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Biomedical subjects

O Ortiz

Publications and source records attributed to O Ortiz.

At least 19 recordsLinked to original sources
PubMed2005

Bioaccumulation of heavy metals in Dactylis glomerata L. growing in a calcareous soil amended with sewage sludge.

The total and DTPA-extractable concentrations of Pb, Ni, Zn, Cu, Cr and Cd were measured in a calcareous soil amended with different doses of sewage sludge under field conditions. The same metals were also measured in the roots and leaves of Dactylis glomerata at the end of the first vegetative period after the sludge was added. The root concentrations of all the metals were unrelated to their concentrations in the soil. Leaf concentrations of Zn and Cr correlated with total (Zn) and DTPA-extractable (Zn and Cr) concentrations in the soil. DTPA extraction did not appear to be very useful for evaluating the bioavailability of metals in this kind of soil as it gave very low correlation coefficients with leaf content (r = 0.684, P = 0.0049 for Zn and r = 0.557, P = 0.0249 for Cr). Concentrations of Pb, Ni, Cu, and Cd in roots and leaves of Dactylis glomerata were unrelated to the total or DTPA-extractable concentrations in the sludge-amended soil.

Biological Availability↗
PubMed1998

"Alone, I wouldn't have known what to do": a qualitative study on social support during labor and delivery in Mexico.

This article presents some of the most relevant qualitative results of a trial to evaluate the effects of the provision of psychosocial support to first-time mothers during labor, childbirth and in the immediate postpartum period in a social security hospital in Mexico City. The article focuses on the experiences of mothers who have received psychosocial support from a doula (the term doula is used to identify a woman who provides continuous support to a woman during labor. delivery and the immediate postpartum period) and compares them with the experiences of those women who gave birth following normal hospital routine. Sixteen in-depth interviews were held with women in the immediate post partum period (eight of whom had been accompanied by a doula and eight who had not) before they were discharged from hospital, and the results were analyzed using qualitative techniques. The interviews showed that the women accompanied by a doula had a more positive childbirth experience. The differences between both groups related to their perceptions of the childbirth experience; the treatment they received from hospital staff; the information they were given and how well they understood it; their perception of hospital routines; their feelings about cesarean sections and, spatial and temporal perceptions. The most important difference between the two groups was the way they expressed their feelings about their own labor, their sense of control and their self-perception.

Delivery, Obstetric↗
PubMed1998

Clinical and radiologic evaluation of optic pathway lesions.

The clinical evaluation can often suggest the level of a visual pathway lesion; however, several different types of pathological processes, can produce the same visual field deficit. Imaging evaluation with CT and/or MRI can help to localize and characterize these diverse types of pathology. A radiological differential diagnosis can then be suggested which, in turn, facilitates patient management. In certain instances, the specific cause of a visual field defect can be identified with the radiological evaluation.

Brain Diseases↗
PubMed1998

Magnetic resonance imaging of traumatic cervical nerve injuries.

Posttraumatic cervical injuries represent a spectrum of injuries ranging from simple traction to frank nerve root avulsion with meningocele formation. The authors describe 3 patients with cervical nerve injuries, depicted by magnetic resonance imaging, highlighting unusual imaging manifestations.

Accidents, Traffic↗
PubMed1997

Transient enlargement of an intracranial aneurysm during pregnancy: case report.

BACKGROUND: The association of intracranial aneurysm and pregnancy is uncommon. Hemodynamic stress plays an important role in the growth of aneurysms. METHODS: The authors report the case of an enlarging cavernous carotid aneurysm in a pregnant 15-year-old young woman. RESULTS: The aneurysm was initially diagnosed prior to the patient's pregnancy by both cross-sectional imaging and cerebral angiography. Further imaging evaluation was required during pregnancy, which demonstrated significant enlargement of the aneurysm. Following delivery, the lesion decreased in size. CONCLUSIONS: We review potential factors associated with pregnancy that may increase hemodynamic stress and influence aneurysm growth. Additionally, the management of pregnancy-related intracranial aneurysms is discussed.

Adolescent↗
PubMed1997

Contemporary management of cerebrospinal fluid rhinorrhea.

Management of patients with cerebrospinal fluid rhinorrhea (CSF) remains controversial. Most studies recommend either an endoscopic or an external extracranial approach, depending on the surgeon's preference. Eighteen patients with CSF rhinorrhea have been managed at our institution since 1990. The causes of the CSF rhinorrhea consisted of functional endoscopic sinus surgery (7), lateral rhinotomy with excision of a benign nasal tumor (3), spontaneous rhinorrhea (7), and secondary repair after intranasal ethmoidectomy (1). In 11 patients the CSF leak was recognized at the time of surgery; in 10 of these patients it was repaired during the primary surgery, whereas one patient underwent secondary repair after failure of conservative management of his CSF fistula. Seven patients underwent exploration for spontaneous CSF rhinorrhea. Four patients had computer tomography scans that showed the leak, and two patients had cisternography to localize the leak. One patient underwent magnetic resonance cisternography. Both of these leaks were identified with cisternography and were then confirmed intraoperatively. Repair methods included a pedicled septal mucosal flap (4), a free mucosal graft from the septum (7), and a middle turbinate (5). Two patients had obliteration of the sinus with muscle/fascia and fibrin glue. Eight patients were repaired endoscopically. The remainder underwent repair through external approaches. Seventeen patients (at a minimum 1 year follow-up) remain free from leakage. One patient required a second repair 8 months after surgery. Iatrogenic trauma remains the most common cause of CSF rhinorrhea. Management at the initial setting is the least morbid approach and is successful in 95% of cases. Whether an endoscopic or external approach is used depends on surgical expertise and experience.

Adult↗
PubMed1997

Massive osteolysis of the skull and upper cervical spine. Case report and review of the literature.

Massive osteolysis is a type of idiopathic osteolysis in which there is spontaneous onset of bone resorption. Almost any bone in the body can be affected. The authors present the case of a 62-year-old man diagnosed with massive osteolysis of the occipital bone and the upper two cervical vertebrae. Despite extensive pneumocephalus, no neurological sign or spinal instability was evident. In this case 4000 cGy of radiation in 200-cGy fractions was administered to the diseased area while the patient was kept in a Miami-J collar. At the 2-year follow-up examination, arrest of the disease process and new bone formation was evident on radiographic studies.

Cervical Vertebrae↗
PubMed1996

CT-Guided Percutaneous Lateral Suprazygomatic Approach for Posterior Orbital Wall Biopsy.

We describe a computed tomography-(CT) guided percutaneous technique for obtaining a core tissue sample from the bony margin of the orbital apex via a lateral suprazygomatic approach. We found this route to be safe and effective while obviating the need for an open biopsy in a patient presenting with a mass encroaching on the left orbital apex.

Journal Article↗
PubMed1996

Size of the corpus callosum in cerebral palsy.

It has been suggested that the size of the corpus callosum may have diagnostic significance in cerebral palsy, although this relationship is incompletely defined. Ninety-one patients with cerebral palsy had been studied by magnetic resonance imaging in the 5-year period from 1990 to 1994. Fifty-seven of these 91 patients had a technically appropriate midsagittal magnetic resonance image for quantitative morphometric analysis. The ratio of the area of the corpus callosum to the area of the supratentorial brain was compared to published age- and gender-specific norms. Imaging findings were correlated with clinical history and cause of cerebral palsy. The corpus callosum was of normal size in 43 patients and more than 2 standard deviations below the mean in 14 patients. The causes for cerebral palsy included hypoxic ischemic encephalopathy (32), cerebral dysgenesis (8), and porencephalic strokes (6); the etiology could not be established in 11 patients. The size of the corpus callosum was highly correlated with the cause of cerebral palsy, such that all patients with cerebral dysgenesis had hypoplasia of the corpus callosum (one-sided z test, p < 0.0001). Conversely, the callosum was of normal size in 32 of 38 patients with hypoxic ischemic encephalopathy and porencephalic strokes. The presence of a hypoplastic corpus callosum is highly associated with cerebral dysgenesis as a cause for cerebral palsy.

Adolescent↗
PubMed1996

Postoperative magnetic resonance imaging with titanium implants of the thoracic and lumbar spine.

Within recent years, the technologies of radiological imaging and spinal instrumentation have exponentially increased. New methods of preoperative imaging, that is, magnetic resonance imaging (MRI) and computed tomography, have allowed for a better understanding of surgical pathology. Such an understanding is likely to lead to a more successful surgical experience, which certainly is the case with spine surgery with instrumentation. However, after implantation of most instrumentation, imaging is greatly impaired. Metallurgic advancements in titanium were sought to reduce postoperative imaging problems. The purpose of this study is to assess the presence and extent of artifacts seen on postoperative MRI scans in patients with titanium spinal implants. Six patients, four with degenerative spine disease and two with neoplasms, had thoracic and/or lumbar spinal fixation performed with titanium instrumentation. All patients underwent postoperative conventional MRI with the use of T1-weighted, T2-weighted, and gradient-echo sequences. The scans and individual sequences were then analyzed for image quality. A progressive and significant increase in imaging artifact related to the titanium spinal instrumentation was observed on the T1-weighted, T2-weighted, and gradient-echo sequences. Titanium spinal instruments do not allow optimal postoperative imaging on conventional MRI scanners.

Adult↗
PubMed1996

Carotid artery occlusion following a karate punch to the neck.

A 43-year-old corrections officer developed right neck and posterior head pain following a karate punch to the right side of the neck during self-defense training. One week later, he developed an acute left hemiparesis. Magnetic resonance imaging demonstrated a right hemisphere cerebral infarction and absence of signal flow void in the right internal carotid artery. Carotid ultrasound demonstrated complete occlusion of the right internal carotid artery without evidence of atherosclerotic disease. Carotid occlusion with cerebrovascular infarction is a possible complication of martial arts training involving forceful blows to the neck.

Adult↗
PubMed1995

Congenital nasal pyriform aperture (bony inlet) stenosis.

Congenital nasal pyriform aperture stenosis should be considered in the differential diagnosis of infants with nasal airway obstruction. It can occur as an isolated anomaly or it can be associated with other congenital anomalies. A history of cyclical respiratory distress and cyanosis often associated with feeding and relieved by crying is characteristic. On examination, the nasal airway is narrowed anteriorly. CT is the study of choice to make the diagnosis and rule out other causes of nasal obstruction. Conservative management is recommended, sometimes with the use of a McGovern nipple for feeding. Severe cases or those in which conservative management fails should be considered for surgery.

Female↗
PubMed1995

Analysis of breakthrough pain in 50 patients treated with intrathecal morphine infusion therapy. Development of tolerance or infusion system malfunction.

Fifty patients with intractable benign pain were treated with intrathecal morphine (IT-MS) infusion therapy. Median follow-up was 39 months (range 5-70). Breakthrough pain was reported in 45 (90%) patients in 75 outpatient clinic events. A diagnostic algorithm was developed to evaluate and efficiently treat these patients. A programmed bolus (50% of daily dose) identified that 50 (67%) breakthrough events where due to partial tolerance to the IT-MS. Radiographic survey of the catheters identified malfunctions in 11 patients. Attempts to withdraw CSF from the side-port demonstrated obstruction in 7 due to kinking not seen on X-rays. Side-port myelography demonstrated scarring that obstructed the flow of morphine to the spinal cord in 2 patients. Benefits were regained after all surgical catheter corrections. In total, partial tolerance was seen in 23 patients (46%) during 50 (67%) breakthrough events, 15 patients (30%) required 22 catheter revisions during 27% of breakthrough events and 2 patients had progressive disease. True tolerance was encountered in only 5 patients (10%) during 5 (7%) breakthrough pain events.

Adult↗
PubMed1995

Hemangiomas in the calvaria: imaging findings.

Lesions of the skull vault are fairly common; however, they are often difficult to diagnose. By using specific imaging criteria, one may readily diagnose a calvarial hemangioma. These lesions account for 10% of benign primary neoplasms of the skull [1]. This essay illustrates the spectrum of imaging findings seen on plain radiography, CT, MR imaging, and angiography for patients with calvarial hemangiomas.

Adult↗