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Biomedical subjects

F Cabañas

Publications and source records attributed to F Cabañas.

At least 19 recordsLinked to original sources
PubMed2006

Cerebrospinal fluid leucocyte counts in healthy neonates.

OBJECTIVES: To determine the cerebrospinal fluid (CSF) white blood cell (WBC) count of normal term neonates, and compare the CSF WBC profile of normal and symptomatic infants without infection of the central nervous system (CNS). METHOD: Neonates were included if (a) they were at risk of congenital Toxoplasma infection and had undergone a lumbar puncture to assess CNS involvement, and (b) serial specific serum IgG and IgM determinations had ruled out congenital infection. According to neonatal chart reviews, 30 consecutive patients without CNS infection were classified as normal (absolutely asymptomatic) or symptomatic (any kind of symptoms). RESULTS: CSF WBC count was higher in 11 symptomatic (7/mm(3), 0-30/mm(3)) than in 19 normal (1/mm(3), 0-5/mm(3)) neonates (p<0.01). CONCLUSION: Normal neonatal CSF contains up to 5 WBCs/mm(3). Mild pleocytosis can be found in symptomatic infants without CNS infection.

Humans↗
PubMed2001

Postnatal adaptation of brain circulation in preterm infants.

Global and regional postnatal cerebral circulatory changes in stable preterm infants were studied, and their relation to brain injury was assessed. Thirty-five preterm infants were studied on the first and second days of age. Cerebral blood flow (CBF) (mL/hg per min) and cerebral blood volume (CBV) (mL/hg) were measured using near-infrared spectroscopy. The cerebral blood flow velocity (cm/second) (peak systolic, diastolic flow, mean flow) and resistance index (RI) were determined in the internal carotid, anterior cerebral, and striate arteries by color Doppler flow imaging. Serial cerebral ultrasound studies were performed to detect changes in brain parenchymal echogenicity or intraventricular hemorrhage (IVH); the maximum severity of these findings was considered. CBF and cerebral blood flow velocity increased significantly with time, and such changes were independent of mean blood pressure, PO(2), PCO(2), hematocrit, or glycemia. In contrast, CBV and RI remained unchanged. According to the results of sonograms, no differences were found in postnatal CBF and cerebral blood flow velocity changes, regardless of whether patients had or did not have parenchymal lesions or IVH. However, higher CBV values were found on the second day in infants with IVH compared with infants without IVH. Early coupling of CBF and metabolic demands is independent of blood pressure. Improved venous return, instead of vasodilation, could be important in this adaptation.

Adaptation, Physiological↗
PubMed1999

Effect of the cyclo-oxygenase blocker ibuprofen on cerebral blood volume and cerebral blood flow during normocarbia and hypercarbia in newborn piglets.

Indomethacin modifies baseline cerebral haemodynamics and metabolism, as well as vasomotor adaptive responses. However, the significance of arachidonic acid metabolites in the regulation of cerebral circulation remains unclear. A study was made of the effect of inhibition of the cyclo-oxygenase pathway on baseline cerebral haemodynamics and CO2-induced vasodilation using the more specific cyclo-oxygenase blocker ibuprofen in a neonatal pig model. Two methods were used: radiolabelled microspheres to measure cerebral blood flow and near infrared spectroscopy to calculate absolute changes in cerebral blood volume. The relationship between CO2-induced changes in these two haemodynamic parameters was evaluated. Fifteen newborn piglets <7 d old received an i.v. infusion of either ibuprofen (30 mg/kg) (IB group, n = 8) or saline (control group, n = 7). Cerebral blood flow and absolute changes in cerebral blood volume were measured while the piglets were breathing room air at baseline and 30 min after infusion of ibuprofen or saline, and 15 min and 30 min after inducing hypercarbia. Global and regional cerebral blood flow (ml/hg/min) and absolute changes in cerebral blood volume (ml/hg) did not vary between baseline and 30 min after infusion of ibuprofen or saline. During hypercarbia, global and regional cerebral blood flow and absolute changes in cerebral blood volume increased significantly in both the ibuprofen and control groups (p < 0.01). The mean percentage increases in blood flow and blood volume at each measurement were almost identical, with approximately 90% of the increase in both parameters occurring after 15 min of hypercarbia, then reaching a plateau. However, we found no agreement between cerebral blood flow changes and absolute changes in cerebral blood volume. We conclude that ibuprofen did not alter either baseline cerebral circulation or physiological CO2-induced vasodilation in newborn pigs. We speculate that hypercarbic cerebral vasodilation could be caused either by mediators other than the cyclo-oxygenase metabolites of arachidonic acid or by a direct effect on vessel walls.

Analysis of Variance↗
PubMed1998

Cerebral haemodynamics in preterm infants after exposure to dexamethasone.

AIM: To determine changes in brain haemodynamics produced by dexamethasone; to evaluate the pathophysiological conditions involved in the effect of dexamethasone. METHODS: A prospective study was made of 12 ventilated preterm infants who received dexamethasone (0.25 mg/kg/12 hours) for ongoing chronic lung disease or extubation failure. Cerebral blood flow (CBF), absolute cerebral blood volume (CBV), and cerebral blood volume changes (delta CBV) were estimated by near infrared spectroscopy, before and 10, 30, 60, 120, 180 and 240 minutes after the first, third, and fifth doses of dexamethasone. All patients were monitored continuously using pulse oximetry, transcutaneous blood gases, and blood pressure. RESULTS: There were significant short term changes in delta CBV on each day of the study; delta CBV increased significantly at 240 minutes compared with values before the first dose, and from 120 minutes onward during the third and fifth doses. However, mean CBV values averaged over 240 minutes after the first, third, and fifth doses did not vary. Mean CBF values averaged over 240 minutes increased progressively up to the fifth dose (significant differences between the first and fifth dose). The short term changes in CBF consisted of a significant increase 60 minutes after dexamethasone administration compared with the before and 10 minute values in every study. Blood pressure was significantly higher in the third and fifth doses than in the first dose. Blood pressure showed no short term changes. There was no correlation between CBF and blood pressure changes. TcPCO2 (transcutaneous PCO2) decreased significantly throughout the study period, with the average mean value in the fifth dose significantly lower than in the first dose. Nevertheless, no short term changes in TcPCO2 were observed. CONCLUSIONS: Postnatal systemic dexamethasone administration produced significant changes in cerebral haemodynamics that seemed to be related to both a direct effect on regional vessel walls and the cumulative effect of dexamethasone.

Anti-Inflammatory Agents↗
PubMed1997

Effect of dexamethasone therapy on cerebral and ocular blood flow velocity in premature infants studied by colour Doppler flow imaging.

UNLABELLED: Although dexamethasone (DEX) is used widely in neonates with chronic, and even recently with acute respiratory disease, its potential side-effects on human cerebral and ocular haemodynamics remain unknown. The effects of DEX on cerebral and ocular blood flow velocities were assessed in preterm infants with lung disease and mechanical ventilation. Ten ventilated preterm infants received DEX (0.25 mg/kg/12 h) for ongoing chronic lung disease or extubation failure. Colour Doppler flow imaging studies of the internal carotid, anterior cerebral and ophthalmic arteries were made before and 10, 30, 60, 120 and 240 min after the 1st, 3rd, and 5th doses of DEX. Peak systolic, temporal mean, and end-diastolic flow velocities and the resistance index (RI) of Pourcelot were determined. The brain was examined by ultrasonography before and at the end of each Doppler study. All patients were continuously monitored for transcutaneous blood gases and blood pressure. All flow velocities and the RI of the internal carotid, anterior cerebral and ophthalmic arteries showed a similar trend throughout the study. The means of the values averaged for the 240 min of cerebral and ocular blood flow velocity with each dose were progressively higher and the values of the RI progressively lower up to the 5th dose. The most significant changes occurred in end-diastolic flow velocity and consisted of a percentage increase between the 1st and 5th dose of 72% in the internal carotid artery, 102% in the anterior cerebral artery and 84% in the ophthalmic artery. Changes in arterial blood pressure followed a pattern similar to that of changes in blood flow velocity. CONCLUSIONS: Dexamethasone increments cerebral and ocular blood flow velocity. We speculate that this finding may be relevant to the development of brain and retinal injury.

Analysis of Variance↗
PubMed1997

Interleukin-6 in the cerebrospinal fluid after perinatal asphyxia is related to early and late neurological manifestations.

OBJECTIVES: To investigate if the concentration of interleukin-6 (IL-6) in the cerebrospinal fluid (CSF) is affected by perinatal asphyxia, and to examine the relation of IL-6 levels in the CSF to the severity of hypoxic-ischemic encephalopathy (HIE), to brain damage, and to the neurological outcome. METHODS: Asphyxiated term neonates were included. Cerebrospinal fluid IL-6 was measured by a sensitive enzyme-linked immunosorbent assay. RESULTS: Twenty neonates were studied: 3 had no HIE, 5 had stage 1, 6 had stage 2, and 6 had stage 3. CSF IL-6 levels (8 to 90 hours of life) were higher in neonates with HIE stage 3 (range, 65 to 2250 pg/mL) when compared with neonates with HIE stage 0 to 2 (<2 pg/mL in 12 neonates, 10 pg/mL in 1). According to neuroimaging techniques and/or pathological examination, 14 neonates were normal, and 5 showed signs of brain damage; 1 was not classified. CSF IL-6 levels were significantly higher in neonates with signs of brain damage. Finally, 5 neonates had adverse outcomes (4 died, 1 had cerebral palsy), 2 had mild motor impairment, and 13 had normal outcomes. CSF IL-6 levels were higher in neonates with adverse outcomes (range, 65 to 2250 pg/mL) compared with neonates with favorable outcomes. CONCLUSION: The magnitude of IL-6 response in the CSF after perinatal asphyxia is related to the severity of neonatal HIE, to brain damage, and to the neurological outcome. Our results suggest that IL-6 might play a role in neonatal hypoxic-ischemic brain damage.

Asphyxia Neonatorum↗
PubMed1996

Central nervous system vasculopathy in neonatal lupus erythematosus.

Central nervous system involvement in neonatal lupus erythematosus (NLE) has not been previously reported. We report four patients with NLE, all with complete congenital heart block and three with cerebral ultrasound and color Doppler flow imaging (CDFI) studies demonstrating evidence of associated vasculopathy in the gangliothalamic vasculature. CDFI confirmed blood flow through the affected vessels, indicating that blood flow was not compromised at this early stage. Short-term follow-up revealed no signs of progression of the vasculopathy, focal ischemia, gangliothalamic atrophy, or neurological impairment. Nevertheless, the implications of this finding with respect to the natural history of NLE remain to be defined, particularly in cases in which the disease develops into systemic lupus erythematosus later in life. Besides specific diagnostic studies for NLE, cerebral ultrasound, and CDFI studies are mandatory in all cases of complete congenital heart block, regardless of whether mothers are diagnosed as having connective-tissue disease or not. Neonates with signs of vasculopathy in the gangliothalamic region should be examined for NLE.

Autoantibodies↗
PubMed1995

Multiple organ involvement in perinatal asphyxia.

OBJECTIVES: (1) To evaluate the frequency and spectrum of severity of multisystem dysfunction after perinatal asphyxia and (2) to analyze the relationship between the clinical and biochemical markers of perinatal asphyxia and multiorgan involvement. STUDY DESIGN: Seventy-two consecutive term newborn infants with perinatal asphyxia were studied prospectively. Systematic neurologic, renal, pulmonary, cardiac, and gastrointestinal evaluations were performed. Involvement of each organ was classified as moderate or severe. RESULTS: Involvement of one or more organs occurred in 82% of the infants; the central nervous system (CNS) was most frequently involved (72%). Severe CNS injury (7 infants) always occurred with involvement of other organs, although moderate CNS involvement was isolated in 14 infants. Renal involvement occurred in 42%, pulmonary in 26%, cardiac in 29%, and gastrointestinal in 29% of the infants; 15% neonates had renal failure and 19% had respiratory failure. The Apgar scores at 1 and 5 minutes were the only perinatal factors related to the number of organs involved and the severity of involvement; the Apgar score at 5 minutes had the stronger independent association. No relationship or organ dysfunction was found with the umbilical cord arterial blood pH, meconium-stained amniotic fluid, umbilical cord abnormalities, presentation, or type of delivery. CONCLUSIONS: Our findings indicate that the Apgar score at 5 minutes, in infants who have other criteria for asphyxia, is the perinatal marker that may best identify infants at risk of organ dysfunction.

Apgar Score↗
PubMed1995

Neural migration disorders studied by cerebral ultrasound and colour Doppler flow imaging.

Cerebral ultrasound and colour Doppler flow imaging (CDFI) were used to diagnose a wide spectrum of anomalies of cell migration (17 patients): presumed lissencephaly (n = 12); schizencephaly of both fused (n = 2) and open lips (n = 2); hemimegalencephaly (n = 1); and subependymal type grey matter heterotopia (n = 12). The patients with grey matter heterotopia had irregular ventricular margins (n = 10), periventricular hyperechogenic bands (n = 12), and/or periventricular hyperechogenic nodules (n = 7). Some patients had more than one type of migration disorder as well as other central nervous system malformations. Cerebral ultrasound diagnoses were confirmed by magnetic resonance imaging (MRI) or necropsy. It is concluded that colour Doppler flow imaging is a worthwhile addition to the assessment of brain surface anomalies.

Autopsy↗
PubMed1995

Cerebrospinal fluid beta 2-microglobulin in neonates with central nervous system infections.

Beta 2-microglobulin (beta 2m) determination in CSF of 72 neonates who underwent a spinal tap as part of a sepsis or meningo-encephalitis workup was performed to evaluate the usefulness of this test in the diagnosis of CNS infections. Beta 2m was measured by enzyme immunoassay. Sixty neonates had sterile culture and normal neurological status at discharge. Twelve infants had CNS infections: 8 bacterial meningitis, 3 TORCH infections (T = toxoplasmosis, O = others, R = rubella, C = cytomegalovirus and H = herpes simplex) and 1 viral meningitis. Neonates with CNS infection exhibited significantly higher CSF beta 2m levels compared to neonates with sterile culture (6.24 +/- 2.66 vs 1.74 +/- 0.5 mg/l; P < 0.0001). CSF beta 2m levels did not correlate with the white cell count, total protein concentration or glucose level in CSF. When serum and CSF levels were measured simultaneously, the CSF beta 2m level was significantly higher than the corresponding serum level in patients with CNS infection (6.98 +/- 2.5 vs 3.2 +/- 0.25 mg/l; P < 0.01). Sensitivity, specificity, and predictive values were estimated for different cut-off points. The best operational diagnostic cut-off value was 2.25 mg/l. Receiver operating characteristic curve analysis showed an appropriate trade-off between specificity and sensitivity and indicated that CSF beta 2m was accurate in distinguishing between neonates with and without CNS infection. Conclusion. CSF beta 2m may be a useful ancillary tool in neonates when CNS infection is suspected.

Female↗
PubMed1994

New pattern of hyperechogenicity in thalamus and basal ganglia studied by color Doppler flow imaging.

Thirty-seven infants whose cerebral real-time B-mode ultrasound (CUS) documented hyperechogenic areas in the thalamus and basal ganglia (HTBG) either of linear or fine punctate pattern, were studied prospectively by color Doppler imaging (CDI). This study aimed to establish a relationship between these areas and the regional vasculature, to analyze associated disorders to establish pathogenesis, and to determine clinical significance. HTBG were diagnosed in the first 4 days of life in all but 7 infants. Different patterns of HTBG were observed: punctate in 11 infants, linear in 12, and mixed in 14. The basal ganglia were affected in all patients, 9 also had involvement of the thalamus. CDI confirmed that HTBG were allocated along the gangliothalamic vessels. Blood flow velocity waves were obtained at this level in all patients. Real-time spectral analyses were performed in 35 patients and compared with a control group of 20 healthy neonates. Differences were not significant. Computed tomography and magnetic resonance imaging failed to indicate this abnormality. Necropsy revealed basophilic deposits in the walls of involved arteries. Congenital infections manifested in 5 patients, chromosomal abnormality in 1, dysmorphic syndromes in 9 (3 unidentified), isolated congenital defects in 5, and diverse congenital disorders in 3. In the remaining 14, no congenital disorders nor infections were found. This CDI study demonstrates the vascular location of these HTBG. Supported by early CUS diagnosis, it is speculated that vascular injury in that region has a prenatal origin. This abnormality does not appear to alter regional blood flow. HTBG are associated with very heterogeneous disorders and in most patients the etiology and pathogenesis remain unclear.

Arteries↗
PubMed1994

Neuron-specific enolase and myelin basic protein: relationship of cerebrospinal fluid concentrations to the neurologic condition of asphyxiated full-term infants.

OBJECTIVE: We questioned whether neuron-specific enolase (NSE) and myelin basic protein (MBP) concentrations in cerebrospinal fluid (CSF) in the first 72 hours of life are correlated with the neurologic condition of asphyxiated full-term infants in the neonatal period and at 1 year of age. PATIENTS AND METHODS: Sixty-nine asphyxiated infants were studied with serial neurologic examination, cranial ultrasonography, and neurologic follow-up. CSF samples were obtained by lumbar puncture at 12 and 72 hours of life. NSE was measured by enzyme immunoassay, and MBP was measured by radioimmunoassay. RESULTS: Twenty infants had no neonatal encephalopathy and 49 exhibited different stages of encephalopathy. NSE and MBP concentrations in CSF at 12 and 72 hours of life were related to the degree of neonatal encephalopathy. Neither NSE nor MBP levels were correlated with any perinatal factors. Infants with documented brain injury had the highest concentrations of both NSE and MBP. The concentrations of these two biochemical markers at both 12 and 72 hours correlated with adverse outcome (death or cerebral palsy at 1 year). Based on a receiver operating characteristics curve analysis for any given specificity, NSE at 12 hours was a more accurate marker than MBP at either 12 or 72 hours for distinguishing infants with motor impairment at age 1 year from infants with normal outcome at the same age. CONCLUSIONS: Our findings suggest that NSE and MBP are reliable biochemical markers for early estimates of hypoxic-ischemic brain damage in asphyctic full-term newborns, NSE being superior to MBP.

Asphyxia Neonatorum↗
PubMed1992

Early neurological manifestations and brain anomalies in Marden-Walker syndrome.

We report on an infant with the Marden-Walker syndrome. In addition to the consistent neurological abnormalities described previously in this syndrome, the infant had a striking neurological constellation, absence of primitive reflexes, jerky eye movements, failure to habituate to repeated stimuli, inadequate behavior development, and absence of orientation responses to visual or auditory stimuli. Muscle biopsy showed a similar pattern to the congenital fiber-type disproportion. Ultrasonograms and magnetic resonance imaging of his brain demonstrated absence of corpus callosum, colpocephaly, hypoplastic brainstem, hypoplasia of the inferior vermis and of the cerebellar hemispheres. These findings further delineate this syndrome and suggest that prenatal central nervous system (CNS) dysfunction, mainly of the cerebellum and brainstem, may play a significant role in the pathogenesis of the Marden-Walker syndrome.

Abnormalities, Multiple↗
PubMed1992

Stroke in neonates with cardiac right-to-left shunt.

Neonatal focal cerebral arterial infarction has been rarely reported in the literature, in contrast to the watershed infarctions, which are common entities among asphyxiated infants. In neonatal postmortem series, thromboembolism was the commonest cause of cerebral arterial occlusion; the source of emboli was associated to different risk factors. Our four cases are the first alive patients reported with congenital heart disease and right-to-left shunt, who suffered a cerebral infarct with its clinical neurological correlates in the neonatal period. We assume that the most probable mechanism was paradoxical embolism, once pulmonary filter is obviated as a result of the altered hemodynamics in these patients. Our data demonstrate the value of ultrasound scanning for assessment of focal cerebral ischemic lesions. Thus, although abnormal neurological signs in this particular group of infants could be attributed to hypoxemia or specific treatments as prostaglandins, we suggest routine cerebral ultrasounds in neonates with congenital heart disease and neurological disabilities, as early complications could be not so infrequent.

Cerebrovascular Disorders↗
PubMedDate not supplied

Ultrasonographic findings in thalamus and basal ganglia in term asphyxiated infants.

Three severely asphyxiated term neonates demonstrated bilateral hyperechogenicity in the thalamus and basal ganglia. During evolution, areas of attenuated echogenicity appeared in these structures at the same time as periventricular cysts were evident in 2 patients with coexistent periventricular leukomalacia. All 3 patients developed ventricular dilatation; in the 2 patients with periventricular leukomalacia, the ventricular border was irregular in the outer (dorsal) margin, and interhemispheric fissures were widened as a manifestation of cerebral atrophy. Furthermore, the thalamic inner (ventral) margins of the lateral ventricles were irregular in all 3 patients. This previously unrecognized finding points to a particular form of cerebral atrophy localized in the gangliothalamic region that contributes to the development of ventriculomegaly. The reported sonographic sequence implies profound damage in the thalamus and basal ganglia in asphyxiated infants which undoubtedly has contributed to the poor outcomes of our patients.

Asphyxia Neonatorum↗
PubMedDate not supplied

Cerebral abnormalities in congenital myotonic dystrophy.

The brain structure of 14 infants born with congenital myotonic dystrophy at 2 hospitals was evaluated by cranial ultrasonography, and the findings were correlated with clinical and neuropathologic data. Ventricular dilation was diagnosed in 11 infants (78%). Seven infants died during the neonatal period; all had ventricular dilation which remained essentially static. In the ultrasound scans of the 5 infants with ventricular dilation. Of the 7 survivors, 4 had ventricular dilation born at 1 hospital, 4 had widening of the interhemispheric fissure. Macrocephaly, a previously unrecognized finding in congenital myotonic dystrophy, was present in 10 infants (71%), 8 of whom presented with ventricular dilation. None had clinical evidence of increased intracranial pressure. There was no ventricular obstruction in the 4 brains examined pathologically. Histologic examination revealed minor expression of neuronal migrational disturbances in each patient. Macrocephaly together with the ultrasonographic and neuropathologic findings in our patients suggest that these abnormalities may originate in an external hydrocephalus.

Brain↗