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Biomedical subjects

A Montero

Publications and source records attributed to A Montero.

At least 55 records · Page 3Linked to original sources
PubMed1999

Coronary artery occlusion and myocardial infarction: a seldom encountered complication of blunt chest trauma.

Myocardial infarction is a rare complication that can occur after blunt chest trauma. The authors describe a 30-year-old man who experienced a fatal anterolateral myocardial infarction after chest trauma in a motorcycle accident. The electrocardiogram and creatine phosphokinase-MB isoenzymes levels suggested myocardial necrosis. Tc-99m phosphate myocardial scintigraphy identified an extensive doughnut-shaped uptake over the cardiac area. An echocardiogram revealed severe left ventricular impairment. Coronary angiography confirmed complete occlusion of the proximal left anterior descending coronary artery.

Adult↗
PubMed1999

Prostaglandins regulate the expression of fibroblast growth factor-2 in bone.

We examined the effect of PGs, particularly PGF2alpha, on basic fibroblast growth factor-2 (FGF-2) messenger RNA (mRNA) and protein in the rat osteoblastic cell line Py1a and in fetal rat calvariae. Py1a cells expressed multiple FGF-2 mRNA transcripts. PGF2alpha dose-dependently increased the 6-kb transcript at 6 h. The selective PGF2alpha agonist, fluprostenol (Flup), was more potent than PGF2alpha. Phorbol myristate acetate (10(-6) M) also increased a 6-kb mRNA at 6 h. By immunofluorescence microscopy, Flup increased perinuclear staining for FGF-2 protein at 6 h and nuclear labeling at 24 h. Immunogold labeling of calvariae revealed that treatment with Flup for 3 h caused a transition of FGF expression from matrix to cells and an increase in cytoplasmic labeling for FGF-2 protein in periosteal cells and in osteoblasts. After treatment with Flup for 24 h, nuclear labeling was marked in periosteal cells and in osteoblasts, and a further increase in cytoplasmic labeling for FGF-2 was noted in osteocytes, periosteal cells, and osteoblasts. We conclude that PGs can increase FGF-2 mRNA and protein in bone cells. Because the effect of Flup was mimicked by phorbol myristate acetate, we hypothesize that PGs' regulation of FGF-2 is mediated by a PGF2alpha-selective receptor acting through protein kinase C. Hence, effects of PGs on bone remodeling may be mediated, in part, by endogenous FGF-2.

Animals↗
PubMed1999

[Localization by bone SPET of osteoid osteoma in the vertebral lamina].

The combined use of bone SPET and CT was a good approach for diagnosing an osteoid osteoma of spine in a 16-year-old young woman with a history of several months of back pain. Pain was increased at night and relieved by aspirin intake. Plain films of the spine only revealed a scoliosis. Bone SPET demonstrated a focal increased activity in the left posterior elements of T12 vertebra. CT of this vertebra discovered a lytic lesion in the left lamina. An osteoid osteoma was removed by laminectomy.

Adolescent↗
PubMed1999

[Effects of treatment with OKT3 on brain perfusion in a heart transplant patient with SPET with 99mTc-HMPAO].

A heart transplant patient treated with OKT3 developed a severe headache which worsened and was accompanied by a sudden decrease in the patient's consciousness level and aphasia when the treatment course was completed. CT was performed and was normal. SPET imaging with 99mTc-HMPAO of cerebral blood flow done 16 hours later revealed multiple and clear focal defects in the blood flow. Analysis of cerebral spinal fluid revealed aseptic pleocytosis. Five days after the completion of treatment, the symptoms remitted and a new control SPET 3 weeks later was completely normal. A diagnosis of neurotoxicity secondary to OKT3 administration was established.

Adult↗
PubMed1999

[Follow-up in lung transplant by the study of the pulmonary epithelial permeability and the pulmonary scintigraphies of ventilation and perfusion: preliminary results].

INTRODUCTION: Acute rejection is the most common complication in lung transplantation. OBJECTIVE: This work aimed to assess the contribution of pulmonary clearance of radioaerosols and relative pulmonary perfusion to diagnose acute rejection in lung transplantation. MATERIAL AND METHOD: We have designed a prospective study and present the results obtained for the preliminary phase. This work includes 5 patients who have received a lung transplantation and in whom 28 studies of pulmonary clearance of 99mTc-DTPA and relative pulmonary perfusion with 99mTc microspheres were performed. The pulmonary biopsy diagnosed 9 rejection episodes, 2 associated to CMV infection. RESULTS: The mean radioaerosol clearance time increased when the follow-up was favorable and decreased in 6 of the 9 rejection episodes, including 2 associated to CMV infection. There was only one case with decreased mean clearance time that was not associated to rejection. CONCLUSIONS: Calculating relative pulmonary perfusion can be useful in the follow-up of single lung transplantation but not in bipulmonary ones. Our results suggest that measuring 99mTc-DTPA clearance is useful to suspect a rejection episode.

Adult↗
PubMed1998

Rapid spontaneous resolution of acute subdural hematoma and HIV related cerebral atrophy: case report.

BACKGROUND: The natural history of a traumatic acute subdural hematoma is usually interrupted by its prompt surgical removal. Rapid spontaneous resolution within 48 hours, although infrequently reported, may be, underestimated and demonstrates a benign course of this condition. To our knowledge, this is the first case of rapid spontaneous resolution of an acute subdural hematoma in a patient with HIV encephalopathy and cerebral atrophy. METHODS AND RESULTS: This 27-year-old man, an intravenous drug user with AIDS-related complex and HIV encephalopathy, suffered an acute subdural hematoma due to head injury in a car accident. The hematoma spontaneously resolved within 12 hours, resulting in a favorable outcome with nonoperative treatment. CONCLUSIONS: AIDS related cerebral atrophy may not only have predisposed the patient to the development of an extracerebral collection, but may have also favorably influenced the spontaneous resolution of the hematoma. The mechanism of the hematoma resolution and the influence of HIV related cerebral atrophy is discussed.

AIDS Dementia Complex↗
PubMed1998

Human 15-lipoxygenase gene promoter: analysis and identification of DNA binding sites for IL-13-induced regulatory factors in monocytes.

In order to study the transcriptional control of 15-LO expression, we have cloned and sequenced the human 15-LO promoter region. The 15-LO promoter is associated with a CpG island at the 5'-end of the gene, and sequence analysis reveals putative Sp1 and Ap2 binding site/s and absence of TATA or CAAT motifs. Transcription is initiated at one major site. Using deletion constructs, we have defined an active promoter region of 1056 bp. Gel-shift assays revealed that transcriptional factor(s) induced only in response to IL-13 treatment of human peripheral blood monocytes bind to the 15-LO promoter DNA. Two regions, DP1 (-140 to -92 bp) and DP2 (-353 to -304 bp) of the promoter were essential for transcription in HeLa cells and human peripheral monocytes. Hela nuclear extracts contained a specific nuclear factor(s) binding to 15-LO promoter DNA which are distinct from those derived from IL-13-treated human peripheral monocyte nuclear extracts. In addition, fluorescent in situ hybridization (FISH) results refined the previous localization of 15-LO to human chromosome 17p13.3.

Animals↗
PubMed1998

Prolactin levels in the cerebrospinal fluid of patients with HIV infection and AIDS.

The objective of this study was to assess the levels of prolactin (PRL) in cerebrospinal fluid (CSF) of HIV-infected patients with regard to nonHIV-infected patients, and to assess the levels of prolactin in the CSF of HIV-infected patients with and without neurological HIV-involvement. Seventeen HIV-infected patients with different degrees of immunological and neurological involvement were studied. A second group of six HIV-seronegative patients with varying clinical conditions requiring lumbar punctures were included as controls. CSF was collected from patients and controls. Patients were studied neurologically and neuropsychologically, and computed tomography of the brain were performed. They were staged according to CDC clinical classification for HIV infection, and on the basis of tomographic findings into one of five stages. An additional classification for neurological involvement in AIDS was used. CD4+ cell counts, CSF studies, serum-prolactin levels and CSF-prolactin levels were performed as principal laboratory tests. CSF PRL concentrations were significantly higher in the HIV-infected group (n = 17) than the nonHIV infected control group (n = 6) (mean +/- s.d.; 5.77 +/- 2.22 vs. 3.53 +/- 0.69 x 10(-6) g l-1, respectively; p = 0.009, Mann-Whitney U-test). Moreover, even CSF-PRL concentration was higher in HIV-infected patients without cognitive impairment (stage 0 of the clinical classification), (n = 12) in comparison with nonHIV infected controls (n = 6) (mean +/- s.d.; 5.51 +/- 2.31 vs. 3.53 +/- 0.69 x 10(-1) g l-1, respectively; p = 0.028, Mann-Whitney U-test). There was a good correlation between serum and CSF-PRL levels in HIV-infected patients when measured by the Spearman Rank Test (rs = 0.773; p = 0.005). PRL raised serum levels were found in 4 out of 13 patients (30.73%). We conclude that higher levels of CSF-PRL are more frequently found in HIV-infected patients in comparison to uninfected controls. High levels of circulating PRL were also found in HIV-infected patients corroborating results from other work. A good correlation coefficient was found between circulating and CSF-PRL levels in HIV-infected patients, suggesting that disruption of the blood-brain barrier might account for a possible pathogenic mechanism.

AIDS Dementia Complex↗
PubMed1998

BN 52021 (a platelet activating factor-receptor antagonist) decreases alveolar macrophage-mediated lung injury in experimental extrinsic allergic alveolitis.

Several lines of research indirectly suggest that platelet activating factor (PAF) may intervene in the pathogenesis of extrinsic allergic alveolitis (EAA). The specific aim of our study was to evaluate the participation of PAF on macrophage activation during the acute phase of EAA in an experimental model of this disease developed in guinea pigs. Initially we measured the concentration of PAF in bronchoalvedar lavage fluid, blood and lung tissue. In a second phase we evaluate the participation of PAF on alveolar macrophage activation and parenchymal lung injury. The effect of PAF on parenchymal lung injury was evaluated by measuring several lung parenchymatous lesion indices (lung index, bronchoalvedar lavage fluid (BALF) lactic hydrogenase activity and BALF alkaline phosphatase activity) and parameters of systemic response to the challenge (acute phase reagents). We observed that induction of the experimental EAA gave rise to an increase in the concentration of PAF in blood and in lung tissue. The use of the PAF-receptor antagonist BN52021 decreases the release of lysosomal enzymes (beta-glucuronidase and tartrate-sensitive acid phosphatase) to the extracellular environment both in vivo and in vitro. Furthermore, antagonism of the PAF receptors notably decreases pulmonary parenchymatous lesion. These data suggest that lung lesions from acute EAA are partly mediated by local production of PAF.

Alveolitis, Extrinsic Allergic↗
PubMed1998

Double-phase Tc-99m sestamibi scintigraphy in the preoperative location of lesions causing hyperparathyroidism.

Hyperparathyroidism (HPT) is one of the most prevalent endocrine diseases, for which the only effective treatment is surgery. The use of imaging techniques in the preoperative localization of the hyperfunctioning glands is the subject of controversy. The purpose of this paper is to assess the use of double-phase scintigraphy with Tc-99m sestamibi in the localization of lesions causing HPT. We used scintigraphy to preoperatively examine 41 patients, 31 of whom had primary HPT and 10 with secondary HPT. We acquired two anterior view planar images of the neck and chest 10 minutes and 3 hours after injection of Tc-99m sestamibi. Final diagnosis, determined with biopsy, was adenoma in 26 patients, 24 of whom had a positive scintigraphic study (sensitivity 92%), with only two false negative results. In the 14 cases of parathyroid hyperplasia, scintigraphy was also positive, and 62% (30/48) of the excised glands were identified by Tc-99m sestamibi. The radioisotope study was of particular interest in the six patients who previously had undergone surgery, since all the studies were positive; in two patients, additional diseased glands were located in the neck, and an ectopic adenoma was found in the remaining four patients. A fifth ectopic lesion was also sestamibi-positive and, in this case, the scintigraphic result was a direct indication for mediastinal surgery. There were no false positive results, even in patients with multinodular goiter. We conclude that, due to its high sensitivity and the ease with which it is performed, double-phase scintigraphy with Tc-99m sestamibi is the preferred technique for the preoperative localization of diseased glands in patients with HPT, especially in cases of parathyroid adenoma, including those with aberrant location. Its use is of particular interest in patients who previously have undergone surgery.

Adenoma↗
PubMed1998

[Postoperative uptake of Ga-67 in planar scintigraphy and SPECT after median sternotomy].

Surgical alterations after median sternotomy can difficult the interpretation of scintigraphic images with Ga67. To analize the use of Ga67 scintigraphy in this patology, we wanted to know the Ga67 distribution in patients who had suffered median sternotomy. We studied 8 patients in the first month after median sternotomy without infection complication and performed planar images and SPECT. Ga67 showed uptake in liver, spleen and bone. Sternal uptake was greater or lesser than liver uptake but always showed an homogeneous distribution. No mediastinum uptake was observed. Surgical wound showed Ga67 uptake during the first week after sternotomy. To know the < > distribution of Ga67 in patients after median sternotomy allows the scan interpretation when we suspect infectous complications.

Bone and Bones↗
PubMed1998

[Contribution of planar scintigraphy and SPECT with Ga-67 in the diagnosis of infectious complications after median sternotomy].

The prognosis of infections complications after median sternotomy depends of precocious diagnoses and depth extension of infection. We wanted to analyze the use of 67Ga scintigraphy in this pathology, comparing planar studies an SPECT. We studied 22 patients with suspect of infection complication after median sternotomy, the final diagnoses were 5 mediastinitis, 10 osteomyelitis and 7 patients with other pathology. 67Ga scintigraphy diagnosed correctly the 5 mediastinitis, 9 of 10 osteomyelitis and descarted both pathology in the other 7 patients. Planar studies only were able to diagnose correctly 3 of 5 mediastinitis and the another 2 were correctly diagnosed by SPECT. 67Ga scintigraphy is useful in the diagnosis of infection complication after median sternotomy and SPECT is better than planar studies in the diagnosis of mediastinitis.

Diagnosis, Differential↗