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Biomedical subjects

P Crowley

Publications and source records attributed to P Crowley.

At least 19 recordsLinked to original sources
PubMed2002

Effects of human placental lactogen on the expression of CD163 and CD14 on human monocytes in culture.

The effect of human placental lactogen (hPL), a member of the somatomammotrophin family, on the regulation of the scavenger receptor molecules CD14 and CD163 on human monocytes cultured for 48h was investigated. Cells were cultured in the presence or absence of the hormone and also in the presence or absence of IFN-gamma and dexamethasone. Monocytes cultured in the presence of hPL showed a significant increase in the expression of CD14 in both males and females compared to background. When IFN-gamma and dexamethasone were added to the cultures, CD14 expression was decreased and was not rescued by the presence of hPL. hPL alone had no effect on the expression of CD163 on cultured monocytes from either gender, although cells cultured in the presence of IFN-gamma and dexamethasone showed a profound increase in their expression of CD163. This expression was augmented further by the presence of hPL in the cultures over a 48-h period. These results support the hypothesis of a potential role of this hormone in the regulation of the innate immune response.

Anti-Inflammatory Agents↗
PubMed2000

Prophylactic corticosteroids for preterm birth.

BACKGROUND: Respiratory distress syndrome is a serious complication of prematurity causing significant immediate and long-term mortality and morbidity. OBJECTIVES: The objective of this review was to assess the effects of corticosteroids administered to pregnant women to accelerate fetal lung maturity prior to preterm delivery. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched. SELECTION CRITERIA: Randomised and quasi-randomised trials of corticosteroid drugs capable of crossing the placenta compared with placebo or no treatment in women expected to deliver preterm as a result of either spontaneous preterm labour, prelabour rupture of the membranes preterm, or elective preterm delivery. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed by one reviewer. MAIN RESULTS: Eighteen trials including data on over 3700 babies were included. Antenatal administration of 24 milligrams of betamethasone, of 24 milligrams of dexamethasone, or two grams of hydrocortisone to women expected to give birth preterm was associated with a significant reduction in mortality (odds ratio 0.60, 95% confidence interval 0.48 to 0.75), respiratory distress syndrome (odds ratio 0.53, 95% confidence interval 0.44 to 0.63) and intraventricular haemorrhage in preterm infants. These benefits extended to a broad range of gestational ages and were not limited by gender or race. No adverse consequences of prophylactic corticosteroids for preterm birth have been identified. REVIEWER'S CONCLUSIONS: Corticosteroids given prior to preterm birth (as a result of either preterm labour or elective preterm delivery) are effective in preventing respiratory distress syndrome and neonatal mortality. However there is not enough evidence to evaluate the use of repeated doses of corticosteroids in women who remain undelivered, but who are at continued risk of preterm birth. (This abstract has been prepared centrally.)

Female↗
PubMed2000

Interventions for preventing or improving the outcome of delivery at or beyond term.

BACKGROUND: Perinatal mortality and morbidity is increased in pregnancies of more than 42 weeks that are otherwise low risk. OBJECTIVES: The objective of this review was to assess the effects of interventions aimed at either reducing the incidence or improving the outcome of post-term pregnancy. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched. SELECTION CRITERIA: Randomised and quasi-randomised trials of interventions involving the intention to induce labour at a specified gestational age. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed by one reviewer. Study authors were contacted for additional information. MAIN RESULTS: Twenty-six trials of variable quality were included. There were four trials of routine early pregnancy ultrasound, two of nipple stimulation, nineteen of routine versus selective induction of labour and one of antenatal fetal monitoring. Routine early pregnancy ultrasound reduced the incidence of post-term pregnancy (odds ratio 0.68, 95% confidence interval 0.57 to 0.82). Breast and nipple stimulation at term did not affect the incidence of post-term pregnancy (odds ratio 0.52, 95% confidence interval 0.28 to 0.96). Routine induction of labour reduced perinatal mortality (odds ratio 0.20, 95% confidence interval 0.06 to 0.70). This benefit is due to the effect of induction of labour after 41 weeks. Routine induction of labour had no effect on caesarean section. REVIEWER'S CONCLUSIONS: Routine early pregnancy ultrasound examination and subsequent adjustment of delivery date appear to reduce the incidence of post-term pregnancy. Routine induction of labour after 41 weeks gestation appears to reduce perinatal mortality. There is not enough evidence to evaluate the effects of breast and nipple stimulation, or tests of fetal wellbeing.

Delivery, Obstetric↗
PubMed2000

The assessment of the effect of thyroid size and shape on the activity estimate using Monte Carlo simulation.

Monte Carlo simulations have been used to assess the uncertainty introduced into an activity estimate of radioiodine (125I and 131I) in the thyroid when the size and shape of the gland differs from that of the calibration phantom. The detector dimensions for the 125I simulations were small (diameter 2.54 cm, thickness 0.2 cm); medium (diameter 7.62 cm, thickness 0.2 cm); large (diameter 30.48 cm, thickness 0.2 cm). The detector dimensions for the 131I simulations were small (diameter 2.54 cm, thickness 3.2 cm); medium (diameter 7.62 cm, thickness 6.4 cm); large (diameter 30.48 cm, thickness 11.0 cm). Shapes simulated have included thyroid glands with a third (pyramidal) lobe, no isthmus, and rotated lobes. Sizes simulated have been 10 g, 20 g, and 40 g. The results show that the size of the uncertainty is dependent on the detector size, the neck-to-detector distance, and the type of radioiodine being measured (i.e., 131I or 125I). The worst case bias (on contact counting) for either 125I or 131I using the different sized detectors is as follows: small is between -40% and 40%; medium is between -33% and 17%; large is between -20% and 5%. If the detectors are placed at about 15 cm from the neck the bias values drop so that the uncertainty introduced if the subject has a smaller than standard thyroid becomes insignificant and becomes much improved if the thyroid is larger than the standard. The bias values for the detectors are as follows: small is between -20% and 5%; medium is between -23% and 2%; large is between -21% and 2%.

Calibration↗
PubMed2000

The uncertainty in the activity estimate from a lung count due to the variability in chest wall thickness profile.

Calibration of a lung counter requires the use of a realistic torso phantom. The depth profile of both torso phantoms' (LLNL and JAERI) chest plate covers is fixed and assumed to be equivalent to a person's chest wall; however, ultrasound measurements of humans have shown this to be an approximation. When the depth profile of a calibration phantom is different from that of a subject, then a systematic uncertainty will be introduced into the activity estimate. Monte Carlo simulation has shown that changes in the depth profile of the chest wall thickness affect the counting efficiency. Ultrasound measurements have suggested that the coefficient of variation in the depth profile of the chest wall thickness lies between 13% and 26% for male workers; therefore, the added uncertainty to an activity estimate will be an over or underestimate of about a factor of 1.07 resulting from the different depth profile. The factor will be somewhat higher for females, probably about 1.2 at the extreme. These additional uncertainties resulting from depth profile differences are small compared with other uncertainties commonly encountered in lung counting: detector positioning, deposition patterns of the activity, measurement of the chest wall thickness, etc.

Computer Simulation↗
PubMed1999

Abnormal prenatal sonographic findings in the posterior cranial fossa: a case of Joubert's syndrome.

Joubert's syndrome is a well-documented but rare disorder characterized by a variable combination of central nervous system, respiratory, renal and eye anomalies. The most significant and constant neuropathological finding is partial or complete agenesis of the cerebellar vermis. The syndrome was first described by Joubert and colleagues as a familial agenesis of the cerebellar vermis and appears to be inherited as an autosomal recessive trait. A case of Joubert's syndrome is described in which second-trimester ultrasonography demonstrated abnormal findings in the fetal posterior fossa with associated renal abnormalities. However, postnatal sonography of the posterior fossa could not confirm the prenatal findings, and the diagnosis of Joubert's syndrome was only later established by computed tomography of the neonatal brain in the knowledge of the characteristic clinical picture.

Abnormalities, Multiple↗
PubMed1995

Chemical modification of a cloned glutathione S-transferase from Schistosoma japonicum: evidence for an essential histidine residue.

Diethylpyrocarbonate (DEP) inhibits the catalytic activity of a cloned glutathione S-transferase from Schistosoma japonicum (Sj26GST) with a second-order rate constant of 474 M-1 min-1 at pH 7.0 and 25 degrees C. There is an accompanying increase in absorbance at 242 nm due to the formation of N-carbethoxyhistidyl derivatives. There was no evidence that tyrosine or cysteine residues were modified by DEP treatment nor did the enzyme undergo any major conformational change. Activity can be restored by treating the DEP-modified enzyme with hydroxylamine and the pH curve for inactivation indicates involvement of a residue with a pKa of 7.3. Complete inactivation of Sj26GST requires the modification of six histidine residues per subunit. Statistical analysis of residual enzyme activity versus number of groups modified showed that of the six modifiable groups, only one is critical for activity. Substrate protection suggests that this essential histidine residue is at or near the active site.

Animals↗
PubMed1993

Biochemical properties of cloned glutathione S-transferases from Schistosoma mansoni and Schistosoma japonicum.

cDNA clones encoding a 28-kDa subunit glutathione S-transferase (GST) from Schistosoma mansoni (Sm28GST) and a 26-kDa subunit GST from Schistosoma japonicum (Sj26GST) have been expressed in bacterial systems. The recombinant proteins were purified to homogeneity by batch-wash glutathione-agarose affinity chromatography and their biochemical properties investigated. Gel filtration chromatography indicated that both recombinant GSTs are homodimeric proteins. Resolution of Sm28GST and Sj26GST by chromatofocusing in the ranges pH 9-6 and pH 7-4 gave pI estimates of 7.4 and 5.0, respectively. Kinetic analyses suggested that both Sm28GST and Sj26GST operate via a sequential bisubstrate catalytic mechanism. Sm28GST and Sj26GST displayed a mosaic of mammalian Alpha-, Mu- and Pi-type substrate specificities and inhibitor sensitivities. However, multivariate analysis suggests that Sm28GST has an overall catalytic homology with mammalian Mu class GSTs, whilst the enzymatic properties of Sj26GST appear to constitute a hybridisation of Mu and Alpha class features. Both recombinant GSTs interact with a range of hydrophobic ligands including haematin and related compounds, bile acids and several anthelmintics. Sm28GST and Sj26GST possess relatively limited selenium-independent glutathione peroxidase activities, but are able to catalyse the glutathione conjugation of members of the trans,trans-alka-2,4-dienal, trans-alk-2-enal and 4-hydroxyalk-2-enal series of reactive carbonyls (known secondary products of lipid peroxidation).

Animals↗
PubMed1992

Corticosteroids after preterm premature rupture of membranes.

A review of all relevant randomized controlled trials provides strong evidence that corticosteroid therapy causes a significant reduction in respiratory distress syndrome (RDS) in preterm babies overall. This reduction in RDS is accompanied by a reduced incidence of neonatal death, intraventricular hemorrhages, and necrotizing enterocolitis. These benefits are also seen in cases of PROM. Corticosteroid therapy in PROM is associated with a trend toward an increase in neonatal infection.

Adrenal Cortex Hormones↗
PubMed1991

Delivery in an obstetric birth chair: a randomized controlled trial.

OBJECTIVE: To determine whether nulliparae whose second stage of labour is conducted in an obstetric birth chair have a lower incidence of instrumental delivery than those using a conventional delivery bed. DESIGN: Randomized controlled trial using sealed, opaque envelopes for allocation. SETTING: Delivery ward in a busy teaching hospital. PATIENTS: 1250 nulliparae with a singleton live fetus with cephalic presentation, without epidural anaesthesia, who had achieved full dilatation. INTERVENTION: Intention to conduct second and third stages of labour in either the Birth-EZ chair or the conventional delivery bed, as randomly allocated. MAIN OUTCOME MEASURES: Primary measure: vaginal operative delivery; principal secondary measures: duration of second stage, perineal trauma, blood loss, women's views, and neonatal status. RESULTS: Delivery in the birth chair did not result in a reduction in operative delivery, overall. However, there was a reduction in vaginal operative delivery for fetal heart rate abnormality. There was no beneficial effect on perineal trauma or puerperal perineal pain. Post-partum haemorrhage was more frequent in the birth chair group. CONCLUSIONS: Delivery in the birth chair does not offer any obvious advantage to women over delivery on a bed.

Consumer Behavior↗