Quantitative 3D Characterization for Kinetics of Corrosion Initiation and Propagation in Additively Manufactured Austenitic Stainless Steel

In situ X-ray computed tomography (X-ray CT) is used to investigate the effects of characteristic microstructural features on the pitting initiation and propagation in austenitic stainless steel specimens prepared with laser powder bed fusion (LPBF) additive manufacturing. In situ X-ray CT in probing the mechanism and kinetics of localized corrosion is demonstrated by immersing two LPBF specimens with different porosities in an aggressive ferric chloride solution for the evaluation of corrosion. X-ray CT images are acquired from the specimens after every 8 hours of immersion over an extended period of time (216 hours). Corrosion pit growth is then quantitatively analyzed with a data-constrained modeling method. The pitting growth mechanism of LPBF stainless steel is found to be different from that of conventional stainless steels. More specifically, the mechanism of corrosion pit initiation is closely correlated with the original lack of fusion porosity (LOF) distribution on the surface of the specimens and preferential pit propagation through the LOF pores inside the specimens. Pit growth kinetics are derived from pit volume changes determined through 3D data analysis. The pit growth kinetics in LPBF specimens are found to vary in the initial pit formation, competitive pit propagation, and the dominant pit growth stages.

In Situ Investigation of Under-Deposit Microbial Corrosion and its Inhibition Using a Multi-Electrode Array System

Carbon steel pipelines used in the oil and gas industry can be susceptible to the combined presence of deposits and microorganisms, which can result in a complex phenomenon, recently termed under-deposit microbial corrosion (UDMC). UDMC and its inhibition in CO₂ ambiance were investigated in real-time using a multi-electrode array (MEA) system and surface profilometry analysis. Maps from corrosion rates, galvanic currents, and corrosion potentials recorded at each microelectrode allowed the visualization of local corrosion events on the steel surface. A marine bacterium Enterobacter roggenkampii, an iron-oxidizing, nitrate-reducing microorganism, generated iron deposits on the surface that resulted in pitting corrosion under anaerobic conditions. Areas under deposits displayed anodic behavior, more negative potentials, higher corrosion rates, and pitting compared to areas outside deposits. In the presence of the organic film-forming corrosion inhibitor, 2-Mercaptopyrimidine, the marine bacterium induced local breakdown of the protective inhibitor film and subsequent pitting corrosion of carbon steel. The ability of the MEA system to locally measure self-corrosion processes, galvanic effects and, corrosion potentials across the surface demonstrated its suitability to detect, evaluate and monitor the UDMC process as well as the efficiency of corrosion inhibitors to prevent this corrosion phenomenon. This research highlights the importance of incorporating the microbial component to corrosion inhibitors evaluation to ensure chemical effectiveness in the likely scenario of deposit formation and microbial contamination in oil and gas production equipment.

Screening for pre-eclampsia by maternal factors and biomarkers at 11-13 weeks' gestation

OBJECTIVE

To examine the performance of screening for early, preterm and term pre-eclampsia (PE) at 11-13 weeks' gestation by maternal factors and combinations of mean arterial pressure (MAP), uterine artery (UtA) pulsatility index (PI), serum placental growth factor (PlGF) and serum pregnancy-associated plasma protein-A (PAPP-A).

METHODS

The data for this study were derived from three previously reported prospective non-intervention screening studies at 11 + 0 to 13 + 6 weeks' gestation in a combined total of 61 174 singleton pregnancies, including 1770 (2.9%) that developed PE. Bayes' theorem was used to combine the prior distribution of gestational age at delivery with PE, obtained from maternal characteristics, with various combinations of biomarker multiples of the median (MoM) values to derive patient-specific risks of delivery with PE at < 37 weeks' gestation. The performance of such screening was estimated.

RESULTS

In pregnancies that developed PE, compared to those without PE, the MoM values of UtA-PI and MAP were increased and those of PAPP-A and PlGF were decreased, and the deviation from normal was greater for early than late PE for all four biomarkers. Combined screening by maternal factors, UtA-PI, MAP and PlGF predicted 90% of early PE, 75% of preterm PE and 41% of term PE, at a screen-positive rate of 10%; inclusion of PAPP-A did not improve the performance of screening. The performance of screening depended on the racial origin of the women; on screening by a combination of maternal factors, MAP, UtA-PI and PlGF and using a risk cut-off of 1 in 100 for PE at < 37 weeks in Caucasian women, the screen-positive rate was 10% and detection rates for early, preterm and term PE were 88%, 69% and 40%, respectively. With the same method of screening and risk cut-off in women of Afro-Caribbean racial origin, the screen-positive rate was 34% and detection rates for early, preterm and term PE were 100%, 92% and 75%, respectively.

CONCLUSION

Screening by maternal factors and biomarkers at 11-13 weeks' gestation can identify a high proportion of pregnancies that develop early and preterm PE. © 2018 Crown copyright. Ultrasound in Obstetrics & Gynecology © 2018 ISUOG.

Prediction and prevention of small-for-gestational-age neonates: evidence from SPREE and ASPRE

OBJECTIVES

To examine the effect of first-trimester screening for pre-eclampsia (PE) on the prediction of delivering a small-for-gestational-age (SGA) neonate and the effect of prophylactic use of aspirin on the prevention of SGA.

METHODS

The data for this study were derived from two multicenter studies. In SPREE, we investigated the performance of screening for PE by a combination of maternal characteristics and biomarkers at 11-13 weeks' gestation. In ASPRE, women with a singleton pregnancy identified by combined screening as being at high risk for preterm PE (> 1 in 100) participated in a trial of aspirin (150 mg/day from 11-14 until 36 weeks' gestation) compared to placebo. In this study, we used the data from the ASPRE trial to estimate the effect of aspirin on the incidence of SGA with birth weight < 10^th , < 5^th and < 3^rd percentile for gestational age. We also used the data from SPREE to estimate the proportion of SGA in the pregnancies with a risk for preterm PE of > 1 in 100.

RESULTS

In SPREE, screening for preterm PE by a combination of maternal factors, mean arterial pressure, uterine artery pulsatility index and serum placental growth factor identified a high-risk group that contained about 46% of SGA neonates < 10^th percentile born at < 37 weeks' gestation (preterm) and 56% of those born at < 32 weeks (early); the overall screen-positive rate was 12.2% (2014 of 16 451 pregnancies). In the ASPRE trial, use of aspirin reduced the overall incidence of SGA < 10^th percentile by about 40% in babies born at < 37 weeks' gestation and by about 70% in babies born at < 32 weeks; in babies born at ≥ 37 weeks, aspirin did not have a significant effect on incidence of SGA. The aspirin-related decrease in incidence of SGA was mainly due to its incidence decreasing in pregnancies with PE, for which the decrease was about 70% in babies born at < 37 weeks' gestation and about 90% in babies born at < 32 weeks. On the basis of these results, it was estimated that first-trimester screening for preterm PE and use of aspirin in the high-risk group would potentially reduce the incidence of preterm and early SGA by about 20% and 40%, respectively.

CONCLUSION

First-trimester screening for PE by the combined test identifies a high proportion of cases of preterm SGA that can be prevented by the prophylactic use of aspirin. © 2018 Crown copyright. Ultrasound in Obstetrics & Gynecology © 2018 ISUOG.

ASPRE trial: incidence of preterm pre-eclampsia in patients fulfilling ACOG and NICE criteria according to risk by FMF algorithm

OBJECTIVE

To report the incidence of preterm pre-eclampsia (PE) in women who are screen positive according to the criteria of the National Institute for Health and Care Excellence (NICE) and the American College of Obstetricians and Gynecologists (ACOG), and compare the incidence with that in those who are screen positive or screen negative by The Fetal Medicine Foundation (FMF) algorithm.

METHODS

This was a secondary analysis of data from the ASPRE study. The study population consisted of women with singleton pregnancy who underwent prospective screening for preterm PE by means of the FMF algorithm, which combines maternal factors and biomarkers at 11-13 weeks' gestation. The incidence of preterm PE in women fulfilling the NICE and ACOG criteria was estimated; in these patients the incidence of preterm PE was then calculated in those who were screen negative relative to those who were screen positive by the FMF algorithm.

RESULTS

A total of 34 573 women with singleton pregnancy delivering at ≥ 24 weeks' gestation underwent prospective screening for preterm PE, of which 239 (0.7%) cases developed preterm PE. At least one of the ACOG criteria was fulfilled in 22 287 (64.5%) pregnancies and the incidence of preterm PE was 0.97% (95% CI, 0.85-1.11%); in the subgroup that was screen positive by the FMF algorithm the incidence of preterm PE was 4.80% (95% CI, 4.14-5.55%), and in those that were screen negative it was 0.25% (95% CI, 0.18-0.33%), with a relative incidence in FMF screen negative to FMF screen positive of 0.051 (95% CI, 0.037-0.071). In 1392 (4.0%) pregnancies, at least one of the NICE high-risk criteria was fulfilled, and in this group the incidence of preterm PE was 5.17% (95% CI, 4.13-6.46%); in the subgroups of screen positive and screen negative by the FMF algorithm, the incidence of preterm PE was 8.71% (95% CI, 6.93-10.89%) and 0.65% (95% CI, 0.25-1.67%), respectively, and the relative incidence was 0.075 (95% CI, 0.028-0.205). In 2360 (6.8%) pregnancies fulfilling at least two of the NICE moderate-risk criteria, the incidence of preterm PE was 1.74% (95% CI, 1.28-2.35%); in the subgroups of screen positive and screen negative by the FMF algorithm the incidence was 4.91% (95% CI, 3.54-6.79%) and 0.42% (95% CI, 0.20-0.86%), respectively, and the relative incidence was 0.085 (95% CI, 0.038-0.192).

CONCLUSION

In women who are screen positive for preterm PE by the ACOG or NICE criteria but screen negative by the FMF algorithm, the risk of preterm PE is reduced to within or below background levels. The results provide further evidence to support the personalized risk-based screening method that combines maternal factors and biomarkers. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

[Effects of exogenous high mobility group protein box 1 on angiogenesis in ischemic zone of early scald wounds of rats]

Objective: To observe effects of exogenous high mobility group protein box 1 (HMGB1) on angiogenesis in ischemic zone of early scald wounds of rats. Methods: Thirty-six Sprague-Dawley rats were divided into HMGB1 group and simple scald (SS) group according to the random number table, with 18 rats in each group. Comb-like copper mould was placed on the back of rats for 20 s after being immersed in 100 ℃ hot water for 3 to 5 min to make three ischemic zones of wound. Immediately after scald, rats in HMGB1 group were subcutaneously injected with 0.4 μg HMGB1 and 0.1 mL phosphate buffer solution (PBS), and rats in SS group were subcutaneously injected with 0.1 mL PBS from boarders of ischemic zone of scald wound. At post scald hour (PSH) 24, 48, and 72, 6 rats in each group were collected. Protein expressions of vascular endothelial growth factor (VEGF) in ischemic zone of wound at PSH 24, 48, and 72 and protein expressions of CD31 in ischemic zone of wound at PSH 48 and 72 were detected by immunohistochemistry. The number of microvessel in CD31 immunohistochemical sections of ischemic zone of wound at PSH 48 and 72 was calculated after observing by the microscope. The mRNA expressions of VEGF and CD31 in ischemic zone of wound were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction at PSH 24, 48, and 72. Data were processed with analysis of variance of factorial design, t test, and Bonferroni correction. Results: (1) At PSH 24, 48, and 72, protein expressions of VEGF in ischemic zone of wound of rats in HMGB1 group were significantly higher than those of rats in SS group (t=7.496, 4.437, 5.402, P<0.05 or P<0.01). At PSH 48 and 72, protein expressions of CD31 in ischemic zone of wound of rats in HMGB1 group were 0.038 8±0.007 9 and 0.057 7±0.001 2 respectively, significantly higher than 0.013 4±0.004 9 and 0.030 3±0.004 0 of rats in SS group (t=10.257, 15.055, P<0.01). (2) At PSH 48 and 72, the number of microvessel in ischemic zone of wound of rats in HMGB1 group was obviously more than that of rats in SS group (t=3.536, 4.000, P<0.05). (3) At PSH 24, 48, and 72, mRNA expressions of VEGF in ischemic zone of wound of rats in HMGB1 group were significantly higher than those of rats in SS group (t=4.406, 3.821, 3.356, P<0.05). At PSH 24 and 48, mRNA expressions of CD31 in ischemic zone of wound of rats in HMGB1 group were significantly higher than those of rats in SS group (t=4.113, 3.466, P<0.05). At PSH 72, mRNA expressions of CD31 in ischemic zone of wound of rats in 2 groups were close (t=0.010, P>0.05). Conclusions: Exogenous HMGB1 can promote angiogenesis in ischemic zone of early scald wounds of rats by increasing expressions of VEGF and CD31.

Protocol for the prospective validation study: 'Screening programme for pre-eclampsia' (SPREE)

Pre-eclampsia (PE), which affects about 2% of pregnancies, is a major cause of maternal and perinatal morbidity and mortality. Early detection of PE can improve pregnancy outcome by providing timely intervention and closer monitoring. The current guideline from the UK National Institute for Health and Care Excellence (NICE) recommends that, at the booking visit, women identified with one major risk factor or more than one moderate risk factor for PE should be advised to take low-dose aspirin daily from 12 weeks until delivery. However, performance of the current method of screening is poor and identifies only about 35% of PE. Extensive studies in the last decade have established that the best performance for early prediction of PE can be achieved by using a novel Bayes' theorem-based method that combines maternal characteristics and medical history together with measurements of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A) at 11-13 weeks' gestation. This forms the 'combined test', which could be simplified to the 'mini combined test' when only maternal factors, MAP and PAPP-A are taken into consideration. We present the protocol (version 3.1, 14 November 2016) for the 'Screening programme for pre-eclampsia' (SPREE) study, a prospective multicenter cohort study that will be carried out in seven National Health Service maternity hospitals in England. Eligible pregnant women attending their routine scan at 11-13 weeks' gestation will be invited to participate in this study. Maternal characteristics and history and measurements of MAP, UtA-PI, serum PAPP-A and PlGF will be recorded according to standardized protocols. The patient-specific risk for PE will be calculated and data on pregnancy outcomes collected. We hypothesize that the first-trimester mini combined test and combined test for PE screening, using the Bayes' theorem-based method, are likely to be superior to the current method recommended by NICE that is based on maternal demographics and history alone. Enrollment for the study commenced in April 2016. The study is registered on the International Standard Randomised Controlled Trial Number (ISRCTN) registry. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

[Genetic analysis of TPO, DUOX2 and DUOXA2 genes in children with permanent congenital hypothyroidism suspected dyshormonogenesis]

Objective: To explore the TPO, DUOX2 and DUOXA2 genotypes and phenotypes of children with permanent congenital hypothyroidism(PCH) suspected dyshormonogenesis in Guangzhou, identified and treated at Guangzhou Newborn Screening Center. Six of them were born between 2011 and 2012. Method: Retrospectively analyzed the clinical data of 9 children with PCH suspected dyshormonogenesis. Genetic analysis of TPO, DUOX2 and DUOXA2 genes were performed with Sanger sequencing. Result: Of the 9 patients, four were identified variants in TPO gene including three cases with biallelic variants and one case with monoallelic variant. Novel c. 1784G>C( p. R595T) variant in TPO was predicted to be damaging by SIFT and PolyPhen-2. Four patients harbored monoallelic known variants in DUOX2 gene and the other one harbored heterozygous known mutation c. 738C>G(p.Y246X) in DUOXA2 gene.Two adolescent patients with biallelic variants in TPO gene showed classical PCH phenotypes with thyroid goiter or nodules. The six patients with monoallelic variant in TPO, DUOX2 or DUOXA2 presented variable phenotypes. Among the 433 578 newborns in the 2011-2012 cohort, there were 156 cases of CH. Six of these cases were PCH suspected dyshormonogenesis, among which 1 case was confirmed TPO biallelic variants and 5 cases were monoallelic variants of TPO, DUOX2, or DUOXA2 genes. Conclusion: TPO and DUOX2 variants are the common molecular pathogenesis in children with PCH suspected dyshormonogenesis. Monoallelic variants in TPO, DUOX2 or DUOXA2 are associated with PCH and showed wide variability in their phenotypes. The novel variant p. R595T in TPO is probably a pathologic variant. The prevalence of PCH caused by TPO gene defects is rare in Guangzhou.

Comparison of screening for pre-eclampsia at 31-34 weeks' gestation by sFlt-1/PlGF ratio and a method combining maternal factors with sFlt-1 and PlGF

OBJECTIVE

To estimate the patient-specific risk of pre-eclampsia (PE) at 31-34 weeks' gestation by a combination of maternal characteristics and medical history with multiples of the median (MoM) values of serum placental growth factor (PlGF) and serum soluble fms-like tyrosine kinase-1 (sFlt-1) and to compare the performance of screening to that achieved by the sFlt-1/PlGF ratio.

METHODS

This was a prospective observational study in women attending a third-trimester ultrasound scan at 31-34 weeks as part of routine pregnancy care. We estimated the performance of screening for PE with delivery within 4 weeks of assessment and PE with delivery from 4 weeks after assessment up to 40 weeks' gestation by the sFlt-1/PlGF ratio and by a method utilizing Bayes' theorem that combines maternal factors and MoM values of sFlt-1 and PlGF. The significance of the difference in screening performance between the two methods was assessed by comparison of the areas under the receiver-operating characteristics curves (AUC).

RESULTS

The study population of 8063 singleton pregnancies included 231 (2.9%) that subsequently developed PE. In the prediction of delivery with PE at < 4 weeks from assessment, the performance of the method utilizing Bayes' theorem was similar to that using the sFlt-1/PlGF ratio (AUC, 0.987 (95% CI, 0.979-0.995) vs 0.988 (95% CI, 0.981-0.994); P = 0.961). In contrast, the performance of screening for delivery with PE at ≥ 4 weeks after assessment up to 40 weeks' gestation was better with the method utilizing Bayes' theorem than that with the sFlt-1/PlGF ratio (AUC, 0.884 (95% CI, 0.854-0.914) vs 0.818 (95% CI, 0.775-0.860); P < 0.0001).

CONCLUSION

At 31-34 weeks' gestation the performance of screening for PE delivering at < 4 weeks from assessment by the method utilizing Bayes' theorem is similar to that using the sFlt-1/PlGF ratio, but the former is superior to the latter in prediction of PE delivering ≥ 4 weeks from assessment. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Birth weight in live births and stillbirths

OBJECTIVE

To establish a normal range of birth weights for gestational age at delivery and to compare the proportion of live births and stillbirths that are classified as small-for-gestational age (SGA) according to our normal range vs that of the INTERGROWTH-21^st standard.

METHODS

The study population comprised 113 019 live births and 437 (0.4%) stillbirths. The inclusion criterion for establishing a normal range of birth weights for gestational age was the live birth of a phenotypically normal neonate ≥ 24 weeks' gestation and the exclusion criteria were smoking and prepregnancy hypertension, diabetes mellitus, systemic lupus erythematosus or antiphospholipid syndrome, pre-eclampsia, gestational hypertension, gestational diabetes mellitus or iatrogenic preterm birth for fetal growth restriction in the current pregnancy. Inclusion criteria were met by 92 018 live births. The proportions of live births and stillbirths with birth weights < 5^th and < 10^th percentiles of our normal range and those according to the INTERGROWTH-21^st standard were determined and compared by the chi-square test and McNemar test.

RESULTS

The proportions of live births and stillbirths with a birth weight < 5^th percentile according to our standard were significantly higher than and discordant with the proportion according to the INTERGROWTH-21^st standard (live birth: 5.6% vs 3.4%; stillbirth: 37.2% vs 22.7%). Similarly, the proportion of live births and stillbirths with a birth weight < 10^th percentile according to our standard were significantly higher than and discordant with those according to the INTERGROWTH-21^st standard (live birth: 11.2% vs 6.9%; stillbirth: 44.3% vs 32.6%).

CONCLUSION

The INTERGROWTH-21^st standard underestimates the proportion of SGA live births and stillbirths in our population. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Abstract P4-02-06: Improving efficacy of applying breast MRI to detect mammography-occult breast cancer

Background: Mammography is the only clinically acceptable imaging modality in current population-based breast cancer screening, but it has a relatively low sensitivity in detecting early cancers. Although breast magnetic resonance imaging (MRI) is much more sensitive in detecting early or mammography-occult cancers, the low cancer detection yield in the general screening population (∼1%) prohibits breast MRI as a screening tool with wide applicability. In order to solve this clinical dilemma, in this preliminary study, we tested the potential of applying a new mammographic image feature analysis model that serves as a short-term breast cancer risk prediction model to identify women at high risk of harboring mammography-occult breast cancers, which can be detected by breast MRI.

Methods: An image dataset involving 30 women who had both mammography and breast MRI screening examinations was retrospectively assembled. All mammograms were interpreted as negative by the radiologists during the original image interpretation. When applying breast MRI examinations to these women immediately following the negative mammography, 5 women were positive with cancer detected and 25 remained negative. We developed a computer-aided detection scheme to process the bilateral CC view mammograms of the left and right breasts. Ten (10) texture-based mammographic image features were computed and compared from the bilateral mammograms. These features were then fused to build a new artificial neural network (ANN) based risk model. Based on the threshold of 0.5 applying to the ANN-generated risk prediction scores (ranging from 0 to 1), we stratified these 30 women into two groups with high and low risk of harboring mammography-occult cancer.

Results: Using the ANN-generated risk scores, 9 and 21 cases were assigned to high-risk and low-risk group, respectively. All 5 breast MRI-detected cancer cases were classified into the high-risk group (with 100% sensitivity), while 4 negative cases were also classified into the high-risk group resulting in a 16% false-positive rate (4/25). All 21 cases in the low-risk group were negative cases. Hence, our risk prediction model yielded an overall prediction accuracy of 86.7% in which 26 of 30 cases were correctly classified. The potential clinical impact is that based on the case stratification result, the maximum cancer detection yield of using breast MRI is 56% (5/9) in this dataset. Meanwhile, it can also eliminate 84% (21/25) unnecessary (negative) breast MRI screening examinations.

Conclusions: This is the first study, which demonstrated that by computing and analyzing the variation of mammographic image features, we are able to develop a new quantitative image feature analysis model that can be applied to predict the short-term risk of a woman having a mammography-occult cancer that can be detected by breast MRI. This new strategy has the potential to significantly increase cancer detection yield of breast MRI and thus make breast MRI a more cost-effective imaging modality in breast cancer screening.

Citation Format: Zheng B, Hollingsworth AB, Tan MY, Stough RG, Liu H. Improving efficacy of applying breast MRI to detect mammography-occult breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-02-06.

Atom probe tomography study of the nanoscale heterostructure around an Al20Mn3Cu2 dispersoid in aluminum alloy 2024

Atom probe tomography (APT) has been used to investigate the surface and sub-surface microstructures of aluminum alloy 2024 (AA2024) in the T3 condition (solution heat treated, cold worked, and naturally aged to a substantially stable condition). This study revealed surface Cu enrichment on the alloy matrix, local chemical structure around a dispersoid Al20Mn3Cu2 particle including a Cu-rich particle and S-phase particle on its external surface. Moreover, there was a significant level of hydrogen within the dispersoid, indicating that it is a hydrogen sink. These observations of the nanoscale structure around the dispersoid particle have considerable implications for understanding both corrosion and hydrogen embrittlement in high-strength aluminum alloys.

Blue dye is sufficient for sentinel lymph node biopsy in breast cancer

BACKGROUND

Most previous studies have reported superior results when blue dye and radiocolloids were used together for sentinel lymph node (SLN) biopsy in early breast cancer. Blue dye was reported to perform poorly when used alone, although more recent studies have found otherwise. This study reviewed the authors' practice of performing SLN biopsy with blue dye alone.

METHODS

This was a retrospective review of patients who underwent SLN biopsy using blue dye alone from 2001 to 2005, when SLN biopsy was performed selectively and always followed by axillary lymph node dissection (ALND), and from 2006 to 2010, when SLN biopsy was offered to all suitable patients and ALND done only when the SLN was not identified or positive for metastasis.

RESULTS

Between 2001 and 2005, 170 patients underwent SLN biopsy with blue dye alone. The overall SLN non-identification rate was 8·4 per cent. The overall false-negative rate was 34 per cent, but decreased with each subsequent year to 13 per cent in 2005. From 2006 to 2010, 610 patients underwent SLN biopsy with blue dye alone. The SLN was not identified in 12 patients (2·0 per cent) and no significant contributing factor was identified. A median of 2 (range 1-11) SLNs were identified. A non-SLN was found to be positive for metastasis in two patients with negative SLNs. Axillary nodal recurrence developed in one patient; none developed internal mammary nodal recurrence. Anaphylaxis occurred in one patient.

CONCLUSION

Blue dye performed well as a single modality for SLN biopsy. Non-identification, axillary nodal recurrence and serious allergic reactions were uncommon.

A brief structured education programme enhances self-care practices and improves glycaemic control in Malaysians with poorly controlled diabetes

We assessed the effectiveness of a brief structured diabetes education programme based on the concept of self-efficacy on self-care and glycaemic control using single-blind study design. One hundred and sixty-four participants with poorly controlled diabetes from two settings were randomized using computer-generated list into control (n = 82) and intervention (n = 82) groups, of which 151 completed the study. Monthly interventions over 12 weeks addressed the self-care practices of diet, physical activity, medication adherence and self-monitoring of blood glucose (SMBG). These self-care practices were assessed at Weeks 0 and 12 using pre- and post-questionnaires in both groups together with glycated haemoglobin A1c (HbA1c) and diabetes knowledge. In the intention-to-treat analysis (n = 164), the intervention group improved their SMBG (P = <0.001), physical activity (P = 0.001), HbA1c (P = 0.03), diabetes knowledge (P = <0.001) and medication adherence. At Week 12, HbA1c difference adjusted for SMBG frequency, medication adherence and weight change remained significant (P = 0.03) compared with control group. For within group comparisons, diabetes knowledge (P = <0.001), HbA1c level (P = <0.001), SMBG (P = <0.001) and medication adherence (P = 0.008) improved from baseline in the intervention group. In the control group, only diabetes knowledge improved (P = <0.001). These findings can contribute to the development of self-management diabetes education in Malaysia.

Phenol-oxidizing peroxidases contribute to the protection of plants from ultraviolet radiation stress

We have studied the mechanism of UV protection in two duckweed species (Lemnaceae) by exploiting the UV sensitivity of photosystem II as an in situ sensor for radiation stress. A UV-tolerant Spirodela punctata G.F.W. Meyer ecotype had significantly higher indole-3-acetic acid (IAA) levels than a UV-sensitive ecotype. Parallel work on Lemna gibba mutants suggested that UV tolerance is linked to IAA degradation rather than to levels of free or conjugated IAA. This linkage is consistent with a role for class III phenolic peroxidases, which have been implicated both in the degradation of IAA and the cross-linking of various UV-absorbing phenolics. Biochemical analysis revealed increased activity of a specific peroxidase isozyme in both UV-tolerant duckweed lines. The hypothesis that peroxidases play a role in UV protection was tested in a direct manner using genetically modified tobacco (Nicotiana sylvestris). It was found that increased activity of the anionic peroxidase correlated with increased tolerance to UV radiation as well as decreased levels of free auxin. We conclude that phenol-oxidizing peroxidases concurrently contribute to UV protection as well as the control of leaf and plant architecture.

Improvement of the in vitro dissolution of praziquantel by complexation with alpha-, beta- and gamma-cyclodextrins

Although praziquantel (PZQ) is the primary drug of choice in the treatment of schistosomiasis, its poor solubility has restricted its delivery via the oral route. In spite of its poor solubility, PZQ is well absorbed across the gastrointestinal tract, but large doses are required to achieve adequate concentrations at the target sites. Improving the solubility would enable the parenteral route to be used, thereby avoiding significant first pass metabolism. The aqueous solubility of PZQ was improved by forming inclusion complexes with alpha-, beta- and gamma-cyclodextrins (CDs). These complexes were assessed and confirmed by solubility analysis, Fourier transform infrared analysis, elemental analysis, differential scanning calorimetry and mass spectrometry. Dissolution of PZQ from the alpha-, beta- and gamma-CD complexes was 2.6-, 5- and 8-fold greater, respectively, than that of the pure drug. However, only the beta-complex had a stability constant in the optimum range for pharmaceutical use, suggesting that the preferred complex for further development would be a water-soluble beta-CD derivative.

The Mitchell distal metatarsal osteotomy for hallux valgus--the Singapore General Hospital experience

BACKGROUND

Fifty-five Mitchell distal metatarsal osteotomies for hallux valgus performed over a period of four years have been retrospectively reviewed. The 38 patients were followed for an average of 30 months (range 12 to 60 months).

RESULTS

The preoperative hallux valgus angle averaged 30.9 degrees +/- 8.2 degrees SD (range 18 degrees to 60 degrees) and the postoperative angle averaged 12.2 degrees +/- 4.6 degrees (range 5 degrees to 20 degrees).

CONCLUSION

Ninety-two percent of the patients were satisfied with the result of the procedure. They stated that, given the identical situation, they would undergo the operation again.

Chevron osteotomy for hallux valgus--SGH experience

Thirty-one chevron osteotomies for hallux valgus performed over a period of four years were reviewed. Their follow-up period ranged from one to five years. All the patients had pain over the bunion prior to operation. After operation, there was marked decrease of pain over the first matatarsophalangeal joint. The preoperative hallux valgus angle average 27 degrees and the postoperative angle averaged 12 degrees. The preoperative intermetatarsal angle averaged 13 degrees and the postoperative angle, 8 degrees. Ninety-one per cent of the patients were satisfied with the result of the procedure.

Anterior cruciate ligament reconstruction using patellar tendon autografts--a review of results

AIM

The aim of this retrospective study was to review the results of anterior cruciate ligament reconstruction using patellar tendon autografts.

METHODS

Forty-one knees were available for evaluation at a minimum of 24 months follow-up. Objective, subjective, functional and KT-1000 arthrometric tests were performed.

RESULTS

92.7% had a negative or trace pivot shift at follow-up. None of the patients had rupture of the autografts at review. The mean post-operative single-legged hop was 81%. The KT-1000 arthrometric evaluation post-operatively revealed a mean maximum manual difference of 0.5 mm; 90.2% of these patients had a maximum manual difference of less than 4 mm. Five patients (12.2%) had a "tighter" reconstructed knee (a negative mean maximum manual difference). More than 70% of the patients in this series had good to excellent results on functional, subjective and objective evaluation scores.

CONCLUSION

Excellent motion recovery, reliable stabilisation rates, good arthrometric results and encouraging post-operative functional, subjective and objective evaluation scores can be expected in patients undergoing anterior cruciate ligament reconstruction with patellar tendon autografts.

[Pharmacognostical identification and investigation of commercial product of traditional Chinese drug jiuyanduhuo]

Through investigation on original plants and commercial products of the traditional Chinese drug Jiuyanduhuo, the authors have ascertained its botanical origin and present medicinal usage, and found out that Aralia cordata is the main species of Jiuyanduhuo, and A. fargesii is another species that has come into use due to short supply of the main species, and A. henyri is used only in Sichuan and Hubei Provinces. Principal identification features of the original plants and crude drugs with 2 keys have been given, and TLC identification for 3 kinds of Jiuyanduhuo have also been carried out.

De Quervain's tenosynovitis and ganglion over first dorsal extensor retinacular compartment

Between 1988 to 1991, 80 cases of de Quervain's disease were managed at the Department of Orthopaedic Surgery, Singapore General Hospital. Six of them had an associated ganglion over the first dorsal retinacular compartment. Five out of 6 cases had intracompartment injections of hydrocortisone and lignocaine but the treatment was not effective in relieving the pain of de Quervain's tenosynovitis. All 6 cases had excision of the ganglion and decompression of the first extensor compartment. All the lumps were found arising from the dorsal aspect of the retinaculum and no intracompartment extension of the ganglion was found.

Studies on Crown Ether Complexes. XXXI. Synthesis, Properties and Structure of the Complexes of Lighter Lanthanide Nitrates With (Z)-2,3-Diphenyl-1,4,7,10,13-pentaoxacyclopentadec-2-ene (Stilbeno-15-crown-5)

Complexes of the lighter lanthanide nitrates with stilbeno-15-crown-5 (L) have been prepared in ethyl acetate. These new complexes with the general formula Ln (NO3)3.L.H2O ( Ln = La, Ce , Pr, Nd ) have been characterized by means of elemental analyses, i.r . spectra, 1H n.m.r. spectra and conductivity measurements. The crystal structure of La(NO3)3.L has been determined by X-ray methods, and refined to a residual R 0.0513 for 4937 independent reflections with I ≥ 1.5σ(I). It crystallizes in the monoclinic space group P21/a with a 16.090(5), b 15.654(8), c 22.687(2) Ǻ, β 93.96(4)°, V 5700(4)Ǻ3, and Z 8. There are two independent La(NO3)3.L monomers in one asymmetric unit; in each the coordination number is 11.