Biomedical subjects

R C Silveira

Publications and source records attributed to R C Silveira.

5 recordsLinked to original sources

PubMed2005

Umbilical cord blood and neonatal endothelin-1 levels in preterm newborns with and without respiratory distress syndrome.

Increased pulmonary vascular resistance in preterm newborn infants with respiratory distress syndrome is suggested, and endothelin-1 plays an important role in pulmonary vascular reactivity in newborns. We determined umbilical cord blood and neonatal (second sample) levels of endothelin-1 in 18 preterm newborns with respiratory distress syndrome who had no clinical or echocardiographic diagnosis of pulmonary hypertension and 22 without respiratory distress syndrome (gestational ages: 31.4 +/- 1.6 and 29.3 +/- 2.3 weeks, respectively). Umbilical cord blood and a second blood sample taken 18 to 40 h after birth were used for endothelin-1 determination by enzyme immunoassay. Median umbilical cord blood endothelin-1 levels were similar in both groups (control: 10.9 and respiratory distress syndrome: 11.4 pg/mL) and were significantly higher than in the second sample (control: 1.7 pg/mL and respiratory distress syndrome: 3.5 pg/mL, P < 0.001 for both groups). Median endothelin-1 levels in the second sample were significantly higher in children with respiratory distress syndrome than in control infants (P < 0.001). There were significant positive correlations between second sample endothelin-1 and Score for Neonatal Acute Physiology and Perinatal Extension II (r = 0.36, P = 0.02), and duration of mechanical ventilation (r = 0.64, P = 0.02). A slower decline of endothelin-1 from birth to 40 h of life was observed in newborns with respiratory distress syndrome when compared to controls. A significant correlation between neonatal endothelin-1 levels and some illness-severity signs suggests that endothelin-1 plays a role in the natural course of respiratory distress syndrome in preterm newborns.

Analysis of Variance↗

PubMed2001

[Hypoxic-ischemic syndrome]

OBJECTIVE: To review the literature on the hypoxic-ischemic syndrome, emphasizing its physiopathology, clinical manifestations, and treatment. SOURCES: Electronic search in the Medline and LILACS databases, with selection of the most relevant articles. SUMMARY OF THE FINDINGS: The hypoxic-ischemic syndrome is a multisystem disease with generalized manifestations. The physiopathology is based on hypoxic-ischemic brain injury and reperfusion with cellular injury caused by failure of ATP production secondary to ischemia, and overproduction of oxidative substances caused by reperfusion. Neurological, cardiovascular, respiratory, metabolic, gastrointestinal, renal, and hematological manifestations are frequent. Multisystem clinical management is complex; the neuroprotective approach is still experimental; and the prognosis is not good for those patients with severe hypoxic-ischemic encephalopathy. CONCLUSIONS: The management of the hypoxic-ischemic syndrome is a great challenge to pediatricians., since treatment requires multisystem intervention.

Journal Article↗

PubMed1999

Evaluation of interleukin-6, tumour necrosis factor-alpha and interleukin-1beta for early diagnosis of neonatal sepsis.

The objective of this study was to assess the contribution of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) to an early diagnosis of early-onset neonatal sepsis. A cohort of 117 newborn infants delivered during a 1-y period had IL-6, TNF-alpha and IL-1beta, blood and cerebrospinal fluid (CSF) cultures, leucocyte and platelet count collected on the initial evaluation of possible early-onset sepsis. They were divided into four groups: I, positive blood and/or CSF cultures; II, probably infected with clinical sepsis but negative cultures; III, same as group II but mother received antibiotic antepartum; and IV, newborn infants that did not receive any antibiotic therapy. There were no differences among the four groups with respect to mean gestational ages and birthweights, median Apgar scores, type of delivery, or number of newborn infants with leucocyte count <5000 mm(-3) or >25000 mm(-3), platelet count <100000 mm(-3), immature/total neutrophil ratio >0.2, absolute neutrophil count <1000mm(-3) and median IL-1beta levels. Median IL-6 and TNF-alpha levels were significantly higher in groups with patients with a diagnosis of clinical sepsis than in controls. The optimal cut-off point was 32 pg ml(-1) for IL-6 and 12 pg ml(-1) for TNF-alpha. The combination of both provided a sensitivity of 98.5%. In conclusion, the combination of IL-6 and TNF-alpha is a highly sensitive marker of sepsis in the immediate postnatal period.

Age Factors↗

PubMed1999

[Neonatal sepsis: diagnosis and treatment]

OBJECTIVE: Review the literature on diagnosis and treatment of neonatal sepsis. METHODS: The most important articles on neonatal sepsis were selected through MEDLINE. RESULTS: The present review analyzes the different methods of diagnosis, laboratory and clinical, as well as the different therapeutic managements of neonatal sepsis. CONCLUSION: Neonatal sepsis is a severe disease that must be diagnosed early and properly treated in order to avoid lethal outcome.

Journal Article↗

PubMedDate not supplied

[Plasmatic levels of interleukin-1beta and interleukin-6 in newborn infants with fever]

OBJECTIVE: To study plasma levels of IL-1beta and IL-6 in order to distinguish the presence of bacterial infection in newborn infants with fever. METHODS: A cohort of 117 newborn infants with postnatal age equal to or less than 5 days, with no previous use of antibiotic therapy, and with clinical suspicion of bacterial infection was studied from July 1995 through August 1996. Those with definite criteria for sepsis were considered infected. Fever was defined as axillar temperature > 37.5 degrees C in three independent measurements. The patients were classified in four different groups: Group 1: infected with fever; Group 2: infected without fever; Group 3: not infected with fever; Group 4: not infected without fever. Complete blood count, platelet count, blood or other fluid cultures, and plasmatic levels of IL-1beta and IL-6 were collected before the beginning of antibiotic therapy. RESULTS: Of the 117 newborn infants studied were 66 infected and 51 not infected. Fever was present in 45 (38.46%). The median values of IL-1beta and IL-6 were significantly higher in newborn infants with fever than in those with no fever. There were significant differences between groups 1 and 2, 1 and 4, and 2 and 3 for IL-1beta. There were no significant differences between groups 2 and 4, and 1 and 3 for IL-1beta. Eight (72%) newborn infants with no infection and no fever had environment heating, and 3 had dehydration. There were no differences in median IL-6 levels between groups 1 and 2, and 3 and 4. There were significant differences in the median IL-6 levels between groups 1 and 3, and 1 and 4. CONCLUSIONS: IL- 6 is a marker of early neonatal sepsis. IL-1beta is related to neonatal fever response independently of the presence of bacterial infection.

Journal Article↗