Biomedical subjects

L Sirota

Publications and source records attributed to L Sirota.

At least 19 recordsLinked to original sources

PubMed2006

Bronchopulmonary dysplasia in very low birth weight infants is associated with prolonged hospital stay.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is associated with prolonged hospital length of stay (LOS) and delayed discharge home. OBJECTIVES: To evaluate the association between BPD and LOS and to assess the contribution of concomitant major morbidities on LOS among infants with BPD. STUDY DESIGN: A population-based observational study of very low birth weight (VLBW) infants born from 1995 through 2003. Multivariate analyses, adjusted for perinatal variables, assessed the association between BPD and concomitant morbidities on LOS. RESULTS: Of 10 134 survivors, 1926 (19.0%) had BPD. The adjusted LOS for infants with and without BPD was 84.1 days (95% CI, 82.8, 85.6) and 58.1 days (95% CI, 57.2, 59.0), respectively. Addition of a single concomitant morbidity increased mean LOS by 4 to 13 days. CONCLUSIONS: BPD is a major cause of increased length of hospitalization among VLBW infants. Preventive or therapeutic modalities are required to reduce the significant burden of this condition.

Bronchopulmonary Dysplasia↗

PubMed2005

Spread of vaccine-derived poliovirus from a paralytic case in an immunodeficient child: an insight into the natural evolution of oral polio vaccine.

Sabin strains used in the manufacture of oral polio vaccine (OPV) replicate in the human organism and can give rise to vaccine-derived polioviruses. The increased neurovirulence of vaccine derivatives has been known since the beginning of OPV use, but their ability to establish circulation in communities has been recognized only recently during the latest stages of the polio eradication campaign. This important observation called for studies of their emergence and evolution as well as extensive surveillance to determine the scope of this phenomenon. Here, we present the results of a study of vaccine-derived isolates from an immunocompromised poliomyelitis patient, the contacts, and the local sewage. All isolates were identified as closely related and slightly evolved vaccine derivatives with a recombinant type 2/type 1 genome. The strains also shared several amino acid substitutions including a mutation in the VP1 protein that was previously shown to be associated with the loss of attenuation. Another mutation in the VP3 protein resulted in altered immunological properties of the isolates, possibly facilitating virus spread in immunized populations. The patterns and rates of the accumulation of synonymous mutations in isolates collected from the patient over the extended period of excretion suggest either a substantially nonuniform rate of mutagenesis throughout the genome, or, more likely, the strains may have been intratypic recombinants between coevolving derivatives with different degrees of divergence from the vaccine parent. This study provides insight into the early stages of the establishment of circulation by runaway vaccine strains.

Evolution, Molecular↗

PubMed2004

Nitric oxide levels in preterm and term infants and in premature infants with bacteremia.

OBJECTIVE: To determine the serum nitric oxide levels in healthy neonates and in infants with bacteremia. METHODS: We performed a prospective study in a tertiary neonatal intensive care unit. The serum nitric oxide levels were measured in all infants at birth (basal) and in the infected neonates also on the first 2 days of bacteremia. RESULTS: Thirty-three neonates (10 term, 23 preterm) were included. Eleven preterm infants (mean gestational age 27 weeks) had bacteremia. The main blood culture isolates included coagulase-negative staphylococci (n=4), Klebsiella pneumoniae (n=3), and Escherichia coli (n=3). The serum nitric oxide levels increased during infection in 10 infants (p <0.008). The mean nitric oxide level before infection was 44 microM and during infection 96 microM (p=0.008). In the healthy babies, the mean nitric oxide level was 26 microM in those with a gestational age <27 weeks, 44 microM in those born between 28 and 36 weeks of gestation, and 63 microM in term infants. CONCLUSIONS: Bacteremic preterm infants produce significantly higher amounts of nitric oxide. The basal nitric oxide levels at birth may be correlated with gestational age.

Bacteremia↗

PubMed2004

Risk factors associated with candidaemia in the neonatal intensive care unit: a case-control study.

The incidence of candidaemia is steadily increasing in neonatal intensive care units (NICUs). Several neonatal risk factors for candidaemia have been identified, however, the number of cases in controlled studies is small and knowledge concerning maternal and perinatal risk factors is limited. The present study attempted to identify modifiable, independent maternal, perinatal and neonatal risk factors for candidaemia using a retrospective case-control study in the NICU of a tertiary-care paediatric medical centre. The study group consisted of 56 neonates admitted to the NICU between 1996 and 2000 who acquired candidaemia. The control group comprised the first infant admitted immediately after each study infant matched for gestational age (+/-10 days) and birthweight (+/-200 g). Potential maternal, perinatal and neonatal risk factors were compared between the groups using statistical methods and analysed by univariate and multivariate stepwise logistic regression models. The independent risk factors found to be significantly associated with increased risk of candidaemia were duration of ventilation and presence of bacteraemia before candidaemia. Maternal steroids had a significant protective effect. The positive predictive value using these three parameters was 78.38%. Maximizing in-utero steroid treatment in high-risk pregnancies, minimizing the days of mechanical ventilation and investment of efforts in prevention of bacteraemia may help to reduce the incidence of candidaemia in the NICU.

Analysis of Variance↗

PubMed2004

Effect of radiant warmer on transepidermal water loss (TEWL) and skin hydration in preterm infants.

OBJECTIVE: To evaluate the effect of radiant warmers on skin barrier function in preterm infants. METHODOLOGY: Transepidermal water loss (TEWL) and stratum corneum hydration were measured in 30 preterm infants (birth weight 825 to 2220 g) in seven body areas: forehead, upper back, cubital fossa, palms, soles, abdomen, and inguinal region. Measurements were performed under radiant warmer and incubator conditions. Each patient served as his/her control. RESULTS: TEWL was significantly higher in the radiant warmer compared to the incubator condition in only two areas: forehead and back. The overall mean difference in percentage TEWL between the conditions was 15%. Stratum corneum hydration was not affected by the radiant warmer. CONCLUSIONS: The use of radiant warmers does not significantly decrease barrier function in the preterm infant.

Body Water↗

PubMed2004

Disinfection with 10% povidone-iodine versus 0.5% chlorhexidine gluconate in 70% isopropanol in the neonatal intensive care unit.

AIM: The finding that 10% povidone-iodine skin disinfectant may compromise thyroid function in premature infants prompted its replacement with 0.5% chlorhexidine gluconate solution in 70% isopropanol. The objective of this study was to compare the incidence rates of true infection and contamination associated with the use of these two disinfectants in the neonatal intensive care unit. METHODS: The study population comprised two cohorts of infants admitted to our neonatal intensive care unit: 1) in 1992-1993 when only 10% povidone-iodine was used as a skin disinfectant, and 2) in 1995-1996 when only 0.5% chlorhexidine gluconate solution in 70% isopropanol was used. A retrospective chart review was conducted to determine whether all documented positive blood, CSF and suprapubic aspirate cultures indicated true infection or contamination. True infection was defined as clinical symptoms and/or laboratory abnormalities suggestive of sepsis, with positive blood, CSF or suprapubic aspirate cultures. RESULTS: 1146 infants were admitted during the study periods, 507 during the first period and 639 during the second. In the early group, 17.6% of infants had major malformations, 72.0% were premature and 25.2% had weights of < 1500 g. Corresponding percentages for the latter group were 16.0%, 80.6% and 32.9%, respectively. No statistically significant differences were found between the two research periods in rate of infants with positive blood cultures, true infections, or contamination. CONCLUSION: The use of 0.5% chlorhexidine gluconate solution in 70% isopropanol as a skin disinfectant is justified in neonatal intensive care units because it is not associated with an increased incidence of infections as opposed to 10% povidone-iodine and is devoid of detrimental effects.

Anti-Infective Agents, Local↗

PubMed2004

Keratometry measurements in preterm and full term newborn infants.

AIM: To evaluate the relation between postconceptional age and birth weight with keratometric values in preterm and full term infants. METHODS: A prospective cross sectional study was performed. The cohort included 99 infants (198 eyes) admitted to the Neonatal and Neonatal Intensive Care Units at Schneider Children's Medical Center of Israel from February to September 2002. Keratometry in the horizontal and vertical meridians was performed in both eyes of each infant by two ophthalmologists using an autokeratometer. The results were evaluated according to: postconceptual age (<32 weeks, 32-36 weeks, >36 weeks) and birth weight (<1500 g, 1501-2500 g, >2501 g). RESULTS: Corneal curvature measurements decreased progressively with both postconceptual age and birth weight. At <32 weeks, mean (standard deviation) readings were 63.3 (3.2) diopters (D) for the horizontal meridian and 57.3 (2.6) D for the vertical meridian; corresponding values at >36 weeks were 54.0 (3.0) D and 50.7 (2.4) D. In the <1500 g group, mean (SD) readings were 61.3 (3.9) D for the horizontal meridian and 56.0 (2.9) D for the vertical meridian; corresponding values in the >2501 g group were 51.3 (2.1) D and 48.6 (1.8) D. CONCLUSIONS: There is an inverse relation of horizontal and vertical keratometric values with both postconceptional age and birth weight. Highest readings were noted in the babies with the lowest birth weight and youngest postconceptional age. The decrease in corneal dioptric power to normal values is linear and is apparently part of the normal ocular maturation.

Birth Weight↗

PubMed2003

Association between IL-1ra gene polymorphism and premature delivery.

IL-1 receptor antagonist (IL-1ra) gene polymorphism was examined in 95 Israeli preterm newborns and compared to that of adult volunteers. The genotype was determined using PCR amplification of the variable region of intron 2 of the IL-1ra gene. The IL-1raA1 allele was found to be predominant in the two groups. However, a significant higher frequency of IL-1raA2 allele was found in preterm newborns. The difference was mainly due to higher proportion of homozygous for IL-1raA2 in the preterm neonates (19%) as compared with adults (7%). No such association could be demonstrated between IL-1raA2 allele and severe sepsis in preterm newborns. The frequency of IL-1raA2 allele among preterms with a septic episode did not differ significantly from that found in newborns without sepsis. The results suggest an association between the IL-1ra genotype and the incidence of premature delivery.

Adult↗

PubMed2003

Faecal elastase 1 levels in premature and full term infants.

BACKGROUND: Determination of faecal elastase 1 (FE1) is a simple, relatively inexpensive, non-invasive, highly specific and sensitive test for determining pancreatic function. Secretion of pancreatic enzymes varies during infancy, but there are almost no specific data on the ontogeny of elastase 1 in human babies. AIM: To study FE1 levels in preterm and term babies, and to determine the possible effect of gestational and postconceptual age on these levels. METHODS: Serial stool samples were collected and tested for FE1 level from 77 premature and full term infants. FE1 levels were determined by a commercially available enzyme linked immunosorbent assay (ELISA) kit. RESULTS: A total of 232 stool samples were collected from 77 neonates. The FE1 level measured in the first stool sample (meconium) was below normal (200 micro g/g stool) in all samples regardless of gestational age. Sixty three neonates had at least two samples tested for FE1 level. The mean (SD) level of FE1 in sample 1 was 45.9 (51.1) micro g/g stool and was significantly (p < 0.001) lower than in sample 2 (243.0 (164.9) micro g/g stool). The lower the gestational age of the newborn, the more time it took for FE1 to reach normal levels. CONCLUSIONS: FE1 levels in meconium are low, and studies in meconium should be avoided if pancreatic sufficiency is to be determined. FE1 reaches normal levels by day 3 in term newborns and by 2 weeks in infants born before 28 weeks gestation. Normal levels are reached sooner in infants of more advanced gestational age who start enteral feeding earlier.

Aging↗

PubMed2003

Neonatologists are using much less dexamethasone.

Two historical cohorts (1993-1994 and 2001) of preterm infants ventilated for respiratory distress syndrome were compared. Dexamethasone administration fell from 22% to 6%. Chronic lung disease in survivors rose slightly from 13% to 17%, and mortality fell from 21% to 15% (other causes). The effect of restriction of dexamethasone use on chronic lung disease and mortality remains to be seen.

Birth Weight↗

PubMed2002

Hepatitis B vaccination: long-term follow-up of the immune response of preterm infants and comparison of two vaccination protocols.

BACKGROUND: We conducted a 3-year follow-up study of long-term antibody persistence following vaccination of low-risk preterm infants with recombinant hepatitis B vaccine (HBV). Two three-dose protocols were compared: vaccination beginning within 24 h of birth to initial vaccination delayed until a weight of 2,000 g was reached. SUBJECTS AND METHODS: The study population included 136 children, divided into three groups: children born prematurely (< or = 35 weeks, n = 57), children born at term (> or = 37 weeks, n = 39), both groups receiving the first dose of HBV within 24 h of birth, and children born prematurely (< or = 35 weeks, n = 40), who received the first dose of HBV when a weight of 2,000 g was reached. All infants received the second hepatitis vaccination 1 month after the first, and the third dose 6 months after the first. Hepatitis B surface antibody (AntiHBs) was measured at an age of 3-3.5 years (at least 2.5 years after completion of the three-dose HBV series). An AntiHBs level of > or = 10 IU/l was considered positive. RESULTS: At 3-3.5 years of age, a higher percentage of the premature-delayed vaccination group had a positive AntiHBs level (92.5%) compared to both the premature (54.4%, p < 0.001) and full-term groups (71.8%, p < 0.05) vaccinated soon after birth. The premature-delayed vaccination group also had a significantly higher geometric mean concentration (GMC) (119 vs 14.2 IU/l, p < 0.001 and 119 vs 32.7 IU/l, p < 0.005, respectively). CONCLUSION: Delaying vaccination of premature infants against hepatitis B until a weight of 2,000 g was reached resulted in both a significantly higher percentage of children with positive antibody levels and a significantly higher GMC at 3-3.5 years of age as compared to early-vaccinated preterm and full-term infants. The known short-term advantage of delayed vaccination of preterm infants was shown to persist for at least the first 3 years of life.

Age Factors↗

PubMed2002

Comparative outcome study between triplet and singleton preterm newborns.

AIM: To evaluate the outcome of triplet versus singleton preterm newborns. METHODS: The study population included 64 sets of preterm triplet (gestational age 25-34 wk) and 64 singleton controls. Data on prenatal and perinatal findings, neonatal complications, duration of hospitalization, and neonatal mortality were collected by chart review. RESULTS: Mothers of triplets were more likely to receive prenatal tocolytic treatment and more antenatal steroids for foetal lung maturation, and to be delivered by caesarean section. No differences were found between the groups in perinatal parameters (cord pH, Apgar score, respiratory support after birth), respiratory parameters (severity of acute and chronic lung disease, use and duration of oxygen treatment and assisted ventilation), or neonatal complications (patent ductus arteriosus, intraventricular haemorrhage, periventricular leukomalacia, necrotizing enterocolitis, retinopathy of prematurity, meningitis, sepsis and jaundice). This was also true for duration of hospitalization and neonatal mortality. No differences were recorded by birth order among the triplets for any of these parameters. CONCLUSION: The study indicates that good prenatal care can lead to a good outcome for preterm triplets, close to that of preterm singleton infants. Families and physicians should consider this information when foetal reduction is offered.

Female↗

PubMed2002

Deposition of whole blood platelets on extracellular matrix under flow conditions in preterm infants.

BACKGROUND: A previous study showed greater adhesion by platelets of healthy full term infants to subendothelial extracellular matrix (ECM) under flow conditions compared with healthy adult platelets. AIM: To investigate the adhesion and aggregation of platelets from preterm infants on ECM under defined shear conditions. METHODS: In vitro platelet function was investigated in 106 preterm infants, 74 full term infants, and 26 healthy adults. Blood samples were obtained from all infants within 24 hours of birth, and weekly until discharge from preterm infants only. Citrated whole blood was placed in ECM precoated tissue culture plates and subjected to shear stress (1300 s-1) for two minutes using a rotating Teflon cone. Platelet adhesion (surface coverage) and aggregation (average size) to ECM were assayed using an image analyser. Assays for von Willebrand factor (vWF) antigen, ristocetin cofactor, and vWF collagen-binding activity were performed on samples from an additional 70 preterm infants, 23 healthy full term infants, and 24 healthy adults. Preterm infants with hyaline membrane disease (HMD) were analysed separately in both cohorts. RESULTS: Platelets from preterm infants displayed significantly less platelet adhesion than those from full term infants but similar aggregation and levels of vWF antigen, ristocetin cofactor, and collagen binding activity. Mean surface coverage was 22.0 (8.4)% for preterm infants with HMD, 28.7 (8.0)% for healthy preterm infants, and 35.7 (7.9)% for full term infants. Surface coverage in the preterm infants correlated with gestational age during the first 24 hours only, and did not reach full term levels during 10 weeks of follow up. CONCLUSION: Platelet adhesion to ECM is significantly poorer in preterm than in full term infants, and poorer in preterm infants with HMD than in healthy preterm infants. Intrinsic platelet properties rather than the concentration or activity of vWF may be responsible for this difference.

Adult↗

PubMed2002

Indomethacin and ibuprofen effect on IL-1ra production by mononuclear cells of preterm newborns and adults.

The in vitro effect of indomethacin (IM) and ibuprofen (IB) on the production of the interleukin-1 receptor antagonist (IL-1ra) by cord blood mononuclear cells (CBMC) from preterm newborns was compared to that of peripheral blood mononuclear cells (PBMC) from adults. Mononuclear cells (MC) were incubated with lipopolysaccharide (LPS) in the absence or presence of various concentrations of IM and IB. The level of IL-1ra in the supernatants was tested by ELISA. The results showed a lower ability of MC from preterm newborns to produce IL-1ra as compared with adult cells, supporting the assumption of neonatal immune cell immaturity. IM at pharmacological concentrations caused inhibition of IL-1ra secretion by PBMC from adults whereas IB suppressed the secretion of IL-1ra at higher concentrations only. At the same concentrations neither drug had an in vitro effect on the production of IL-1ra by CBMC of preterm newborns. In conclusion, the lower ability of CBMC of preterm newborns to produce IL-1ra in response to LPS and the absence of an IM and IB effect on the secretion of this cytokine by these cells as compared with PBMC of adults, suggest an underdevelopment of the immune response in preterm newborns.

Adult↗

PubMed2002

[Retinopathy of prematurity--risk factors].

Retinopathy of prematurity (ROP) was first described by Terry in 1942. ROP is considered a multifactorial disease. Low gestational age, low birth weight and oxygen therapy are recognized as risk factors for this condition. Other risk factors including multigestational pregnancy, white race, sepsis, NEC, BPD, intraventricular hemorrhage, lung maturation, steroid treatment, blood transfusions and light exposure were identified by multiple studies. We aim to review these studies in order to identify the independent risk factors for the development of ROP. The reviewed studies confirm that low birth weight, low gestational age, prolonged oxygen treatment and blood transfusions are statistically significant risk factors for the development of ROP. The incidence of all stages of ROP is similar for Caucasian and black infants, although the occurrence of threshold ROP was found higher in the Caucasian group. No relationship was demonstrated between light exposure and the development of ROP. The studies reviewed show decreased frequency and severity of ROP in neonates of mothers who had received antenatal steroid therapy. The findings concerning the influence of postnatal steroid treatment on the incidence of ROP are controversial.

Black People↗

PubMed2001

Intracranial cavernous hemangioma in a neonate.

Cogenital intracranial hemangioma is rare, and the imaging findings have been described in very few cases. We describe a case of a huge congenital left parietal hemangioma that was diagnosed postnatally by head duplex ultrasonography. Complete surgical resection yielded an excellent outcome.

Brain Neoplasms↗

PubMed2001

Transepidermal water loss and skin hydration in preterm infants during phototherapy.

TEWL and skin hydration was measured in 7 body areas before and during phototherapy in 31 preterm infants (gestational age 25 to 36 weeks). Each patient served as his/her own control. There was a mean increase of 26.4% in TEWL during phototherapy. Most prominent increases were recorded in the cubital fossa (45.9%), groin (36.4%), and back (29%). There were no significant differences in stratum corneum moisture in six of the seven body areas before and during phototherapy. This study provides a better understanding of skin physiology during phototherapy in preterm infants and has important implications for the estimation of fluid replacement.

Body Temperature↗

PubMed2001

Mycetoma of the renal pelvis caused by Fusarium species.

A preterm infant, with posterior urethral valves had a mycetoma of the renal pelvis caused by Fusarium species. Prolonged treatment with amphotericin B alone or with flucytosine failed. Combined surgical drainage and medical therapy resulted in full resolution.

Adult↗