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Biomedical subjects

M Ortega

Publications and source records attributed to M Ortega.

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

Cerebrospinal fluid HIV-1 RNA levels in asymptomatic patients with early stage chronic HIV-1 infection: support for the hypothesis of local virus replication.

OBJECTIVE: To assess HIV-1 RNA levels in cerebrospinal fluid (CSF) and their potential correlation with plasma viral load and central nervous system (CNS) HIV-1 infection markers in stable asymptomatic patients with a CD4 T cell count >500x10(6) cells/l. PATIENTS AND METHODS: Consecutive patients screened for two trials were eligible for lumbar puncture assessment. At day 0, simultaneous samples of CSF and plasma were obtained and levels of total proteins, albumin, IgG, antibodies against HIV-1 p24 antigen, HIV-1 RNA (using the polymerase chain technique) and white cells were measured. RESULTS: The integrity of the blood-brain barrier was preserved (albumin index > or =7) in 59 out of 70 patients (84%). Intrathecal production of antibodies against HIV-1 p24 antigen was demonstrated in 55 out of 70 individuals (78%). Viral load in CSF was significantly lower than plasma values (3.13+/-0.95 versus 4.53+/-0.53, P = 0.0001). HIV-1 RNA was not detected in CSF in only three of the 70 patients (4%). Overall, there was a significant correlation between plasma and CSF HIV-1 RNA levels (r = 0.43, P = 0.0001); however, in 29 patients (41%) there were significant differences (>1.5 log10 copies/ml) between the viral loads in plasma and CSF. In the multivariate analysis, a high level of protein and white cells in CSF, but not the HIV-1 RNA plasma level, were factors independently associated with a higher level of HIV-1 RNA in CSF (P = 0.0001). CONCLUSIONS: HIV-1 RNA can be detected almost always in CSF of asymptomatic patients in early stages of HIV-1 infection including those with a preserved integrity of the blood-brain barrier. The important discrepancies between plasma and CSF viral load, and the independent association between CSF abnormalities and CSF viral load, support the hypothesis of local production of HIV-1.

Adult↗
PubMed1999

[Disseminated cryptococcosis in patients with AIDS. Prognostic factors of poor outcome].

BACKGROUND: The objectives of this study were to analyze the changes in the incidence of cryptococcal disease in the last 10 years (1987-1997) and to assess the factors of poor prognosis in HIV-1 infected patients. PATIENTS AND METHODS: Clinical records of HIV-1 infected patients diagnosed with cryptococcal infection from June 1987 to December 1997 at Hospital Clinic i Provincial in Barcelona, Spain, were examined. An univariate and multivariate analysis of the predictors of poor outcome was performed. RESULTS: Sixty clinical records were analyzed. The number of cases per 100 exposed patients per year decreased from 1991 to 1993 and, afterwards, decreased again from 1996. Fifty patients had a resolution of clinical symptoms, 17 out of this 50 patients (34%) had a relapse. Factors associated with a higher risk of relapse were a positive blood culture and cryptococcal antigen title in cerebrospinal fluid above 1/1.024. CONCLUSIONS: The decrease in the number of cases of cryptococcal infection coincides with the broad use of triazole antifungal drugs for oral candidiasis (1990-1991) and, afterwards, with the initiation of highly active antiretroviral therapy (1996). The best predictors of relapse are a positive blood cryptococcal culture and a high titter of cryptococcal antigen.

AIDS-Related Opportunistic Infections↗
PubMed1999

Follow-up of chimerism in children with hematological diseases after allogeneic hematopoietic progenitor cell transplants.

Using in situ hybridization with an X and Y chromosome probe mixture, 106 bone marrow samples from 38 patients with malignant and non-malignant hematological diseases who received sex-mismatched allogeneic hematopoietic progenitor cell transplants (PCT) in a single institution within short-term intervals (1, 3, 6, 12, 24 and >24 months) have been sequentially studied. The patients received either HLA-identical (n = 31) or non-identical (n = 7) PCT. Twenty-six children showed donor chimerism, 10 children showed mixed chimerism (MC) and two children presented autologous reconstitution. Chimerism status with different parameters has been related (age, sex, donor, disease status before PCT, conditioning regimen, GVHD prophylaxis, relapse, GVHD and survival). Our results indicate that female patients (P = 0.011) and a less intensive conditioning regimen (P = 0.039) are significantly associated with the MC status. Mixed chimerism is not, per se, significantly associated with leukemia relapse but an increase of the MC is indicative of clinical relapse.

Adolescent↗
PubMed1998

Efficacy of anticoagulation post-inferior vena caval filter placement.

Anticoagulation with heparin or Coumadin is usually effective in the management of deep vein thrombosis; however, if anticoagulation treatment is contraindicated, is ineffective, or leads to adverse effects, inferior vena caval (IVC) placement of a filter is indicated. The purpose of this study is to determine whether increased early adverse effects are present in patients not given anticoagulation medication after placement of an IVC filter. The records of 240 consecutive patients who received IVC filter placement were reviewed for indications for placement, as well as for whether patients received anticoagulation medication on discharge. There were 41 in-patient mortalities. Of the remaining 199 patients, 100 were discharged and prescribed anticoagulation medication, and 99 were not. Patients were followed for 3 to 60 months. These results suggest that no early adverse effects are seen in patients who are not given anticoagulants after IVC filter placement.

Adult↗
PubMed1997

Effects of chitinolytic and proteolytic enzymes on in vitro phagocytosis of microsporidians by spleen macrophages of turbot, Scophthalmus maximus L.

The serum of many teleosts, including turbot, contains chitinolytic and proteolytic enzymes. In the present study, the possible role of these enzymes in nonspecific immune responses to microsporidian infection was investigated. The rate of phagocytosis of Glugea caulleryi spores by turbot splenic macrophages was significantly reduced after pretreatment of spores with proteolytic or chitinolytic enzymes, suggesting that alteration of surface glycoproteins affects spore recognition. However, intracellular superoxide production by macrophages was significantly higher after stimulation with protease-treated spores, or with untreated spores plus normal turbot serum (NTS), than after stimulation with untreated spores in the absence of NTS. These results support the view that the chitinolytic and proteolytic activities in teleost serum may play a role in defence against microsporidian infection.

Animals↗
PubMed1997

Intraoperative control by somatosensory evoked potentials in the treatment of cervical myeloradiculopathy. Results in 210 cases.

Somatosensory evoked potentials (SEPs) were used for continuous monitoring of 210 patients during anterior surgery for cervical myeloradiculopathy, to test how effectively they help avoid irreversible neurological damage during surgery. The pathologies differed in severity and were treated by diskectomy or by extended corporectomy using the Senegas technique. Intraoperative SEP changes were recorded in 84 patients (40%); in 13 (6.2%) of these, changes in SEP amplitude and latency were caused by mechanical stress. SEPs revealed transient episodes of regional ischaemia or neurophysiological anomalies during anaesthesia (mainly hypotension) in 27 patients (12.8%). The traces detected incipient and potentially dangerous mechanical pressure on, or metabolic anomalies of, the spinal cord during manipulation and placement procedures of spinal fixation devices. They were particularly sensitive indicators of ischaemia; one of the most common causes of irreversible injury. The traces of 44 patients (21.0%) improved markedly during surgery. There were no false-negatives in this series and, thanks to the fact that SEPs gave immediate warnings of incipient ischaemia to the surgical team, we had no case of irreversible medullary or nerve-root deficit.

Adult↗
PubMed1997

A radiation hybrid map of human chromosome 5 with integration of cytogenetic, genetic, and transcript maps.

One of the major goals of the human genome project is to establish a physical map of each human chromosome with a density of sequence-tagged site (STS) markers exceeding one every 100 kb. We report here the generation of a human chromosome 5-specific radiation hybrid (RH) map that includes 556 markers. Of these markers, 132 loci are ordered with a maximum likelihood ratio of >1000:1 compared with the next most likely order. An additional 113 loci were ordered relative to these backbone markers with a maximum likelihood ratio of >10:1 but <1000:1. Together, these 245 loci form an ordered framework map for the chromosome. Using this framework, >300 more markers were localized based on two-point analysis with the ordered set. On average, there are 50 markers in common with the RH map presented here and other chromosome 5 maps included in the current whole genome cytogenetic, genetic, and physical maps. The accuracy of all the maps is evident in that there are no more than two discrepancies between any one of them and these data. All of the maps encompassing chromosome 5 complement each other providing excellent STS coverage with >2200 loci combined. The chromosome 5-specific RH map contains 20% of these independent loci. In addition, our RH map contains STSs derived from clones suitable for fluorescent in situ hybridization, allowing alignment to the cytogenetic map. Together, these maps will assist in the assembly of sequence-ready contigs and will aid in the identification of disease loci on chromosome 5 by positional cloning and positional candidate approaches.

Centromere↗
PubMed1997

Congenital tibial aplasia with preaxial polydactyly. A case report.

An anatomical study of a left lower limb with congenital tibial aplasia and preaxial polydactyly amputated at 10 months of age was carried out. The tibia was replaced by a fibrous band (a band of connective tissue) and there were four cuneiforms, six metatarsal bones and seven toes. The second metatarsal bone showed characteristics of the hallux. An intermuscular septum which showed an orifice for the anterior tibial artery was found on the medial side of the leg and foot. All the muscles of the leg and foot were present except for the tibialis posterior muscle, which was replaced by two atypical muscles. No muscular attachments reached the fibrous band. Several intertendinous connection bands were found. Also, an accessory muscular belly split from the tibialis anterior tendon and attached to the common flexor tendinous sheet of the foot. An unusual motor branch of the deep peroneal nerve ran together with this belly to supply the intrinsic muscles of the hallux. We also observed other minor anomalies of the nerve pattern. The arterial pattern was complete, except for some arteries which showed both an anomalous origin and course. The findings of this study suggest that the development of the skeletal elements plays an important role in the differentiation of the muscles, tendons, arteries and nerves. We postulate that a dysmorphogenic event involving the development of the tibial field of the limb could give rise to both defective histodifferentiation of the tibia and defective programmed cell death in the pre-hallucial anlage. These anomalies would determine secondary adaptations of muscles, tendons, vessels and nerves of the limb.

Abnormalities, Multiple↗
PubMed1997

Acne keloidalis nuchae and tufted hair folliculitis.

Acne keloidalis nuchae is a chronic, scarring folliculitis that affects mostly black patients and is located on the back of the neck of young adults. The course is progressive and leads to hypertrophic scarring, chronic abscesses and hair loss. We discuss the relationship between acne keloidalis and tufted hair folliculitis, pointing out the possibility that tufted hair folliculitis is not a specific disease but secondary to other progressive folliculitis like folliculitis decalvans, dissecting cellulitis or acne keloidalis.

Abscess↗
PubMed1997

Autocrine modulation of IL-8 production by sputum neutrophils in chronic bronchial sepsis.

We examined the activity of neutrophils isolated from sputum and blood of subjects with chronic bronchial sepsis in terms of interleukin-8 (IL-8), IL-1beta, and tumor necrosis factor-alpha (TNF alpha) production. In sputum, the numbers of neutrophils correlated with the concentrations of these cytokines. Sputum neutrophils constitutively secreted large amounts of IL-8, IL-1beta, and TNF alpha. The patterns of secretion, however, differed from those of blood neutrophils stimulated with bacterial lipopolysaccharide (LPS). Cytokine secretion was time-dependent and was inhibited by cycloheximide and dexamethasone. IL-10 inhibition of IL-8 production by sputum neutrophils was significantly less than that noted with activated neutrophils. Antibody to IL-1beta but not to TNF alpha, inhibited IL-8 secretion by sputum neutrophils, contrasting with results found using blood neutrophils. Incubation of blood neutrophils in sputum sol induced a similar cytokine secretion profile to that following exposure to LPS. The inhibitory effects on IL-8 protein production correlated with messenger RNA (mRNA) gene expression. These observations indicate that neutrophils are a significant source of IL-8 in purulent sputum, and that an autocrine loop involving IL-1beta maintains secretion within the bronchus lumen.

Blood↗
PubMed1997

[Dengue in Panama, 1993].

Up to 1993, Panama was the only country in Central America where the autochthonous transmission of dengue virus had been detected without experimenting an explosive epidemic despite being reinfected with the Aedes aegypti mosquito since 1985. The characteristics of this first outbreak reported on November 19, 1993, are described in this paper. It is shown that even when there is a Program for the Surveillance and Control of Dengue, which considers low levels of Aedes aegypti infection and a system for the early detection of the virus, the epidemics appear if the community does not take an active part as it happened in 1994, 1995, and 1996. The 14 cases reported were located in an area under the responsibility of the Health Center in San Isidro, Belisario Porras, Special District of San Miguelito, in Panama City (13 cases in 4 blocks of the sector of Santa Librada and 1 case in San Isidro Valley). 3 patients were under 15 and 8 over 36, the other 3 were between 15 and 24.9 were females. The dengue type 2 virus was isolated in 3 patients. The presence of IgM and IgG antibodies to dengue was demonstrated in 11 patients, whereas in 8 over 20 it was observed a secondary type answer. According to the clinical picture, the epidemic was classified as dengue fever. The seroepidemiological survey carried out in the sector of Santa Librada and its surroundings 5 months after the appearance of the symptoms in the first case showed a prevalence of antibodies to dengue of 5.7% (46/802), mainly among individuals over 44. These results confirmed that the outbreak was geographically limited.

Adolescent↗
PubMed1996

The role of opsonization by antibody and complement in in vitro phagocytosis of microsporidian parasites by turbot spleen cells.

We investigated the role played by opsonization by antibody and complement in in vitro phagocytosis of microsporidian spores by turbot adherent phagocytes. Most turbot adherent cells displaying phagocytic activity are probably macrophages. Phagocytosis of yeast cells and polystyrene beads was greatly enhanced in the presence of both the Ig and the non-Ig (i.e. complement-containing) fractions of normal turbot serum, but phagocytosis of Glugea caulleryi or Tetramicra brevifilum spores was not affected by either fraction. Neither anti-G. caulleryi immune serum, nor anti-T. brevifilum immune serum (which cross-reacted considerably with G. caulleryi antigens), enhanced phagocytosis of G. caulleryi spores. Finally, spores treated with sodium m-periodate (to modify the structure of surface-borne sugars) were less effectively ingested than untreated spores, suggesting that phagocytosis of microsporidian spores involves recognition of such sugars by the phagocytic cell. The results of this study support the hypothesis that microsporidian parasites of fish in some way modulate the host phagocytic responses.

Animals↗
PubMed1996

The humoral immune response of turbot, Scophthalmus maximus L., to spore-surface antigens of microsporidian parasites.

Experiments based on enzyme-linked immunosorbent assay (ELISA) revealed considerable antigenic homology in turbot between two species of microsporidian, Tetramicra brevifilum (a parasite of the turbot, Scophthalmus maximus) and Glugea caulleryi (a parasite of the lesser sand-eel, Ammodytes tobianus). We next investigated whether G. caulleryi is able to suppress the turbot immune response. Intraperitoneal inoculation of turbot with G. caulleryi spores (whether heat-killed or viable) did not suppress the humoral immune response to injection of G. caulleryi spores plus adjuvant 15 days later; in fact, specific serum antibody levels (as revealed by ELISA) reached maximum levels by about Day 30 post re-exposure. Similar results were obtained with cellular enzyme-linked immunosorbent assay: 15 days after injection with G. caulleryi spores plus adjuvant, specific antibody secretion rate was higher in turbot which had been pre-exposed to G. caulleryi spores than in turbot which had not been pre-exposed.

Animals↗
PubMed1995

[False aneurysm of the posterior tibial artery complicating fracture of the tibia and fibula].

PURPOSE OF THE STUDY: Although tibia and fibula fractures are common, associated injury of the posterior tibial artery is rare. We present an unusual case of pseudoaneurysm of posterior tibial artery complicating a closed tibial and fibular fracture. MATERIAL: A 21-year-old man injured his left leg while playing football. METHOD: The diagnosis was suspected by the presence of persisting painful swelling at the fracture site. Echography, and later angiography confirmed it. RESULT: The patient was successfully treated with a saphenous vein interposition graft. The tibial fracture was stabilized with a Küntscher nail, and five months after surgery the fractures healed. DISCUSSION: A review of the literature revealed only 11 civilian cases of pseudoaneurysm of the posterior tibial artery. The clinical signs, specific diagnosis and operative treatment are discussed. CONCLUSION: Our case emphasizes that attention must be paid to the vascular complications of fractures, that may not become evident until some time after the initial injury.

Adult↗