the obstruction by means of a stent placed at the site of the tumor; 2) recovery of the general state of the patient, study of the extent of disease, and mechanical preparation of the colon; 3) regulated and final surgery (if this is not suitable, the stent may be used as definitive palliative treatment). RESULTS: In 35 patients (92 percent), the obstruction was resolved with the stent. In 22 patients the three phases were completed, and in 13 patients the stent constituted definitive palliative treatment. Only one patient (2.6 percent) died after resection of the tumor. CONCLUSION: This procedure offers a new, safe, and efficacious option for treatment of neoplastic colorectal obstructions.

Adenocarcinoma↗
PubMed1997

Chronic atrophic gastritis: early diagnosis in a population where Helicobacter pylori infection is frequent.

Chronic atrophic gastritis (CAG) is a premalignant condition characterized by loss of gastric antral deep glands. The histologic changes in antral gastric biopsy specimens from 54 Peruvian patients with dyspepsia were studied to detail the development and characteristics of CAG. Ninety-six percent of the biopsies revealed severe superficial mucosal inflammation and 89% showed deep inflammation. Moderate or severe CAG was present in 36 (67%) of the 54 patients. In the early stages of CAG, a glandular lymphoid adherence lesion was noted in 17 (31%) of the 54 biopsy specimens. This lesion consisted of lymphocytes adherent to the antral deep gland cells and was associated with glandular epithelium alterations. The late stage was characterized by small glands, remnants of glands, and gland replacement with a fibrocellular infiltrate or intestinal metaplasia. We propose that the development of CAG probably proceeds via a stereotyped sequence, with an early deep inflammatory component that may trigger local gland destruction and eventual permanent loss.

Adolescent↗
PubMed1997

Phase II trial of hepatic arterial infusion of fluorouracil and recombinant human interferon alfa-2b for liver metastases of colorectal cancer refractory to systemic fluorouracil and leucovorin.

PURPOSE: To determine the toxicity, response rate, and survival in patients treated with hepatic arterial infusion (HAI) of fluorouracil (5-FU) plus recombinant human interferon alfa-2b (rIFN-alpha 2b) (Intron-A; Schering-Plough, Inc, Kenilworth, NJ) for colorectal carcinoma (CRC) liver metastases refractory to systemic 5-FU plus leucovorin (LCV). PATIENTS AND METHODS: Forty-eight patients were given a 6-hour HAI of rIFN-alpha 2b 5 MU/m2 followed by an 18-hour HAI of 5-FU, 1,500 mg/m2 daily for 5 days. Twenty-nine patients were treated through percutaneously placed catheters and 19 through implantable infusion pumps (Shiley Infusaid Inc, Noorwood, MA). Treatment cycles were repeated every 28 to 35 days. RESULTS: There were three (6.6%) complete remissions (CRs) and 12 (26.6%) partial remissions (PRs), for a CR plus PR rate of 33.3% among 45 assessable patients (95% confidence interval [CI], 20% to 49%). The median response duration was 7 months, while median survival duration was 15 months. Grade 3 to 4 treatment-related toxic effects included mucositis (40%), neutropenia (42%), and thrombocytopenia (12%). No hepatobiliary toxicity was encountered in any of the patients. Treatment was discontinued because of progressive liver disease in 23 patients and extrahepatic progression in 16, while six patients continue treatment through an infusaid pump. CONCLUSION: HAI of 5-FU plus rIFN-alpha 2b is well tolerated, devoid of hepatobiliary toxicity, and can produce a response rate of 33.3% among patients refractory to bolus intravenous (IV) 5-FU plus LCV. The lack of hepatobiliary toxicity may permit salvage HAI with floxuridine (FUDR) in patients whose liver tumors fail to respond to HAI of 5-FU plus rIFN-alpha 2b. Because diarrhea was not a common side effect of HAI of 5-FU plus rIFN-alpha 2b, it would be of interest to investigate whether alternating HAI of 5-FU and rIFN-alpha 2b with systemic irinotecan (CPT-11) will decrease the incidence of both hepatic and extrahepatic disease progression.

Adult↗
PubMed1997

Prednicarbate versus fluocortin for inflammatory dermatoses. A cost-effectiveness study.

The purpose of this study was to compare, from a societal perspective, the cost effectiveness of topical prednicarbate 0.25% and fluocortin 0.75% in the treatment of inflammatory dermatoses, such as dermatitis and eczema, in Spain. Effectiveness and tolerability were determined by means of a meta-analysis of 17 randomised double-blind controlled clinical trials, using a MEDLINE search and a second-level reference search. The data were obtained on the basis of a per-protocol assessment system, and the Mantel-Haenszel method (as modified by Peto) was used to make the statistical analysis. In terms of economic assessment, a model was developed in which the expected total cost was determined by the cost of the medicine (adjusted to the recommended dosage) plus the costs derived from the ineffectiveness and/or adverse effects associated with the different treatments. A sensitivity analysis was carried out on the basis of changes in: (i) clinical effectiveness; (ii) price of prednicarbate; (iii) incidence of adverse reactions; (iv) costs associated with ineffectiveness and/or adverse effects; and (v) the regimen under which prednicarbate was administered. The meta-analysis showed that there was a statistically significant difference between the 2 alternatives (p = 0.001). The value of a combined odds ratio [and 95% confidence interval (95% CI)] for the combined studies of prednicarbate was 1.54 (95% CI 1.10 to 2.15), compared with 0.73 (95% CI 0.60 to 0.89) for fluocortin relative to moderate or moderate-to-high potency corticosteroids. Effectiveness was 84.9% for prednicarbate and 69.7% for fluocortin, while frequency of adverse effects was 3.5% for prednicarbate and 4.9% for fluocortin. The total expected cost per patient treated was found to be 4600 Spanish pesetas (Pta) [$US37.10; 1996 values] for prednicarbate and Pta5778 ($US46.60; 1996 values) for fluocortin. The total expected cost per patient successfully treated was Pta5608 ($US45.20) for prednicarbate and Pta8680 ($US70) for fluocortin. Prednicarbate has been shown to have a favourable cost-effectiveness ratio, when compared with fluocortin, for the treatment of dermatitis and eczema in Spain. Additional pharmacoeconomic studies on topical corticosteroids are required, including the use of new variables, long term analysis and/or the measurements of the effect of the drug on patients' quality of life.

Administration, Topical↗
PubMed1997

A new method for quantifying the cognitive impairment. Its application in patients with vascular dementia.

Seven-three patients diagnosed with vascular dementia (VD) left to their natural evolution have been observed during a period of time of one year. The objective of this study is to find an index to quantify the degree of loss of cognitive capabilities in patients affected by VD, as well as to define the minimum loss of punctuation in this index, that can only be caused by an unfavourable evolution of the disease. This index, which we call Percentual Variation Index (PVI), is based on the evolution of the punctuations of the Cognoscitive Mini-Exam (CME) after a follow-up of one year. Our definition states that in order to consider patients as having cognitive impairment of vascular origin, they must lose more than 10% of their basal CME score in one year. This method could be useful in assessing the therapeutic efficacy of drugs used in treating such illnesses.

Aged↗
PubMed1996

Changes in blood lymphocyte populations in experimental bowel allograft rejection.

The aim of this study is to measure percentages of lymphocyte populations and IL-2R cellular expression in peripheral blood during the rejection of a small bowel allograft (SBA) in the rat. Thirty rats were allotted to three groups: A, control, no transplantation (Tx); B, rats receiving an orthotopic SBA; C, similar SBA but with thymostimulin (TP-1) administered before Tx, aimed at increasing the intensity of and accelerating rejection. The percentages of CD19, CD5, CD4 and CD8 cells and of IL-2R were determined when rejection was present. Rejection appeared in rats in group B between days 11 and 26 post-Tx and in group C between days 6 and 7 post-Tx (P < 0.001). In both B and C groups, CD5 and CD4 cells decreased (P < 0.005) and CD8 cells increased (P < 0.001). A correlation between CD8 and IL-2R content was found (P < 0.05). In group C, earliness of rejection correlated with the percentage of CD8 cells (P < 0.05) and the intensity of rejection with numbers of CD8 and CD19 cells (P < 0.05).

Animals↗