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R D Christensen

Publications and source records attributed to R D Christensen.

At least 19 recordsLinked to original sources
PubMed2007

Hematological abnormalities during the first week of life among neonates with Down syndrome: data from a multihospital healthcare system.

Various hematological abnormalities have been reported among neonates with Down syndrome. Thrombocytosis, thrombocytopenia, polycythemia, neutrophilia, transient myeloproliferative disorder (TMD), and congenital leukemia have all been reported. The two largest case series previously reported involved 63 and 31 cases. To acquire hematological data from a larger case series, we obtained all CBCs done during the first week after birth on all neonates with Down syndrome cared for in an Intermountain Healthcare (IHC) hospital with a date of birth between January 1, 2001 and December 31, 2005. During this period, 145,522 live births were recorded at 18 hospitals. Down syndrome was recognized in 226 (1 in 644). One hundred fifty-eight (70%) of these had one or more CBCs obtained before the seventh day (144 hr). Neonates who did versus did not have a CBC in the first week had a similar gestational age, birth weight, percentage who were LGA and SGA, and length of stay. Neutrophilia was the most common hematological abnormality detected, with 80% of absolute neutrophil counts above the upper limit of normal for age. Six percent (9/158) had blasts identified on the blood film and three, where this was persistent, were referred to the pediatric hematology service for further evaluation. The next most commonly detected abnormality was thrombocytopenia, with 66% of platelet counts <150,000/microl, and with 6% of counts <50,000/microl. The mean platelet volume did not correlate with the platelet count, but tended to run slightly large (9.2 +/- 1.3 fl), with 24% of values above 10 fl. Only one had a platelet transfusion. Polycythemia was the next most common hematological abnormality detected, with 33% of hematocrit values above 65% or hemoglobin concentrations above 22 g/dl. Six had a reduction transfusion. One patient had significant anemia (hematocrit <15%) and received an erythrocyte transfusion. One had neutropenia associated with an infection after bowel surgery. Neutrophilia, thrombocytopenia, and polycythemia were the most common hematological abnormalities observed among neonates with Down syndrome. Anemia, thrombocytosis, and neutropenia were not more common than among neonates who do not have Down syndrome. Hematological abnormalities were so common in this group that it seems reasonable to recommend that one or more CBCs be obtained on all neonates with Down syndrome.

Blood Cell Count↗
PubMed2007

Treating feeding intolerance with an enteral solution patterned after human amniotic fluid: a randomized, controlled, masked trial.

OBJECTIVE: Feeding intolerance is a common problem in the neonatal intensive care unit (NICU) and some cases might be causally related to atrophic changes in the small bowel mucosa. We speculated that for such patients, feeding tolerance might improve after oral administration of enterocyte growth factors in a sterile, isotonic solution patterned after amniotic fluid. STUDY DESIGN: Twenty neonates meeting criteria for feeding intolerance were eligible for this trial. They were randomized to either Group 1 (test solution) or Group 2 (control). Group 1 received 2.5 ml of test solution/kg every 3 h by oral-gastric or nasal-gastric (OG/NG) tube. This was begun when the patient was NPO because of feeding intolerance and continued until 80 ml/k/day of milk feedings were tolerated, or for a maximum of 7 days. Group 2 received a sham OG/NG administration every 3 h, until 80 ml/k/day of milk feedings were tolerated, or for a maximum of 7 days. Only the bedside nurse and the NICU pharmacist were aware which patients received the test solution and which received the sham administrations. The volumes of milk feedings were increased by order of the attending neonatologist and nurse practitioner. The study outcome was enteral calories/kg/day during and for 7 days after the cessation of the treatments. RESULTS: Eleven patients were randomized to receive the test solution and nine to receive sham administrations. At study entry, the two groups were not different in gestational age, postnatal age, signs of feeding intolerance or cal/k/day taken enterally during the previous 3 days. The study doses were given for an average of just under 6 days (range, 2 to 7 days). During the week following the administrations, the test solution recipients trended toward more enteral calories. Specifically, they had an increase averaging 78+/-20.8 cal/k/day more than before the study, whereas the sham recipients had an increase averaging 55.9+/-33 cal/k/day more than before the study (P=0.05 for a one-sided test and P=0.10 for a two-sided test). The test solution recipients also had a trend toward fewer formula changes than did the sham recipients (P=0.10). In this small, randomized, controlled, masked trial, the administration of a sterile, non-caloric, growth factor containing solution patterned after human amniotic fluid was associated with trends that we interpret as reflecting better tolerance of milk feedings. On this basis, we suggest that a phase III efficacy trial should be accomplished, using the present data for sample size calculations.

Amniotic Fluid↗
PubMed2006

Low blood neutrophil concentrations among extremely low birth weight neonates: data from a multihospital health-care system.

OBJECTIVE: A blood neutrophil concentration < 1000/microl has been reported to occur in about 8% of neonatal intensive care unit (NICU) patients, at some time during their hospital stay. However, the incidence of this finding among extremely low birth weight (ELBW) neonates (< 1000 g birth weight) is not known. Using data from four NICU's in one health-care system, we sought to estimate the incidence, timing, causes, severity and duration of neutrophil counts < 1000/microl among ELBW neonates. We also tabulated the treatments used for this condition and associations with mortality. METHODS: We performed an historic cohort analysis of all ELBW neonates born during the 36-month period, 1 July 2002 to 30 June 2005, cared for in the four Intermountain Healthcare level III NICU's. RESULTS: Three hundred and thirty-eight ELBW neonates were the subjects of the analysis. Complete blood cell counts (CBCs) were obtained in all (range, 1 to 123 CBCs/patient). Thirty-eight percent (128/338) had one or more neutrophil counts < 1000/microl. In 57% the low neutrophil count persisted for < 24 h; in 43% it persisted for 1 to 7.5 days. Most of the cases (74%) were detected during the first 3 days of life. Twenty-two percent of cases were not detected until after the first week. Low neutrophil counts were more common among the smallest patients, with a 63% incidence in those < or = 500 g, 44% in those 501 to 600 g and 34% in those 801 to 999 g. When low neutrophil counts were recognized during the first 3 days of life, the patients were typically either small for gestational age (SGA; weight < 10th percentile for gestational age) or born after pregnancy-induced hypertension (PIH) (68%), or had early-onset bacterial infection (6%). When recognized after the first 3 days, the patients typically had necrotizing enterocolitis (31%) or a nosocomial bacterial infection (19%). Alloimmune mechanisms were not tested for in any of the cases. No cause for the low counts was identified among 35% of the neutropenic patients. Intravenous immunoglobulins was administered to 28% of cases, and 100% of these were given according to our written guidelines. Recombinant granulocyte-colony stimulating factor was administered to 13% of cases, and 69% of these were given according to guidelines. Neither the presence of low neutrophil counts nor the severity (lowest recorded count) correlated with mortality rate, except in proven early-onset sepsis. CONCLUSIONS: We observed low neutrophil counts among ELBW neonates at a rate five times that reported in the general NICU population. Most cases were present in the first days of life and occurred in SGA neonates or those with PIH. In over 1/3, no cause was discovered. We maintain that more consistency is needed in evaluating and treating neutropenia among ELBW neonates.

Cohort Studies↗
PubMed2006

Urinary excretion of darbepoetin after intravenous vs subcutaneous administration to preterm neonates.

OBJECTIVE: Previous studies suggest that darbepoetin might stimulate erythropoiesis in preterm neonates more effectively if injected subcutaneously (s.c.) than if infused intravenously (i.v.). It has been postulated that this is because very high plasma concentrations after i.v. dosing result in urinary loss of the drug. However, this theory has not been tested systematically, and no direct comparisons have been made between s.c. and i.v. dosing of darbepoetin in preterm neonates. STUDY DESIGN: Preterm neonates were eligible for this pilot study if they were born at < or =32 weeks gestation with a weight of < or =1500 g, and had a hemoglobin < or =10.5 g/dl. The darbepoetin was given (4 microg/kg) i.v., over 4 h, if an i.v. was already in place and s.c. if no i.v. was in place. Urine was collected for drug quantification before dosing and for 48 h after. Blood was obtained for immature reticulocyte fraction (IRF), absolute reticulocyte count (ARC) and reticulocyte % before and 96 h after dosing. RESULTS: Ten preterm neonates were studied: five received i.v. and five received s.c. darbepoetin. No adverse effects of the administrations were detected. IRF, ARC and reticulocyte % increased in the i.v. and s.c. recipients, and no difference in magnitude of increase was apparent between the groups. Before the darbepoetin was administered, none of the patients had any erythropoietin (Epo) detected in their urine. After i.v. dosing, no darbepoetin was detected in any of the samples, on any of the subjects, over the subsequent 48 h. After s.c. dosing, three of the patients had minimal urinary Epo detected. The patient with the largest urinary loss of drug had only 0.13% of the administered dose detected in the urine. Thus, essentially no urinary loss of drug was observed following either i.v. or s.c. darbepoetin dosing. CONCLUSION: Darbepoetin loss into the urine was below detectable limits among seven patients, while three had minimally detectable urinary losses. i.v. and s.c. dosing resulted in approximately equivalent increases in reticulocyte response when measured 96 h after dosing. On this basis, we speculate that if a patient who is to receive darbepoetin has an i.v. in place, the drug can be given i.v., thus avoiding any discomfort associated with an s.c. injection.

Darbepoetin alfa↗
PubMed2006

Comparing two methods of delivering high-flow gas therapy by nasal cannula following endotracheal extubation: a prospective, randomized, masked, crossover trial.

OBJECTIVE: We compared two methods of delivering high-flow gas therapy by nasal cannula, applied immediately after planned endotracheal extubations of NICU patients. STUDY DESIGN AND METHODS: Thirty NICU patients who were about to be extubated from mechanical ventilation were randomized into two groups; Group 1 received Vapotherm for the first 24 h after extubation, then standard high-flow nasal cannula for the next 24 h, and Group 2 received standard high-flow therapy for the first 24 h, then Vapotherm for the next 24 h. At 24 h after extubation and again 48 h after extubation, a neonatologist who was not aware which modality the patient had been receiving examined the nasal mucosa and applied a scoring system. A research nurse who was unaware of the modality abstracted respiratory rates and respiratory effort scores from a specific study-bedside record. The experimental design was such that a patient could 'fail' extubation either by reintubation for mechanical ventilation, or by rescue to the opposite modality before completing the 24-h test period. RESULTS: Fifteen patients were randomized to Group 1 and 15 to Group 2. No differences were apparent between the groups in birth weight, gestational age, age at study entry, gender or underlying pulmonary disorder. Respiratory rates were similar while on Vapotherm (52+/-13 breaths/min, mean+/-s.d.) and high-flow (54+/-14/min). At 24 h after starting the modality, those on Vapotherm had more normal examinations of the nasal mucosa (2.7+/-1.2 vs 7.8+/-1.7, P < 0.0005) and lower respiratory effort scores (1.2+/-0.6 vs 2.0+/-0.9, P < 0.05) than did those on high-flow. No patients failed while on Vapotherm, but seven failed while on high-flow (two reintubations and five rescue switches to Vapotherm, P < 0.005). CONCLUSIONS: Among NICU patients immediately following extubation, Vapotherm performed better than a standard high-flow nasal cannula in maintaining a normal appearing nasal mucosa, a lower respiratory effort score, and averting reintubation.

Birth Weight↗
PubMed2006

Testing for fetal exposure to illicit drugs using umbilical cord tissue vs meconium.

OBJECTIVE: We assessed the agreement of testing for fetal exposure to illicit drugs contrasting paired specimens of meconium vs umbilical cord tissue. METHODS: We obtained paired samples of meconium and umbilical cord tissue from 118 pregnancies with high suspicion of illicit drug use by the mothers. Each specimen was tested for amphetamines, opiates, cocaine, cannabinoids, and phencyclidine using drug class-specific immunoassays. RESULTS: The agreement of drug screening results between cord and meconium was above 90% for all drugs tested. Meconium identified 21 cases as positive for amphetamines. The paired cord identified 20 of these, and in addition identified three other positives that the meconium labeled as negative. Gas chromatography-mass spectrometry confirmed these three cord samples as methamphetamine positive. Meconium identified 97 samples that were negative for amphetamines, while the cord identified 94 of these as negative but three as positive. Agreement of cord with meconium for amphetamines was 96.6%. The concordance for opiates was 94.9%, for cocaine was 99.2%, and for cannabinoids was 90.7%. CONCLUSIONS: Umbilical cord tissue performs as well as meconium in assessing fetal drug exposure to amphetamines, opiates, cocaine, and cannabinoids. Results of studies using the cord may have a more rapid return to the clinician, because waiting for meconium to be passed sometimes requires several days. Moreover, in some cases the meconium is passed in utero making collection impossible, whereas cord should always be available for drug testing.

Amphetamines↗
PubMed2006

Pattern of daily weights among low birth weight neonates in the neonatal intensive care unit: data from a multihospital health-care system.

OBJECTIVES: We sought to generate a contemporary postnatal weight grid for low birth weight (LBW, <2500 g) neonates using actual data, not mathematically derived idealized weight curves. To do this, we collected electronic data from all neonatal intensive care units (NICU) patients weighing 400-2600 g at birth, during 30 consecutive months (January 2003-June 2005) in all four NICU's within a single health system, Intermountain Health Care (IHC). METHODS: A deidentified limited data set was collected from electronic IHC records. Data were limited to the birth weights and all subsequent daily weights, until discharge, death, or transfer to a non-IHC facility. Lines were drawn connecting the exact daily means of body weight for patients in 200 g birth weight groupings, ranging from 400 to 2600 g. We assessed differences in growth patterns predicted by this grid vs three previously published NICU longitudinal weight grids. RESULTS: All recorded weights were electronically extracted for 1813 consecutive patients with dates of birth from January 1, 2003 through June 30, 2005. The daily weights of each patient totaled over 48,000 individual data points. The new grid differed from previously published grids, in that the new grid showed; (1) no predicted postnatal weight loss among neonates in categories<900 g birth weight, (2) less initial weight loss among neonates 900-2500 g, (3) fewer days to regain birth weight among neonates<or=2000 g, and (4) fewer days to gain 100 and 300 g above birth weight in neonates<or=1500 g. SPECULATION: For charting serial weights of LBW neonates in the NICU the new grid may be a useful standard.

Body Weight↗
PubMed2006

A pilot trial testing the feasibility of administering D-penicillamine to extremely low birth weight neonates.

OBJECTIVE: We enterally administered a 14-day course of 3-mercapto-D-valine (D-penicillamine) to five extremely low birth weight (ELBW) neonates, as a step toward assessing this therapy as a means of reducing the incidence or severity of retinopathy of prematurity (ROP). METHODS: The study drug (100 mg/ml) was given by nasogastric tube at a dose of 100 mg/k every 8 h for three days, and then 50 mg/k once per day for 11 additional days. Logbooks were maintained by the bedside nurses to record signs of possible immediate intolerance. Laboratory tests assessed hepatic, renal, and hematologic toxicity. ROP was scored according to the ICROP guidelines. Comparisons were with a cohort of 139 consecutive recent neonates of the same birth weight and gestational age range. RESULTS: Five neonates were enrolled in the study, and all received the full course of study drug as planned. Signs of immediate intolerance of the study drug were not observed in any. The study patients did not have a higher incidence, than that of the cohort group, in creatinine elevation, thrombocytopenia, neutropenia, hyperbilirubinemia, or abnormal liver function test. Four of the five had no ROP and one developed transient stage 1, compared with a 54% occurrence of ROP in the cohort. CONCLUSIONS: It is feasible to enterally administer a 14-day course of 3-mercapto-D-valine to ELBW neonates and the suspension appears to be well tolerated. These results suggest that phase II safety and preliminary efficacy trials can be undertaken.

Birth Weight↗
PubMed2006

Intravenous administration of darbepoetin to NICU patients.

OBJECTIVE: Darbepoetin can be administered either intravenously (i.v.) or subcutaneously (s.c.). However, no information is available regarding pharmacokinetics and pharmacodynamics following its i.v. administration to neonates. STUDY DESIGN: We administered a single i.v. dose (4 microg/kg) of darbepoetin to 10 neonates who had a hemoglobin < or =10.5 g/dl. Blood was obtained for immature reticulocyte fraction (IRF) and absolute reticulocyte count (ARC), before and 48 h following the dose. Blood was also drawn for pharmacokinetic analysis once before and at four pre-set intervals after dosing. RESULTS: The study subjects ranged from 704 to 3025 g (median, 1128 g) birth weight, and were 26.0-40.0 weeks (median, 29.2 weeks) gestation at delivery. When the darbepoetin dose was given, ages ranged from 3 to 28 days (median, 8.5 days) with a hemoglobin of 9.8 +/- 0.7 g/dl (mean +/- s.d.). Doses were administered by i.v. infusion over 4 h. No adverse effects of the infusions were detected. The half-life of darbepoetin (t (1/2)) was 10.1 h (range 9.0-22.7 h), the volume of distribution was 0.77 l/kg (range 0.18-3.05 l/kg) and the clearance was 52.8 ml/h/kg (range 22.4-158.0 ml/h/kg). In the preterm neonates, there was no significant correlation between gestational age, or age at darbepoetin administration, and pharmacokinetic parameters. However, in the term and near-term neonates, volume of distribution correlated significantly with both gestational and age at darbepoetin administration (P < 0.05). Forty-eight hours after dosing, the IRFs and ARCs were elevated in six subjects and not in four. Those with predosing reticulocyte counts >200,000/microl did not have an increase in reticulocytes by 48 h (P < 0.05). CONCLUSIONS: Darbepoetin administered i.v. to neonates had a shorter t (1/2), a larger volume of distribution and more rapid clearance than reported in children. We observed a significantly shorter t (1/2) and a less consistent rise in IRF and ARC after i.v. dosing than we previously reported following 4 microg/kg administered SC.

Birth Weight↗
PubMed2006

Thrombocytopenia among extremely low birth weight neonates: data from a multihospital healthcare system.

OBJECTIVES: Thrombocytopenia is common in neonatal intensive care units (NICU), with 18 to 35% of patients developing this problem before hospital discharge. It might be even more common among extremely low birth weight neonates (ELBW, < or = 1000 g birth weight). However, little is known about thrombocytopenia in the ELBW population. We sought to determine the incidence, timing, causes, platelet transfusions given, and outcomes of thrombocytopenia among ELBW neonates. STUDY DESIGN: We performed a cohort analysis of all 284 ELBW neonates born during 2003 and 2004 cared for in any of the Intermountain Healthcare level III NICUs. RESULTS: Multiple platelet counts were obtained in all 284 (range, 4 to 441 platelet counts/patient). Of the 284, 208 (73%) had one or more platelet counts < or =150 000/microl. Most were detected during the first days of life; 80% were detected during the first week and only 20% were detected thereafter. Thrombcytopenia was more common among the smallest patients; 85% incidence among those < or =800 g, 60% among those 801 to 900 g, and 53% among those 901 to 1000 g. Platelet transfusions were given to 129 of the 208 thrombocytopenic neonates. More than 90% were given prophylactically (the patient was not bleeding). The mortality rate among those that received platelet transfusions was twice that of those that received no platelet transfusions (P < 0.01). In 48% of cases, the cause of the thrombocytopenia went undiagnosed. The most common explanations were being small for gestational age or delivered to a hypertensive mother, DIC, bacterial infection, fungal infection, and necrotizing enterocolitis, respectively. CONCLUSIONS: We observed thrombocytopenia among ELBW neonates at a rate more than twice that reported among the general NICU population. Much remains to be discovered about the etiology and best treatments of thrombocytopenia among ELBW neonates.

Cohort Studies↗
PubMed2002

Immune-mediated neutropenia in the neonate.

Alloimmune neonatal neutropenia, neonatal autoimmune neutropenia and autoimmune neutropenia of infancy have remained nebulous entities with difficulties in both clinical and laboratory identification. These disorders are reviewed in this article.

Adrenal Cortex Hormones↗
PubMed2001

Granulocyte colony-stimulating factor in preterm and term pregnancy, parturition, and intra-amniotic infection.

OBJECTIVE: [corrected] To determine the sources of granulocyte colony-stimulating factor (G-CSF) in amniotic fluid and to examine its relation to labor and clinically diagnosed intra-amniotic infection. METHODS: We assessed G-CSF and G-CSF receptor expression in placentas (n = 50) from 5-40 weeks' gestation, and G-CSF concentrations were measured in amniotic fluid (n = 146), bronchoalveolar lavage fluid (n = 8), and paired maternal serum, cord blood, neonatal serum, and neonatal urine samples (n = 16). RESULTS: Immunohistochemical staining and messenger RNA analysis showed placental expression of G-CSF and G-CSF receptor throughout gestation. The number of decidual stromal cells expressing G-CSF receptor was significantly higher in women with intra-amniotic infection compared with women without infection (27 +/- 2 versus 18 +/- 3 cells per high power field, P =.02). Amniotic fluid concentrations of G-CSF were not significantly different in noninfected preterm compared with term samples (1708 +/- 1673 versus 1612 +/- 2100 pg/mL, P =.9). Labor was not associated with a significant increase in amniotic fluid G-CSF concentrations (1864 +/- 3151 versus 1612 +/- 2100 pg/mL, P =.77, term labor versus no labor; 3335 +/- 5364 versus 1708 +/- 1673 pg/mL, P =.09, preterm). Concentrations of G-CSF in maternal serum, amniotic fluid, bronchoalveolar lavage fluid, and neonatal urine were increased during intra-amniotic infection (all P <.05). CONCLUSION: Amniotic fluid G-CSF concentrations were similar in preterm and term pregnancies and were not significantly influenced by labor. Intra-amniotic infection was associated with an increased number of placental cells expressing the G-CSF receptor and higher concentrations of G-CSF in amniotic fluid, maternal serum, neonatal urine, and neonatal bronchoalveolar lavage samples.

Adult↗
PubMed2001

Cell cycle status of CD34+ cells in human fetal bone marrow.

We used flow cytometric analysis to determine the cell cycle characteristics of human CD34+ cells from fetal bone marrow (BM), adult BM, and umbilical cord blood (UCB) samples. Fetal BM had three-fold more cells in the S-phase than did adult BM or UCB.

Adult↗
PubMed2001

The relationship between hematocrit and bleeding time in very low birth weight infants during the first week of life.

OBJECTIVES: The bleeding time is a measurement of platelet and capillary interaction following a small standardized cutaneous incision. In adults, anemia causes a prolongation of the bleeding time, and we hypothesized that the same would be true in very low birth weight (VLBW) infants during their first week of life. STUDY DESIGN: Template bleeding times, using the Surgicutt Newborn device, were performed on 20 VLBW weight infants 0.28 l/l had no significant reduction in bleeding time following transfusion. CONCLUSIONS: In VLBW infants, during their first week of life (the time when their risk of intraventricular hemorrhage is greatest), a low hematocrit is associated with a significant prolongation in the bleeding time.

Bleeding Time↗
PubMed2001

Platelet transfusions in the neonatal intensive care unit:factors predicting which patients will require multiple transfusions.

BACKGROUND: Previous studies suggest that recombinant thrombopoietin (rTPO) will increase platelet production in thrombocytopenic neonates. However, the target populations of neonates most likely to benefit should be defined. Studies suggest that rTPO will not elevate the platelet count until 5 days after the start of treatment. Therefore, the neonates who might benefit from rTPO are those who will require multiple platelet transfusions for more than 5 days. This study was designed to find means of prospectively identifying these patients. STUDY DESIGN AND METHODS: A historic cohort study of all patients in the neonatal intensive care unit (NICU) at the University of Florida who received platelet transfusions from January 1, 1997, through December 31, 1998, was conducted. RESULTS: Of the 1389 patients admitted to the NICU during the study period, 131 (9.4%) received platelet transfusions. Seventeen were treated with extracorporeal membrane oxygenation and were excluded from further analysis. Of the remaining 114 patients, 55 (48%) received one transfusion and 59 (52%) received more than one transfusion (21 had >4). None of the demographic factors examined predicted multiple platelet transfusions. However, two clinical conditions did; liver disease and renal insufficiency. Neonates who received one platelet transfusion had a relative risk of death 10.4 times that in neonates who received none (p = 0.0001). Neonates who received >4 platelet transfusions had a risk of death 29.9 times that in those who received no transfusions (p = 0.0001). CONCLUSION: NICU patients with liver disease or renal insufficiency who receive one platelet transfusion are likely to receive additional transfusions. Therefore, these patients constitute a possible study population for a Phase I/II rTPO trial.

Cohort Studies↗
PubMed2001

Transfer of recombinant human granulocyte colony stimulating factor (rhG-CSF) from the maternal to the fetal circulation is not dependent upon a functional G-CSF-receptor.

Administration of granulocyte colony stimulating factor (G-CSF), a haematopoietic growth factor, to pregnant rats increases neutrophil production in the pups. The mechanism for the placental transfer is unknown, but it has been speculated to involve the placental G-CSF receptor (G-CSFR). The purpose of this study was to test that hypothesis. Pregnant mice were treated with a single subcutaneous dose of 50 microg/kg recombinant human G-CSF (rhG-CSF). Mice with an intact G-CSFR ("wild type", WT) and those with a homozygous deletion in the G-CSFR gene (G-CSFR deficient, "knock-out", KO) were studied. At intervals after injection, fetuses were delivered and maternal blood, amniotic fluid (AF) and fetal blood collected. G-CSF concentrations were measured using an enzyme linked immunosorbent assay specific for human G-CSF. Thirty minutes after injection, G-CSF was measurable in the AF (167+/-50 versus 445+/-217 pg/ml, mean+/-sem, WT versus KO) and fetal plasma (774+/-673 versus 427+/-121 pg/ml, WT versus KO). Peak concentrations occurred 2 h after injection in WT dams (572 542+/-41 262 pg/ml) and 4 h in KO dams (616 100+/-96 300 pg/ml). Therefore, in mice, a functional G-CSFR is not essential for the transfer of rhG-CSF from pregnant dams to their fetuses.

Amniotic Fluid↗
PubMed2001

Administration of recombinant granulocyte colony-stimulating factor to neonates with septicemia: A meta-analysis.

A meta-analysis was used to determine whether administering recombinant granulocyte colony-stimulating factor (rG-CSF) to neonates with bacterial septicemia reduces mortality. Five studies were identified, involving 73 rG-CSF recipients and 82 control subjects. Mortality was lower among the rG-CSF recipients (odds ratio, 0.17; CI, 0.03-0.70; P <.05). However, when the non-randomized studies were excluded, the P value was.13. For the subgroups "<2000 g" or "neutropenia," the P value was <.02. Thus the routine use of rG-CSF cannot be recommended for all neonates with sepsis.

Granulocyte Colony-Stimulating Factor↗