Microdetermination of nitrates and nitramines-I Titrimetric methods based on the reduction with iron(II), titanium(III), and a mixture of both

Organic and inorganic nitrates are satisfactorily determined on the microscale by reduction with Fe(II). Titanium(III) reduces the nitrates in strongly acidic, citrate-buffered, and acetate-buffered media with the comsumption of 3, 6 and 8 equivalents respectively of Ti(III) per nitrate group. Nitramines are determined by reduction with a mixture of Ti(III) and Fe(II). Determination of nitrates and nitramines by trans-nitration with salicylic acid is suitable on the microscale. A new electrolytic reduction automatic microburette was devised for the reduction, storage and use of the titanium(III) solution.

Flow injection analysis of sulfite ion with a potentiometric titanium phosphate-epoxy based membrane sensor

A potentiometric sensor based on the use of titanium phosphate (TP) in epoxy matrix membrane is prepared and characterized. The sensor exhibits near-Nernstian response for many anionic species over the concentration range 10(-1)-10(-5) mol l(-1). The origin of response is explained on the basis of the conversion of titanium phosphate cation exchanger into hydrated titanium oxide anion exchanger by the effect of the high pH of the epoxy matrix. The sensitivity and selectivity of the sensor for sulfite ions are optimized by conversion of sulfite into gaseous SO(x) by acidification, and diffusion of the gas through a membrane-based gas dialyzer followed by potentiometric detection of sulfite ions formed within a flowing recipient stream. No interferences are caused by many common anions and acidic gas releasing species except sulfide and nitrite ions. Determination of sulfite ion at levels as low as 10(-4) mol l(-1) or less in the presence of nitrite and sulfide ions is performed by using a modified carrier buffer stream (10(-2) mol l(-1) MES, pH 5.0 containing sulfamic acid) and pretreatment with Pb(2+). Advantages offered by the proposed gas dialyzer/flow injection system with TP-epoxy membrane based sensor over traditional ion exchange based sensors includes long life time (>8 months), excellent stability and reproducibility ( approximately 1 mV), fast response time (<30 s), wide pH working range (pH 5-9), high sample throughput ( approximately 60 samples h(-1)), low detection limit (8x10(-6) mol l(-1)) and high thermal stability (up to 80 degrees C).

Vaginal progesterone reduces the rate of preterm birth in women with a sonographic short cervix: a multicenter, randomized, double-blind, placebo-controlled trial

OBJECTIVES

Women with a sonographic short cervix in the mid-trimester are at increased risk for preterm delivery. This study was undertaken to determine the efficacy and safety of using micronized vaginal progesterone gel to reduce the risk of preterm birth and associated neonatal complications in women with a sonographic short cervix.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled trial that enrolled asymptomatic women with a singleton pregnancy and a sonographic short cervix (10-20 mm) at 19 + 0 to 23 + 6 weeks of gestation. Women were allocated randomly to receive vaginal progesterone gel or placebo daily starting from 20 to 23 + 6 weeks until 36 + 6 weeks, rupture of membranes or delivery, whichever occurred first. Randomization sequence was stratified by center and history of a previous preterm birth. The primary endpoint was preterm birth before 33 weeks of gestation. Analysis was by intention to treat.

RESULTS

Of 465 women randomized, seven were lost to follow-up and 458 (vaginal progesterone gel, n=235; placebo, n=223) were included in the analysis. Women allocated to receive vaginal progesterone had a lower rate of preterm birth before 33 weeks than did those allocated to placebo (8.9% (n=21) vs 16.1% (n=36); relative risk (RR), 0.55; 95% CI, 0.33-0.92; P=0.02). The effect remained significant after adjustment for covariables (adjusted RR, 0.52; 95% CI, 0.31-0.91; P=0.02). Vaginal progesterone was also associated with a significant reduction in the rate of preterm birth before 28 weeks (5.1% vs 10.3%; RR, 0.50; 95% CI, 0.25-0.97; P=0.04) and 35 weeks (14.5% vs 23.3%; RR, 0.62; 95% CI, 0.42-0.92; P=0.02), respiratory distress syndrome (3.0% vs 7.6%; RR, 0.39; 95% CI, 0.17-0.92; P=0.03), any neonatal morbidity or mortality event (7.7% vs 13.5%; RR, 0.57; 95% CI, 0.33-0.99; P=0.04) and birth weight < 1500 g (6.4% (15/234) vs 13.6% (30/220); RR, 0.47; 95% CI, 0.26-0.85; P=0.01). There were no differences in the incidence of treatment-related adverse events between the groups.

CONCLUSIONS

The administration of vaginal progesterone gel to women with a sonographic short cervix in the mid-trimester is associated with a 45% reduction in the rate of preterm birth before 33 weeks of gestation and with improved neonatal outcome.

The vaginal microbiome: new information about genital tract flora using molecular based techniques

Vaginal microbiome studies provide information that may change the way we define vaginal flora. Normal flora appears dominated by one or two species of Lactobacillus. Significant numbers of healthy women lack appreciable numbers of vaginal lactobacilli. Bacterial vaginosis (BV) is not a single entity, but instead consists of different bacterial communities or profiles of greater microbial diversity than is evident from cultivation-dependent studies. BV should be considered a syndrome of variable composition that results in different symptoms, phenotypical outcomes, and responses to different antibiotic regimens. This information may help to elucidate the link between BV and infection-related adverse outcomes of pregnancy.

Selective reduction in complicated monochorionic pregnancies: radiofrequency ablation vs. bipolar cord coagulation

OBJECTIVE

To compare radiofrequency ablation (RFA) and bipolar cord coagulation (BPC) methods for selective fetal reduction in the treatment of complicated monochorionic (MC) multifetal gestations.

METHODS

This was a retrospective review of patients who underwent selective reduction by RFA and BPC. Computer-generated random sampling was performed to match patients who had undergone BPC with patients who had undergone RFA, in a 2 : 1 ratio, controlling for gestational age and indication. The primary outcome was fetal survival.

RESULTS

Twenty patients in the RFA group were matched with 40 patients in the BPC group. Fewer additional intra-operative procedures were performed in the RFA group compared with the BPC group: amnioinfusion, 10% vs. 75%, respectively (P < 0.01); and amnioreduction, 5% vs. 40%, respectively (P = 0.004). The overall survival rates were 87.5% in the RFA group and 88% in the BPC group (P = 0.94). Median gestational age at delivery was 36 (range, 26-41) weeks in the RFA group and 39 (range, 19-40) weeks in the BPC group (P = 0.59). Preterm delivery (at < 28, < 32 or < 37 weeks), weeks gained after the procedure and birth weight at delivery were also similar. Although the preterm premature rupture of membranes (PPROM) rate was higher in the BPC group (22.5%) compared with the RFA group (5%), the difference was not statistically significant (P = 0.09).

CONCLUSIONS

Overall fetal survival rate following selective reduction in complicated MC pregnancies is similar whether reduction is performed by RFA or BPC. Fewer additional intraoperative procedures are required for RFA than for BPC. The possibility that RFA is associated with a lower rate of postoperative PPROM than is BPC will have to be confirmed in larger series.

Standardization and application of indirect plate ELISA for immunodiagnosis of paramphistomosis in ruminants

Indirect plate enzyme-linked immunosorbent assay was standardized and evaluated for its effectiveness in immunodiagnosis of paramphistomosis in experimental and clinical cases in sheep, goat, cattle and buffaloes by using somatic whole adult antigen of Paramphistomum epiclitum and Gastrothylax crumenifer. Plate enzymelinked immunosorbent assay (ELISA) was standardized using 2 μg/ml of antigen concentration with 1:200 and 1:1,000 of sera and conjugate dilution. Indirect Plate ELISA was able to demonstrate the antibody titre at different weeks postinfection in experimental sheep. Immune response at weekly interval varied in all the four experimental sheep. A paired t-test between two types of somatic antigens (P. epiclitum and G. crumenifer) showed that experimental sheep sera showed more affinity for homologous antigen as compared to heterologous antigen. A comparison of plate ELISA on suspected field sera and fecal samples examination by sedimentation method revealed that 77 samples were found to be positive by ELISA but only seven by fecal examination. Sensitivity of plate ELISA was found to be 85.71%, whereas specificity was 23.65% indicating that this test is quite sensitive for clinical cases; an early diagnosis, however, lacks specificity. In comparison to ELISA test the sensitivity and specificity of fecal examination were 7.79 and 88%, respectively.

Iliac crest angle: a novel sonographic parameter for the prediction of Down syndrome risk during the second trimester of pregnancy

OBJECTIVES

To validate a new sonographic technique for the display and measurement of fetal iliac crest angle (ICA), and to determine the relative contribution of standardized fetal pelvic measurements for estimating risk of Down syndrome during the second trimester of pregnancy.

METHODS

Three-dimensional ultrasonography of the fetal pelvis was performed during a second-trimester scan for genetic amniocentesis. A coronal view of the 'virtual pelvis' was obtained by applying a maximum intensity projection algorithm to visualize both iliac wings. Two different ICAs were measured from a coronal projection of the fetal pelvis (ICA-coronal 1 and ICA-coronal 2); the latter approach relied on using ischial tuberosities as reference landmarks. Next, a coronal projection of the fetal pelvis was rotated to demonstrate a rendered view of the axial fetal pelvis. Axial inner (ICA-inner), middle (ICA-middle) and outer (ICA-outer) ICAs were measured. The maximum anterior iliac distance measurement was defined as the widest separation between the most anterior points of the rendered iliac crests. The reproducibility of each ICA method was analyzed using Bland-Altman statistics. Simple and multiple logistic regression analysis determined the relative contribution of each parameter as a prenatal predictor of Down syndrome.

RESULTS

Ninety-four normal fetuses and 19 fetuses with Down syndrome were examined. The ICA-middle and ICA-coronal 2 parameters were the most reproducible angle measurements. The mean +/- SD ICA-middle measurement for fetuses with Down syndrome was significantly greater than that for normal subjects (94.5 +/- 9.8 degrees vs. 83.1 +/- 6.5 degrees ; P < 0.001). The mean +/- SD ICA-coronal 2 angle measurement for fetuses with Down syndrome was slightly greater than that for normal subjects (57.9 +/- 5.5 degrees vs. 51.9 +/- 7.1 degrees ; P = 0.0014). A multiple logistic regression model including ICA-middle and ICA-coronal 2 provided a predictive ability of 88.1% based on the area under the receiver-operating characteristics curve. This combination had a sensitivity of 94.4% for a false-positive rate of 5% in the detection of Down syndrome.

CONCLUSIONS

Standardized iliac crest measurements of the fetal pelvis can be used to identify some fetuses at risk for trisomy 21 during the second trimester of pregnancy.

Hydrogen chromate PVC matrix membrane sensor for potentiometric determination of chromium(III) and chromium(VI) ions

A novel potentiometric Cr(6+) PVC matrix membrane sensor incorporating nickel tris(1,10-bathophenanthroline) hydrogen chromate as an electroactive material and 2-nitrophenyl phenyl ether as solvent mediator is described. In a phosphate buffer solution of pH 5, the sensor displays a rapid and linear response for Cr(6-) over the concentration range 2 x 10(-2)-8 x 10(-6) M with an anionic slope of 55.5 +/- 0.2 mV decade(-1) and a detection limit of the order of 0.4 microg ml(-1). The sensor is used for sequential determination of Cr(6+) and Cr(3+) by direct monitoring of Cr(6+) followed by oxidation of Cr(3+) and measurement of the total chromium. The average recoveries of Cr(3+) and Cr(6+) at concentration levels of 0.5-50 microg ml(-1) are 98.1 +/- 0.4% and 99.1 +/- 0.4% respectively. Redox and precipitation titrations involving Cr(6+) as a titrant are monitored with the sensor. Cr(3+) and/or Cr(6+) in wastewaters of some industries (e.g., leather tanning, electroplating, aluminum painting) and the chromium contents of some alloys and refractory bricks are assessed. The results agree fairly well with data obtained using the standard diphenylcarbazide spectrophotometric method.

A new liquid-membrane electrode for selective determination of perchlorate

A new liquid-membrane electrode which responds to perchlorate ion is described. It incorporates a 10(-2)M solution of the nitron-perchlorate ion-pair complex, in nitrobenzene, as a liquid membrane. The electrode exhibits near-Nernstian response for 10(-2)-2 x 10(-5)M perchlorate with an anionic slope of 56 mV pClO (4)). The response time is 20-90 sec, the working pH 2.5-8.5, the lower limit of detection 8 x 10(-6)M perchlorate and the selectivity for perchlorate relative to 27 inorganic and organic anions of different nature is reasonably high. Periodate, permanganate and thiocyanate, however, interfere. Determination of 2-1000 microg ml perchlorate in aqueous solutions shows an average recovery of 98.8% and a mean relative standard deviation of 1.9%. The electrode has been successfully used for direct potentiometric determination of the purity of perchlorate propellants and the solubility products of some sparingly soluble perchlorates.

Ion-selective electrodes in organic functional group analysis: microdetermination of nitrates and nitramines with use of the iodide electrode

A simple, selective and accurate method has been described for the rapid micro and submicro determination of organic nitrates and nitramines. It is based on reaction with mercury-sulphuric acid mixture for 5 min at room temperature followed by potentiometric titration of the mercurous ions released, a solid-state iodide-sensitive electrode being used. Three equivalents of potassium iodide as titrant are consumed per mole of nitrate or nitramine group. The results obtained, with sample sizes ranging from 1.0 to 50 mumole, are precise to +/- 0.2% and the average recovery is 99%. None of the other nitrogenous functional groups responds to this reaction.

Non-invasive fetal lung assessment using diffusion-weighted imaging

OBJECTIVES

The main goal was to develop a reproducible method for estimating the diffusion of water in human fetal lung tissue using diffusion-weighted imaging (DWI). A secondary objective was to determine the relationship of the apparent diffusion coefficients (ADCs) in the fetal lung to menstrual age and total lung volume.

METHODS

Normal pregnant volunteers were scanned on a 1.5-Tesla (T) magnetic resonance imaging (MRI) system. The MRI system was equipped with 40-mT/m gradients (slew rate 200 T/m/s, rise time 0.2 ms). A six-channel body array coil was used for signal reception. Single-shot DWI utilized TE/TR 125/3400 ms, slice thickness 4 mm, field of view 280 mm x 280 mm, interslice gap 0.8 mm and a matrix of 128 x 128. The voxel size was 2.5 mm x 2.5 mm x 4.0 mm. Two b-values (0 and 1000) were chosen along three orthogonal directions. ADC maps were created using assigned b-values. Simple linear regression was performed with Pearson correlation coefficient. Interexaminer and intraexaminer bias, and 95% limits of agreement (LOA) were determined using Bland-Altman plots.

RESULTS

Forty-seven scans were performed at a mean +/- SD of 29.2 +/- 4.5 weeks. The median coefficient of variation for ADC was 5.6% (interquartile range, 4.0-8.1%). No differences in ADC values were found between right and left lungs. Normally distributed ADC measurements were not significantly correlated with either total lung volume (r(2) = 0.0001, P = 0.94) or menstrual age (r(2) = 0.003, P = 0.70). The mean ADC value was 1.75 (95% CI, 1.63-1.86). Mean +/- SD intraexaminer bias was -0.15 +/- 2.3 (95% LOA, -4.7 to + 4.4) and interexaminer bias was 2.2 +/- 3.5 (95% LOA, -4.7 to + 9.1).

CONCLUSIONS

Our findings suggest that ADC measurements of the fetal lung are reproducible between blinded examiners and are independent of menstrual age, as well as lung volume.

New fetal weight estimation models using fractional limb volume

OBJECTIVES

The main goal of this study was to determine the accuracy and precision of new fetal weight estimation models, based on fractional limb volume and conventional two-dimensional (2D) sonographic measurements during the second and third trimesters of pregnancy.

METHODS

A prospective cross-sectional study of 271 fetuses was performed using three-dimensional ultrasonography to extract standard measurements-biparietal diameter (BPD), abdominal circumference (AC) and femoral diaphysis length (FDL)-plus fractional arm volume (AVol) and fractional thigh volume (TVol) within 4 days of delivery. Weighted multiple linear regression analysis was used to develop 'modified Hadlock' models and new models using transformed predictors that included soft tissue parameters for estimating birth weight. Estimated and observed birth weights were compared using mean percent difference (systematic weight estimation error) and the SD of the percent differences (random weight estimation error). The proportion of newborns with estimated birth weight within 5 or 10% of actual birth weight were compared using McNemar's test.

RESULTS

Birth weights in the study group ranged from 235 to 5790 g, with equal proportions of male and female infants. Six new fetal weight estimation models were compared with the results for modified Hadlock models with sample-specific coefficients. All the new models were very accurate, with mean percent differences that were not significantly different from zero. Model 3 (which used the natural logarithms of BPD, AC and AVol) and Model 6 (which used the natural logarithms of BPD, AC and TVol) provided the most precise weight estimations (random error = 6.6% of actual birth weight) as compared with 8.5% for the best original Hadlock model and 7.6% for a modified Hadlock model using sample-specific coefficients. Model 5 (which used the natural logarithms of AC and TVol) classified an additional 9.1% and 8.3% of the fetuses within 5% and 10% of actual birth weight and Model 6 classified an additional 7.3% and 4.1% of infants within 5% and 10% of actual birth weight.

CONCLUSION

The precision of fetal weight estimation can be improved by adding fractional limb volume measurements to conventional 2D biometry. New models that consider fractional limb volume may offer novel insight into the contribution of soft tissue development to weight estimation.

Fetal growth parameters and birth weight: their relationship to neonatal body composition

OBJECTIVES

The main goal was to investigate the relationship between prenatal sonographic parameters and birth weight in predicting neonatal body composition.

METHODS

Standard fetal biometry and soft tissue parameters were assessed prospectively in third-trimester pregnancies using three-dimensional ultrasonography. Growth parameters included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), mid-thigh circumference and femoral diaphysis length (FDL). Soft tissue parameters included fractional arm volume (AVol) and fractional thigh volume (TVol) that were derived from 50% of the humeral or femoral diaphysis lengths, respectively. Percentage of neonatal body fat (%BF) was determined within 48 h of delivery using a pediatric air displacement plethysmography system based on principles of whole-body densitometry. Correlation and stepwise multiple linear regression analyses were performed with potential prenatal predictors and %BF as the outcome variable.

RESULTS

Eighty-seven neonates were studied with a mean +/- SD %BF of 10.6 +/- 4.6%. TVol had the greatest correlation with newborn %BF of all single-parameter models. This parameter alone explained 46.1% of the variability in %BF and the best stepwise multiple linear regression model was: %BF = 0.129 (TVol) - 1.03933 (P < 0.001). Birth weight similarly explained 44.7% of the variation in %BF. AC and estimated fetal weight (EFW) accounted for only 24.8% and 30.4% of the variance in %BF, respectively. Skeletal growth parameters, such as FDL (14.2%), HC (7.9%) and BPD (4.0%), contributed the least towards explaining the variance in %BF.

CONCLUSIONS

During the late third trimester of pregnancy %BF is most highly correlated with TVol. Similar to actual birth weight, this soft tissue parameter accounts for a significant improvement in explaining the variation in neonatal %BF compared with fetal AC or EFW alone.

Fractional limb volume--a soft tissue parameter of fetal body composition: validation, technical considerations and normal ranges during pregnancy

OBJECTIVES

The main goals were to provide normal reference ranges for fractional limb volume as a new index of generalized fetal nutritional status, to evaluate the reproducibility of fractional fetal limb volume measurements during the second and third trimesters of pregnancy, and to demonstrate technical considerations for this technique.

METHODS

This was a prospective, cross-sectional study of gravid women during mid to late pregnancy. Fractional limb volumes were based on either 50% of humeral or femoral diaphysis length. Each partial volume was subdivided into five equidistant slices that were centered along the mid-arm or mid-thigh. Slices were traced manually to obtain fractional arm (AVol) or fractional thigh (TVol) volume. Reproducibility studies were performed, using Bland-Altman plots, to assess blinded interobserver and intraobserver measurement bias and agreement. Selected images were chosen to demonstrate technical factors for the acquisition and analysis of these parameters. Reference charts were established to describe normal ranges for AVol and TVol.

RESULTS

Three hundred and eighty-seven subjects were scanned to include 380 AVol (range, 1.1-68.3 mL) and 378 TVol (range 2.0-163.2 mL) measurements between 18.0 and 42.1 weeks' menstrual age. No gender differences were found in these soft tissue measurements (AVol, P = 0.90; TVol, P = 0.91; Mann-Whitney test). Intraobserver mean bias +/- SD and 95% limits of agreement (LOA) for fractional limb volumes were: 2.2 +/- 4.2% (95% LOA, - 6.0 to 10.5%) for AVol and 2.0 +/- 4.2% (95% LOA, - 6.3 to 10.3%) for TVol. Interobserver bias and agreement were - 1.9 +/- 4.9% (95% LOA, - 11.6 to 7.8%) for AVol and - 2.0 +/- 5.4% (95% LOA, - 12.5 to 8.6%) for TVol. Technical factors were related to image optimization, transducer pressure, fetal movement, soft tissue compression and amniotic fluid volume.

CONCLUSIONS

Fractional limb volume assessment may improve the detection and monitoring of malnourished fetuses because this soft tissue parameter can be obtained quickly and reproducibly during mid to late pregnancy. Careful attention should be placed on technical factors that can potentially affect optimal acquisition and analysis of these volume measurements.

Adiponectin multimers in maternal plasma

OBJECTIVE

Adiponectin is an anti-diabetic, anti-atherogenic, anti-inflammatory, and angiogenic adipokine that circulates in oligomeric complexes including: low molecular weight (LMW) trimers, medium molecular weight (MMW) hexamers, and high molecular weight (HMW) isoforms. The aim of this study was to determine whether there are changes in adiponectin multimers in pregnancy and as a function of maternal weight.

STUDY DESIGN

In this cross-sectional study, plasma concentrations of total, HMW, MMW, and LMW adiponectin were determined in women included in three groups: (1) normal pregnant women of normal body mass index (BMI) (n = 466), (2) overweight pregnant women (BMI >or=25; n = 257), and (3) non-pregnant women of normal weight (n = 40). Blood samples were collected once from each woman between 11 and 42 weeks of gestation. Plasma adiponectin multimer concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

RESULTS

(1) The median HMW adiponectin concentration and the median HMW/total adiponectin ratio were significantly higher, and the median LMW adiponectin concentration was significantly lower in pregnant women than in non-pregnant women. (2) Among pregnant women, the median plasma concentration of total, HMW, and MMW adiponectin was significantly higher in normal weight women than in overweight patients. (3) Maternal HMW was the most prevalent adiponectin multimer regardless of gestational age or BMI status. (4) There were no significant differences in the median concentration of total, MMW, and LMW adiponectin and their relative distribution with advancing gestation.

CONCLUSION

Human pregnancy is characterized by quantitative and qualitative changes in adiponectin multimers, especially the most active isoform, HMW adiponectin.

Expression patterns of microRNAs in the chorioamniotic membranes: a role for microRNAs in human pregnancy and parturition

MicroRNAs (miRNAs) are involved in the post-transcriptional regulation of gene expression during development. This study was performed to determine gestational age-dependent changes in miRNA expression in the chorioamniotic membranes and to assess the significance of miRNAs in human pregnancy and parturition. The expression profile of 455 miRNAs was compared between patients at term without labour (TNL: n = 10), in labour (TL: n = 10), and preterm labour (PTL: n = 10) using microarrays. A total of 39 miRNAs were differentially expressed between term and preterm cases, of which 31 (79.5%) were down-regulated at term. Expression of ten miRNAs, including miR-338, differentially expressed between PTL and TL groups was decreased at term. Computational analyses using miRBase Targets have identified PLA2G4B, a phospholipase implicated in parturition, as a putative target of miR-338. Inhibition of endogenous miR-338 with anti-miR-338 increased the mRNA and protein expression of PLA2G4B in decidual cells. Luciferase assay with reporter constructs confirmed that the suppression of PLA2G4B occurs through binding of miR-338 to the 3UTR of PLA2G4B. Interestingly, the expression of Dicer, a key miRNA-processing enzyme, was markedly decreased at term, particularly with labour in the chorioamniotic membranes. Collectively, the novel findings reported herein strongly suggest that post-transcriptional regulation of genes by miRNAs, coupled with the changes of miRNA processing machinery in the chorioamniotic membranes, plays a role in pregnancy and parturition. Furthermore, the expression level of Dicer in the chorioamniotic membranes dichotomizes pathological preterm labour and physiological spontaneous labour at term.

Detection of H5, H7 and H9 subtypes of avian influenza viruses by multiplex reverse transcription-polymerase chain reaction

Subtype-specific multiplex reverse transcription-polymerase chain reaction (RT-PCR) was developed to simultaneously detect three subtypes (H5, H7 and H9) of avian influenza virus (AIV) type A. The sensitivity of the multiplex RT-PCR was evaluated and compared to that of RT-PCR-enzyme-linked immunosorbent assay (ELISA) and conventional RT-PCR. While the sensitivity of the multiplex RT-PCR is as sensitive as the conventional RT-PCR, it is 10 times less sensitive than RT-PCR-ELISA. The multiplex RT-PCR is also as sensitive as the virus isolation method in detecting H9N2 from tracheal samples collected at day 3 and 5 post inoculation. Hence, the developed multiplex RT-PCR assay is a rapid, sensitive and specific assay for detecting of AIV subtypes.

The effect of gestational age and labor on placental growth hormone in amniotic fluid

OBJECTIVE

Placental growth hormone (PGH) is produced by trophoblast. This hormone becomes detectable in maternal serum during the first trimester of pregnancy. Its concentration increases as term approaches and becomes undetectable within one hour of delivery. PGH has important biological properties, including somatogenic (growth promotion), lactogenic, and lipolytic activity. Recently, PGH has been detected in amniotic fluid (AF) of midtrimester pregnancies. The purpose of this study was to determine whether PGH concentrations in AF change with advancing gestational age and in labor at term.

DESIGN

AF was assayed for PGH concentrations in samples obtained from patients undergoing genetic amniocentesis between 14 and 18 weeks of gestation (n=67), normal patients at term not in labor (n=24), and pregnant women at term in labor (n=51). PGH concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

(1) PGH was detected in all AF samples; (2) patients in the midtrimester had a higher median concentration of PGH in AF than those at term (midtrimester: median: 3140.5 pg/ml; range: 1124.2-13886.5 vs. term: median: 2021.1pg/ml; range: 181.6-8640.8; p<0.01); (3) there was no difference in the median concentration of PGH between women at term, not in labor, and those in labor (term not in labor: median: 2113.4pg/ml; range: 449.3-8640.8 vs. term in labor: median: 2004.1pg/ml; range: 181.6-8531.5; p=0.73).

CONCLUSIONS

(1) PGH is detectable in AF at both mid- and third trimesters; (2) the median AF concentration of PGH is significantly lower at term when compared to the second trimester; (3) labor at term is not associated with changes in the AF concentration of PGH. The role of this unique placental hormone now found in the fetal compartment requires further investigation.

Relationship between casual blood sugar and body mass index in a suburban northern Nigerian population: A short communication

BACKGROUND

Obesity is the most important modifiable risk factor in the pathogenesis of type-2 diabetes reported in most cross sectional studies. However, racial factors seem to be important in the relationship between body mass index (BMI) and glucose intolerance. This study aims at defining the relationship between these variables in two suburban populations in Nigeria.

METHOD

A prospective survey of Adults aged 55 years or younger who gave informed consent, in two communities (Makarfi and Giwa) near Zaria, northern Nigeria was done. The BMI and casual blood sugar using capillary blood assessed with the Ames glucometer were determined for all the subjects. Students t-test was used to compare continuous variables while Pearson's correlation coefficient was used for continuous variables; the level of significance was p < 0.05 in each case.

RESULT

Three-hundred and seventeen subjects participated in the study Mean age of subjects was 35.03 +/- 9.79 years (33.0 +/- 9.64 among females and 36.18 +/- 9.59 among males p = 0.1007).

CONCLUSION

Female subjects had significantly higher BMI than their male counter parts, (26.61 +/- 7.19 KgM2 versus 24.01 +/- 5.39, KgM2 p = 0.0341.) Casual blood sugar levels were however similar between males and females 85.21 +/-27.04 mg/dl versus 85.88 +/- 14.74 mg/dl, p = 0.8868. There was a positive but non-significant correlation between casual blood sugar and BMI among female subjects (r = +0.1520, p > 0.05) in the males however, the correlation between these variables was not significant (r = -0.0395, p > 0.5).

Reverse transcriptase-polymerase chain reaction-enzyme linked immunosorbent assay for rapid detection of avian influenza virus subtype H9N2

The performance of a simplified nucleoprotein (NP) and hemagglutinin-subtype-9 (H9) based reverse transcriptase-polymerase chain reaction-enzyme linked immunosorbent assay (RT-PCR-ELISA) for the detection of avian influenza virus (AIV) subtype H9N2 was compared to the standard the virus isolation method and serology testing using hemagglutination (HA) and hemagglutination inhibition (HI) tests. The H9-based RT-PCR-ELISA was 100% sensitive when compared to virus isolation method in detecting H9N2 from experimentally infected specific-pathogen-free (SPF) chickens. The NP- and H9-based RT-PCR-ELISA have a detection limit similar to the virus isolation method in detecting serially diluted tracheal swab samples obtained from chickens inoculated with H9N2. Both RT-PCR-ELISAs were also ten times more sensitive than agarose gel electrophoresis for the detection of PCR products. The result of this study demonstrate that the developed RT-PCR-ELISA is a simple and sensitive assay for the detection of type A influenza virus, particularly AIV subtype H9N2, in chickens.

Evolution and adaptation of H5N1 influenza virus in avian and human hosts in Indonesia and Vietnam

Highly pathogenic avian influenza virus H5N1 is endemic in poultry in East and Southeast Asia with disease outbreaks recently spreading to parts of central Asia, Europe and Africa. Continued interspecies transmission to humans has been reported in Vietnam, Thailand, Cambodia, Indonesia and China, causing pandemic concern. Here, we genetically characterize 82 H5N1 viruses isolated from poultry throughout Indonesia and Vietnam and 11 human isolates from southern Vietnam together with sequence data available in public databases to address questions relevant to virus introduction, endemicity and evolution. Phylogenetic analysis shows that all viruses from Indonesia form a distinct sublineage of H5N1 genotype Z viruses suggesting this outbreak likely originated from a single introduction that spread throughout the country during the past two years. Continued virus activities in Indonesia were attributed to transmission via poultry movement within the country rather than through repeated introductions by bird migration. Within Indonesia and Vietnam, H5N1 viruses have evolved over time into geographically distinct groups within each country. Molecular analysis of the H5N1 genotype Z genome shows that only the M2 and PB1-F2 genes were under positive selection, suggesting that these genes might be involved in adaptation of this virus to new hosts following interspecies transmission. At the amino acid level 12 residues were under positive selection in those genotype Z viruses, in the HA and PB1-F2 proteins. Some of these residues were more frequently observed in human isolates than in avian isolates and are related to viral antigenicity and receptor binding. Our study provides insight into the ongoing evolution of H5N1 influenza viruses that are transmitting in diverse avian species and at the interface between avian and human hosts.

Thoracoscopic management of malignant pleural effusion: technique, complications and prevention

In 1910, Professor H. C. Jacobaeus first described thoracoscopy. He used a modified cystoscope to inspect the pleural cavity. He described his two cannula techniques, one for the light source, and the other for viewing. Later on, the technique was improved, and a single cannula provided the light source and an optic telescope. With the advent of video assisted thoracoscopy, the procedure has gone full circle; once again, two cannulae are used - one to give us a video assisted telescopic picture and the second cannula is used for operational purposes.

Relationship between fetal pulmonary maturity assessment and neonatal outcome in premature rupture of the membranes at 32-34 weeks' gestation

The absence of fetal pulmonary maturity in patients with preterm premature rupture of the membranes (PPROM) is often considered an indication for conservative management. The purpose of this study was to examine the value of biochemical pulmonary maturity assessment for the prediction of neonatal outcome in patients with PPROM between 32 and 34 weeks' gestation. Pregnancies complicated by PPROM at 32 to 34 weeks' gestation that delivered from January 1995 to May 2000 and had biochemical pulmonary maturity assessment were reviewed. Patients with medical disorders, multiple gestations, fetal growth restriction or structural anomalies, or evidence of intra-amniotic infection were excluded. Neonatal outcome measures were compared between patients with mature and immature pulmonary indices. During this time period, 244 patients with PPROM at 32-34 weeks' gestation were delivered; 78 patients met inclusion criteria (n = 41 patients with mature indices and n = 37 patients with immature indices). There were no cases of perinatal death or sepsis. There was no difference in major neonatal morbidities including need for mechanical ventilation, grade 2 or 3 necrotizing enterocolitis, grade 3 or 4 intraventricular hemorrhage, or seizures. After controlling for confounding factors including gestational age at PPROM and delivery, latency period, group B streptococcus (GBS) vaginal colonization, corticosteroid therapy, neonatal sex, mode of delivery, fetal indications for delivery, and umbilical cord pH, biochemical pulmonary maturity was not predictive of major neonatal morbidity. In our population, biochemical pulmonary maturity status does not appear to be predictive of neonatal morbidity in pregnancies complicated by PPROM at 32-34 weeks' gestation.

Effects of intrapartum zidovudine therapy on fetal heart rate parameters in women with human immunodeficiency virus infection

OBJECTIVE

To determine the effects of intrapartum maternal administration of zidovudine on fetal heart rate (FHR) parameters in women infected with the human immunodeficiency virus (HIV).

METHODS

Term HIV-infected women who delivered at our institution (1995-1998) were identified by medical records coding. Sixty minutes of FHR tracing prior to zidovudine administration and 60 min of FHR tracing 2 h after initiation of therapy were reviewed by 3 perinatologists blinded to patient status. Data were compared with paired t tests; p < 0.05 was considered significant. Inter- and intra-observer FHR interpretation variation were calculated.

RESULTS

Ten patients met study criteria. Their demographic data included: Maternal age 26.5 +/- 6.5 years, gestational age 38.9 +/- 1.3 weeks, median parity 2 (range 0-3). Eighty percent were African American. There were no significant differences in FHR parameters after intravenous zidovudine therapy (pretreatment versus 2 h after treatment) with respect to FHR baseline (p = 0.2), FHR variability (p = 0.3), or the number of accelerations (p = 0.1). There was also no difference in the number of variable (moderate or severe), early, or prolonged decelerations following zidovudine infusion.

CONCLUSION

Two hours of continuous intrapartum intravenous infusion of zidovudine does not alter any parameter of the FHR in the laboring HIV-infected gravida.