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Biomedical subjects

G Izquierdo

Publications and source records attributed to G Izquierdo.

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

The oxidation-reduction state of serum proteins in multiple sclerosis patients: effect of interferon beta-1b.

The concentration of reduction equivalents in serum was studied in a cohort of healthy individuals, in a group of multiple sclerosis (MS) patients undergoing treatment with interferon beta-1b and another group of MS patients who refused treatment with interferon beta-1b. Two classes of sulfhydryl groups were detectable in serum: (1) the uncovered sulfhydryls, accessible to the oxidation-reduction substrate 5,5-dithiobis-(-2-nitrobenzoic acid) (DTNB); and (2) the hidden sulfhydryls that required previous heat denaturation of serum proteins to become accessible to DTNB. The concentration of the reduced form of both the uncovered- and hidden-type of sulfhydryls was higher in the serum of MS patients than in healthy individuals. Interferon beta-1b lowered the plasma concentration of the uncovered reduced sulfhydryls after 3 months of treatment. This was in contrast to a minor effect of interferon beta-1b in the hidden-form of sulfhydryl groups. The results suggest that the concentration of reduced sulfhydryls is a biochemical marker of the in vivo oxidation/reduction reactions in MS.

Adult↗
PubMed1999

[Evolution and adverse effects in patients with remittent-recurrent multiple sclerosis treated with interferon beta 1b. The influence of patient's weight and height].

BACKGROUND: The aim of the present study was to determine whether the adverse effects (AE) of interferon beta 1b (IFNb-1b) are related to patient weight, height and body surface area. Moreover, whether the basal incapacity and/or some of these AE may be related to the evolutive prognosis were also studied. METHODS: Twenty-nine females and 14 males with remittent-recurrent multiple sclerosis treated with IFNb-1b were studied. The clinical data and the AE, were compared with the number of outbreaks and the progression of incapacity over the first year of treatment in patients with high weight, height and body surface area with respect to those under the mean. RESULTS: Although the presence of fever was similar in the two groups during the first month (8/19 in the high weight patients and 11/24 in the low weight group), in the following months, overall, the low weight patients continued to present fever. Fever during the first month was associated with a lower number of outbreaks at one year of evolution (0.04 +/- 0.1, n = 19 vs 0.30 +/- 0.5, n = 24; p = 0.04). Furthermore, the patients with lesser incapacity presented a better evolution than those with more incapacity, particularly at 2 years (0.21 +/- 1.3 vs 1.36 +/- 0.9; p = 0.05). CONCLUSIONS: During the first month of treatment fever is very frequent in all the patients regardless of weight and fever was correlated with a lower number of outbreaks at one year of evolution. From the third month fever was less frequent in the lower weight patients group.

Adjuvants, Immunologic↗
PubMed1998

Interferon beta-1b inhibits reactive oxygen species production in peripheral blood monocytes of patients with relapsing-remitting multiple sclerosis.

We studied the rate of reactive oxygen species (ROS) production by monocytes 'ex vivo' in a cohort of healthy individuals, in a group of MS patients undergoing treatment with interferon beta-1b and another group of MS patients who refused treatment with interferon beta-1b. The rate of ROS production in healthy individuals was slightly lower than in non-treated MS patients. The lower rate of ROS production was obtained in monocytes of MS patients treated with interferon beta-1b. These results indicate that the treatment of relapsing-remitting MS patients with interferon beta-1b rendered the NADPH oxidase of the monocytes less sensitive to trigger reactive oxygen species (ROS).

Enzyme Activation↗
PubMed1998

Genotypic identification of an undescribed spotted fever group rickettsia in Ixodes ricinus from southwestern Spain.

An undescribed rickettsia was directly analyzed with specific rickettsial molecular biology tools on Ixodes ricinus L. collected in different localities of the province of Cadiz (southwestern Spain). On the basis of the results of the citrate synthase (glta) gene, 190 kD-outer membrane protein (rOmpA) gene, and 16S ribosomal RNA (16S rRNA) gene partial sequence data, it was found that this rickettsia is sufficiently genetically distinct from other Rickettsia to be considered a distinct taxonomic entity. The isolation and culture of this organism, as well as comparative antigenic analysis, are required to ensure its conclusive taxonomic placement among spotted fever rickettsiae. The epidemiologic role of this new rickettsial agent and its possible pathogenicity to wild and domestic animals or humans is still unknown and needs to be investigated.

Amino Acid Sequence↗
PubMed1998

[Familial cerebral cavernomatosis associated with cutaneous angiomas].

UNLABELLED: OBJECTIVE, PATIENTS AND METHOD: We present a genealogical study of a person with familial cerebral cavernomatosis (CCF) discovered following study of a man who presented with status epilepticus at the age of 35 years. This had also affected another three members of the family consisting of a total of 43 persons, studied over six generations. RESULTS: In the family members studied we did not find cavernomas at other sites but there were dermatological lesions whose relation to cerebral cavernomas (CC) is discussed. CCs are the second commonest type of cerebral vascular malformations. Their major clinical features are epilepsy and cerebral haemorrhage. There are two forms of CC: a sporadic form with single lesions and a familial form with multiple lesions. Although the condition has been recognized since 1854, very little is known about it. Recently a gene causing the familial form has been found on chromasome 7. CONCLUSIONS: We discuss the clinical findings in this family with relation to descriptions in the literature. We emphasize the importance of MR in diagnosis of the condition and for detection of asumptomatic carriers. We consider a possible relationship between these findings and genes which have been mapped, and in view of recent genetic data, the hypothesis of a possible Spanish ancestor with the condition.

Adolescent↗
PubMed1998

[Changes in lymphocyte subsets s and treatment with beta interferon in active multiple sclerosis].

INTRODUCTION: We report that interferon beta decreases CD8 T cells percentage and increases CD4/CD8 cell's rate in vivo in Multiple Sclerosis (MS) patients. PATIENTS AND METHODS: We studied 40 patients (22 women and 18 men) with clinically definite active MS who received IFN beta. Twenty-six were treated with nIFN (9 MU/week) and 14 with rIFN (28 MU/week). All patients except two with secondary progressive forms presented relapsing remitting courses. Mean age and mean age at onset were 36.5 +/- 9 and 27.8 +/- 7 years respectively. Mean EDSS score was 2.96 +/- 1.8. Patients were reviewed at four weeks and every eight weeks and periodical studies of immunity were performed. T cell subpopulations (CD3, CD4, CD8 and NK) were studied byflow cytometry. RESULTS: The evolution of CD8 T cell percentage showed a statistically significant decrease in all blood samples after 20 weeks of treatment with rIFN (24.3 +/- 8 vs 34.7 +/- 5 in the control group) and after 36 weeks for nIFN beta group (25.7 +/- 6 vs 33.0 +/- 4 in the control group). No changes were detected in CD4 T cell subset. The evolution of CD4/CD8 T cell rate showed an increase over the cut-off (2.200) in all blood samples after 20 weeks of treatment with rIFN (2.302 +/- 1.12, 2.332 +/- 0.99 and 2.488 +/- 1.61 for 20, 28 and 36 weeks respectively) and after 52 weeks for nIFN beta group (2.128 +/- 1.07, 2.346 +/- 1.09 and 3.168 +/- 3.87 for 52, 60 and 68 weeks respectively). CONCLUSIONS: Both nIFN and rIFN beta are able in vivo to decrease CD8 percentage of T cells and increase CD4/CD8+ T cell rate. The increase in the rate is produced earlier in the rIFN treated group.

Adult↗
PubMed1997

Internucleosomal breakdown of the DNA of brain cortex in human spongiform encephalopathy.

The analysis of chromatin structure in cases of human spongiform encephalopathies could show the possible involvement of apoptosis in neuronal cell death. Genomic DNA was purified from peripheral blood lymphocytes and from a biopsy of the brain cortex in a case of Creutzfeldt-Jakob disease. Restriction fragment polymorphism with AspI, PvuII, Del and NspI showed the pattern of wild type PrP gene. The DNA purified from the brain consisted of partially degraded DNA in internucleosomal-sized fragments, whereas the DNA from peripheral blood lymphocytes showed the high molecular weight of unbroken DNA. These results are consistent with the possible activation in vivo of the apoptotic endonuclease and the internucleosomal fragmentation of DNA of the brain cortex in the patient affected by Creutzfeldt-Jakob disease, suggesting the involvement of apoptosis in neuronal cell death in human spongiform encephalopathy.

Blood Cells↗
PubMed1997

[Myelographic diagnosis of an epidural arterio-venous fistula].

INTRODUCTION: Epidural arterio-venous fistulae are a little known clinical condition. They are probably commoner than is thought, since diagnosis and angiographic demonstration are difficult. CLINICAL CASE: We present the case of a 49 year old man with the clinical features of chronic myelo-radiculopathy with episodes of intermittent medullary claudication. This shows the use of myelography, which in certain cases allows clear detection of vascular structures which might otherwise pass unnoticed. CONCLUSIONS: One should think of this condition when compatible features are found and there is no other diagnosis, since if confirmed by myelography and/or magnetic resonance prior to angiographic study, it may benefit from embolization, which is an effective treatment for this.

Arteriovenous Fistula↗
PubMed1997

[Neuroborreliosis in a patient with progressive supranuclear paralysis. An association or the cause?].

INTRODUCTION: Many different neurological conditions may be seen in the later stages of Lyme's Disease, such as blindness, epileptic crises, CVA, extrapyramidal disorders, amyotrophic lateral sclerosis, and dementia may be yet another form of presentation of chronic infection due to Borrelia burgdorferi (Bb). Progressive Supranuclear Paralysis (PSP), a disorder of unknown aetiology, considered to be the commonest cause of Parkinsonism-plus, one of the symptoms of which is dementia, has never been mentioned in this type of differential diagnosis. CLINICAL CASE: We present the case of a 78 year old man with sub-acute mental deterioration, Bb positive serology in both plasma and CSF, and with clinical and epidemiological features compatible with Lyme's Disease. Complementary tests were negative. The syndrome corresponded to Lyme's Disease and improved after treatment with ceftriaxona. CONCLUSIONS: We consider aspects of the aetiology of PSP which are still not clear. In our patient, the aetiology seemed to be Bb infection, according to the criteria of the original description of the disease and in view of the neuropathological findings which have shown Bb in the substancia nigra of the mid-brain and the existence of an animal model in which Bb shows a particular tendency to colonize infratentorial structures.

Aged↗
PubMed1995

Treatment of relapsing-remitting multiple sclerosis with natural interferon beta: a multicenter, randomized clinical trial.

Preliminary results of a multicenter, randomized study on the effect of natural interferon beta (n-INFN-beta) in relapsing-remitting MS are reported. Sixty patients received either no treatment or n-IFN-beta (9 MIU three times a week, subcutaneously). After 6 months, the n-IFN-beta-treated group showed a 58% median reduction in the number of active lesions detected on monthly magnetic resonance imaging scans as well as a 38% reduction in the exacerbation rate as compared with the control group. Side-effects were mild and self-limiting. The study continues according to the protocol.

Adjuvants, Immunologic↗
PubMed1994

[Validity of intrathecal secretion formulas of IgG in the follow-up of the response to neurosyphilis treatment].

The different formulas on intrathecal secretion of IgG were evaluated in patients with active neurosyphillis (NS) who did not have HIV infection with the aim of knowing their usefulness and sensitivity in the follow up of response to treatment. Five HIV negative patients with defined criteria of active NS were analyzed. The QAib ratio (albumin LCR/serum x 1,000) and Tourtellotte, Schuller and Reiber formulas of intrathecal secretion and the Link's index were studied prior to and at 15 days and three months following treatment with high intravenous doses of penicillin G over 12 days. A decrease in the QAlb ratio and all the formulas of intrathecal secretion of IgG was observed after treatment. The mean decrease was statistically significant on the third month after treatment for the Tourtellotte formula (116.6 +/- 44 mg/dl in basal control, 60.7 +/- 38 mg/dl at 15 days and 46.5 +/- 59 mg/dl at three months) (p < 0.05). The same evolutive pattern was not observed with the Link's index 1.75 +/- 9 mg/dl in basal control, 1.16 +/- 5 mg/dl at 15 days and 1.79 +/- 1 mg/dl at 3 months) in this series. The formulas of intrathecal secretion of IgG are useful to evaluate the response to treatment of patients with active neurosyphilis. The Tourtellotte formula was shown to be better than the Link index in this evaluation.

Aged↗
PubMed1994

[Positive serology for Borrelia burgdorferi in patients with symptoms compatible with Lyme's disease].

UNLABELLED: The existence of Lyme's disease (LD) in Spain has been demonstrated for several years, but the impact that LD may have on the presence of symptomatology associated to this entity has not been evaluated so far in our region. Given the existence of serological false positives and negatives, the usefulness of positive serology as indicative of LD is discussed. In this work, we try to demonstrate the presence of a greater serological positivity for anti-Bb antibodies in patients with clinical signs compatible with Lyme's disease, in order to assess in our environment if positivity of the serological tests used is indicative of infection by Bb. METHOD: In the Health Center of Pino Montano, we studied a total of 100 patients which could have been in contact with ticks or which presented symptomatology compatible with Lyme's Borreliosis, no other explantation being plausible. Determinations were made using indirect immunofluorescence (IIF) at different dilutions and three commercial ELISA methods in each serum. RESULTS: Seropositivity for IIF at a dilution 1/128 was of 24%, similar to the one obtained with 3 different ELISA methods. This results were confirmed for each of the risk factors considered. Fever from unknown etiology was present in 33% of the cases and was associated to a higher risk of positive serology. When two systems were affected (probable LD), seropositivity was more frequent than when just one system was affected (possible LD). Advanced age in the study population was not associated to a greater risk of positive serology, the opposite of what happened in the control population. CONCLUSIONS: The presence of anti-Bb antibodies in a risk population (probable or possible LD) is 24%, much greater than in the control population. Techniques for anti-Bb antibodies detection using ELISA methods show a significant correlation between each other and with IIF at a dilution of 1/128.

Adolescent↗