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Biomedical subjects

F Quintana

Publications and source records attributed to F Quintana.

At least 19 recordsLinked to original sources
PubMed2004

Blocking of the placental immune-modulatory ferritin activates Th1 type cytokines and affects placenta development, fetal growth and the pregnancy outcome.

BACKGROUND: Placenta immunomodulatory ferritin (PLIF) cDNA was recently cloned from the human placenta, where it is expressed in syncytiotrophoblast and decidual mononuclear cells. PLIF and its subcloned bioactive domain (C48), expressed in Escherichia coli, are immunosuppressive proteins and induce pronounced IL-10 production in vitro and in vivo. METHODS AND RESULTS: PLIF serum level, measured by enzyme-linked immunosorbent assay, was elevated in pregnant mice throughout gestation and declined towards delivery. Blocking of PLIF activity by vaccination of mice with C48 prior to mating inhibited pregnancy development. Passive transfer of anti-C48 immunoglobulin (Ig) starting at 3.5-12.5 days post coitum (dpc) resulted in high rate of embryo resorption. Furthermore, treatment with anti-C48 Ig resulted in placental and embryonal growth restriction. At gestation day 13.5, growth retardation was especially notable in the placentae, while at 16.5 dpc it was pronounced in the embryos. Histopathological examination revealed that experimental placentae were globally hypoplastic and the labyrinth was strikingly pale and contained less maternal blood compared with control. Immune-activated spleen cells harvested at 13.5 dpc from anti-C48 Ig-treated pregnant mice secreted in vitro increased level of Th1 cytokines (IL-2, TNF-alpha, IL-12) and decreased level of Th2 cytokines (IL-10, IL-4, IL-5, IL-6) as compared with the level of the respective cytokines secreted by spleen cells from control pregnant mice. CONCLUSION: This study provides the first in vivo evidence that PLIF plays a major role in placentation and embryonic growth.

Animals↗
PubMed2001

[Common bilio pancreatic channel syndrome in adults].

BACKGROUND: The Common Channel Syndrome (CCS) is defined as the union of the biliary and pancreatic ducts outside of the duodenal wall with a common duct more than 15 mm long. It is classified morphologically in types 1 and 2, whether it is the biliary or the pancreatic duct the one that predominates. CCS is uncommon in Western countries. It is described particularly in children and has not yet been reported in Chile. AIM: To report the frequency of CCS among patients subjected to endoscopic retrograde cholangiopancreatography (ERCP). PATIENTS AND METHODS: Between 1992 and 1998, 1860 ERCPs were performed for the diagnosis of biliary or pancreatic diseases. RESULTS: In six patients (0.35%) a CCS was diagnosed (3 type 1 and 3 type 2). All patients presented with pain and three with jaundice. Four patients had a previous cholecystectomy, three due to cholelithiasis and one due to gallbladder cancer. A common bile duct resection and bilioenteric anastomosis was done in three patients with a favorable outcome. Two patients with an advanced age and one with a gallbladder cancer, were not operated. CONCLUSIONS: CCS was found in 0.35% of patients subjected to an ERCP. It frequently presents in association with one or more bilio-pancreatic diseases: cholelithiasis, choledocolithiasis, cholangitis, pancreatitis and gallbladder cancer. Resection of the common bile duct and a bilio-enteric anastomosis is proposed as the surgical treatment.

Adult↗
PubMed1999

Acceleration of autoimmune diabetes by cyclophosphamide is associated with an enhanced IFN-gamma secretion pathway.

Cyclophosphamide (CY), an alkylating cytostatic drug, is known for its ability to accelerate a number of experimental autoimmune diseases including spontaneous diabetes in NOD mice. The mechanism(s) by which CY renders autoreactive lymphocytes more pathogenic is largely unknown, but it has been postulated that the drug preferentially depletes regulatory (suppressor) T cells. It has been suggested that in cell-mediated autoimmune diseases, Th2-like lymphocytes secreting IL-4 and/or IL-10 provide protection, while Th1-like cells secreting IFN-gamma are pathogenic. In this study, we analysed the effects of CY on autoimmune diabetes and cytokines in two mouse models: the spontaneous diabetes of NOD mice and the diabetes induced in C57BL/KsJ mice by multiple injections of low dose streptozotocin (LD-STZ). In both models, CY induced severe lymphopenia and accelerated the progression to hyperglycemia. This was associated with changes in splenic cytokine patterns indicating a shift towards the IFN-gamma-secreting phenotype. We provide here evidence that IFN-gamma producers are relatively resistant to depletion by CY and that Th0 clones can be shifted towards Th1. However, direct exposure of T lymphocytes to CY may not be a necessary condition for exacerbation of diabetes; NOD.scid mice treated with CY before adoptive transfer of NOD splenocytes developed diabetes at a higher rate than did controls. Thus, the acceleration of diabetes by CY seems to be a complex event, which includes the relatively high resistance of IFN-gamma producers to the drug, their rapid reconstitution, and a Th1 shift of surviving T cell clones.

Animals↗
PubMed1997

Immunization with recombinant Trypanosoma cruzi ribosomal P2beta protein induces changes in the electrocardiogram of immunized mice.

Molecular expression cloning techniques revealed that patients with severe chronic Chagas heart disease showed a strong humoral response against the cloned C-terminal portion of the Trypanosoma cruzi ribosomal P2beta protein, previously named JL5. The main linear epitope of this polypeptide was mapped to the 13 C-terminal amino acid sequence EEEDDDMGFGLFD (named R13), which is almost identical to the mammalian ribosomal P consensus sequence EESDDDMGFGLFD (named H13). Enzyme-linked immunosorbent assay measurements demonstrated that sera from patients with chronic Chagas heart disease presented a very specific anti-P humoral response with high anti-R13, but low H13 antibody levels. We attempted to develop an animal model that would reproduce, at least partially, two features of the human infection: (1) the serological pattern of the anti-P response, and (2) specific cardiac symptoms. To this effect, mice were immunized with T. cruzi P2beta recombinant protein. Immunization reproduced the typical anti-P antibody profile defined for chronic infections, but did not induce cardiac inflammatory lesions. However, it altered significantly the electrocardiograms of immunized mice. It is suggested that this assay represents a functional test for assessing the biological activity of antibodies against T. cruzi ribosomal P protein on cardiac muscle.

Animals↗
PubMed1996

Traumatic aneurysm of the basilar artery.

We report a case in which a "false" aneurysm of the basilar artery developed after an assault on a patient resulting in head injuries. Diagnostic imaging and endovascular treatment are described. Formation mechanisms of traumatic intracranial aneurysms are discussed and the literature is reviewed.

Adult↗
PubMed1994

Cervical schwannoma presenting as a spinal subdural haematoma.

We report a case of cervical spinal subdural haematoma as the presenting manifestation of a small intradural schwannoma. In patients without a bleeding diathesis and an apparently spontaneous spinal subdural haematoma, the possibility of an underlying tumour should always be considered.

Aged↗
PubMed1993

A prospective study of stroke in young adults in Cantabria, Spain.

BACKGROUND AND PURPOSE: The aim of this study was to determine the incidence, type, and prognosis of stroke in young adults in Cantabria, Spain. METHODS: We investigated prospectively all patients aged 50 years or below who were admitted with the diagnosis of a stroke to the University Hospital "Marqués de Valdecilla" from April 1, 1986, to March 31, 1988. This is the main hospital of the region to which all patients with neurological problems are referred. These patients underwent a complete clinical and laboratory assessment for stroke and had 1-year mean follow-up. RESULTS: The total series included 81 patients. The annual age-specific crude incidence rates of stroke were 17.3 and 10.4 per 100,000 for males and females, respectively. Twenty-four patients (30%) were diagnosed as having nonembolic cerebral infarction, 14 (17%) embolic cerebral infarction, 20 (25%) subarachnoid hemorrhage, 22 (27%) spontaneous cerebral hemorrhage, and one case (1%) cerebral venous thrombosis. Eighteen patients (22%) died within 30 days of the cerebrovascular event, and two others died during the follow-up period. Seventy-nine percent of the survivors recovered and were completely self-sufficient. CONCLUSIONS: The incidence of stroke in the young found in Cantabria is comparable with that in previous studies. The initial hospital mortality was not negligible, but the prognosis among the survivors was favorable.

Adolescent↗
PubMed1990

Basichondrocranium anomalies in adult Chiari type I malformation: a morphometric study.

The purpose of this study was to determine the frequency of anomalies of the basichondrocranium in a series of 42 patients with Chiari type I malformation compared with a control group of 46 subjects. Sixteen patients also had syringomyelia. Linear, angular and posterior fossa surface area measurements were taken on conventional lateral skull x-rays. Posterior fossa volume was estimated by CT scanning. In patients there was shortening of clivus length, Twining-opisthion distance and Chamberlain's line. Basal and Boogard angles were enlarged. The size of the posterior fossa was smaller in patients than in controls. Only 10 (23.8%) patients had no evidence of occipital dysplasia. When discriminant analysis was applied to the data, the most discriminative variables were posterior fossa area and clivus length which allowed accurate identification of 76% of patients as belonging to the patient group and 79% of controls as belonging to the control group. These findings prove that under-development of the basichondrocranium with a small size of the posterior fossa is an outstanding feature in adult Chiari type I malformation, and support the hypothesis that tonsillar ectopia is secondary to the disproportion between the posterior fossa and the cerebellum, which is forced to grow into the cervical spinal canal.

Adult↗
PubMed1985

Late onset epileptic seizures. A retrospective study of 250 patients.

A retrospective study of 250 patients with late-onset epilepsy was carried out. The ages ranged from 22 to 88. The seizures were partial in 104 patients and generalized in 146. The neurological examination was abnormal in 41 patients and normal in 209. The EEG studies and CT scan revealed abnormalities in 76.5% and 50.8% respectively. The most frequent CT scan findings were diffuse atrophy (19.2%), tumors (16.4%) and cerebral infarct (8.8%). The clinical parameters which best predicted the CT scan abnormalities were an abnormal neurological examination and simple partial seizures. In seven of the 45 patients with space-occupying lesions, the clinical examination and EEG were normal. The etiology of the convulsions was established in 201 patients, the most frequent cause being chronic alcoholism (62 cases), tumors (41 cases), postischemic vascular epilepsy (33 cases) and postraumatic epilepsy (28 cases). We conclude that a CT scan is essential in the assessment of patients with epileptic convulsions of late onset, even when the EEG and clinical examination are normal.

Adult↗
PubMed1983

Occipital dysplasia and Chiari type I deformity in a family. Clinical and radiological study of three generations.

Three generations of a family affected by a craniocervical malformation (CCM) were subjected to clinical and radiological studies. Occipital dysplasia (OD) and Chiari type I deformity (CD.I) were the main features, inheritance being autosomal-dominant. The malformation was variably expressed; it ranged from OD with basilar impression (BI) to OD without BI and from CD.I with OD to CD.I without obvious osseous malformation. Its pathogenesis, and that of other related familial disorders (Klippel-Feil syndrome and syringomyelia), is discussed, the conclusion being drawn that all were elements of one genetic disorder which finds expression in a very variable sequence. The value of high-resolution CT in the detection of asymptomatic carriers is emphasized.

Adult↗
PubMed1983

Livedo reticularis and cerebrovascular lesions (Sneddon's syndrome). Clinical, radiological and pathological features in eight cases.

Eight patients with diffuse livedo reticularis and cerebrovascular lesions (Sneddon's syndrome) are reported. The disorder was inherited by autosomal dominant transmission in 3 cases. Multiple occlusions in medium-sized arteries were demonstrated by cerebral and hand arteriograms. Digital artery biopsies showed intimal hyperplasia in 7 cases and recanalized thrombosis in one case. Our findings are compared with an extensive review of the literature. Differential diagnosis with other vascular disorders, especially cerebral thromboangiitis obliterans and the corticomeningeal angiomatosis of Divry and Van Bogaert is considered. We conclude that Sneddon's syndrome is a new genetic and progressive arteriopathy, occlusive and noninflammatory, involving medium-sized vessels. The pathogenesis has yet to be elucidated.

Adolescent↗