Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Universal vs selective ultrasonography to screen for large-for-gestational-age infants and associated morbidity

OBJECTIVES

To compare the diagnostic effectiveness of selective vs universal ultrasonography as a screening test for large-for-gestational-age (LGA) infants, and to determine whether previously described ultrasound markers of excessive fetal growth could identify suspected LGA fetuses that are at increased risk of adverse neonatal outcome.

METHODS

Data from the Pregnancy Outcome Prediction study, a prospective cohort study of nulliparous women with a viable singleton pregnancy at the time of the dating ultrasound scan, were analyzed. Women were selected for clinically indicated ultrasound assessment in the third trimester as per routine clinical care, and the results of these scans were reported ('selective ultrasonography'). In addition, all participants underwent research ultrasound scans, including estimated fetal weight (EFW) assessment, at around 36 weeks' gestation, in which both the women and their clinicians were blinded to the results ('universal ultrasonography'). Participants who attended the 36-week research scan and had a live birth at the Rosie Hospital were included in the study. Screen positive for LGA was defined as EFW > 90^th percentile at ≥ 34 weeks.

RESULTS

The current analysis included 3866 eligible women, of whom 1354 (35%) had a clinically indicated ultrasound scan at or after 34 weeks' gestation. A total of 177 (4.6%) infants had a birth weight > 90^th percentile. The sensitivity for detection of LGA infants was 27% for selective ultrasonography and 38% for universal ultrasonography. The specificity of both approaches was high (99% and 97%, respectively). Using universal ultrasonography, neonatal outcome differed (P for interaction) by abdominal circumference growth velocity (ACGV) for both any neonatal morbidity (P = 0.08) and severe adverse neonatal outcome (P = 0.03). LGA fetuses with increased ACGV had a relative risk of any neonatal morbidity of 2.0 (95% CI, 1.1-3.6; P = 0.04) and of severe adverse neonatal outcome of 6.5 (95% CI, 2.0-21.1; P = 0.01), whereas LGA fetuses with normal ACGV were not at increased risk.

CONCLUSIONS

Third-trimester screening of nulliparous women by universal ultrasound fetal biometry increases the detection rate of LGA infants and, combined with ACGV, identifies those at increased risk of adverse neonatal outcome. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Do we need transbronchial lung biopsy if we have bronchoalveolar lavage Xpert® MTB/RIF?

BACKGROUND

Studies evaluating the role of transbronchial lung biopsy (TBLB) in diagnosing pulmonary tuberculosis (PTB) date back decades and have shaped current practice. However, with the recent advent of bronchoalveolar lavage (BAL) Xpert® MTB/RIF, it is time to re-evaluate the role of TBLB.

OBJECTIVE

To assess the impact of BAL and TBLB with the addition of BAL Xpert on diagnostic PTB yields and time to treatment initiation in sputum-scarce or acid-fast bacilli (AFB) smear-negative PTB patients.

METHODS

We retrospectively reviewed all sputum-scarce or AFB smear-negative patients who underwent both BAL and TBLB for suspected PTB between March 2011 and October 2013. Xpert was performed on all BAL specimens.

RESULTS

Of 158 patients included in our analysis, 44 were culture-proven PTB. Ninety-four per cent of the patients had AFB smear-negative BAL samples. The sensitivity and specificity of Xpert in AFB smear-negative BAL samples were respectively 60% and 98%. The addition of BAL Xpert expedited the institution of PTB treatment while having diagnostic yields comparable to those of conventional BAL with TBLB.

CONCLUSIONS

The use of BAL Xpert may obviate the need for TBLB in increasing the diagnostic yield of PTB in sputum-scarce or AFB smear-negative patients.

Reduction of magnetic damping and isotropic coercivity and increase of saturation magnetization in Rh-incorporated CoIr system

Replacing Ir with Rh in a CoIr system possessing negative uniaxial magnetocrystalline anisotropy (K _u ) substantially reduces its magnetic damping and coercivity by more than half while retaining its high negative K _u . Moreover, a higher saturation magnetization (M _s ) and more isotropic coercivity are achieved. Such material development makes it particularly suitable for use as the soft underlayer (SUL) of magnetic recording media for reducing noise, and as the oscillation layer of a spin-torque oscillator (STO) for achieving higher oscillation frequency, larger AC magnetic field and lower driving current, which can be readily integrated with the current recording head for microwave-assisted magnetic recording. Finally, we recommend a composite free layer by coupling CoIr with a spin polarizer (Co or Co/Cu/Co) for the enhancement of the spin-polarization rate and, therefore, the improvement of STO efficiency. These could pave the way for CoIr-based materials to be implemented in devices requiring a negative K_u with low damping and high 'softness', such as oscillators.

Meta-analysis of gene-environment-wide association scans accounting for education level identifies additional loci for refractive error

Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia.

3D imaging of cement-based materials at submicron resolution by combining laser scanning confocal microscopy with serial sectioning

In this paper, we present a new method to reconstruct large volumes of nontransparent porous materials at submicron resolution. The proposed method combines fluorescence laser scanning confocal microscopy with serial sectioning to produce a series of overlapping confocal z-stacks, which are then aligned and stitched based on phase correlation. The method can be extended in the XY plane to further increase the overall image volume. Resolution of the reconstructed image volume does not degrade with increase in sample size. We have used the method to image cementitious materials, hardened cement paste and concrete and the results obtained show that the method is reliable. Possible applications of the method such as three-dimensional characterization of the pores and microcracks in hardened concrete, three-dimensional particle shape characterization of cementitious materials and three-dimensional characterization of other porous materials such as rocks and bioceramics are discussed.

Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM consortium

To identify genetic variants associated with refractive astigmatism in the general population, meta-analyses of genome-wide association studies were performed for: White Europeans aged at least 25 years (20 cohorts, N = 31,968); Asian subjects aged at least 25 years (7 cohorts, N = 9,295); White Europeans aged <25 years (4 cohorts, N = 5,640); and all independent individuals from the above three samples combined with a sample of Chinese subjects aged <25 years (N = 45,931). Participants were classified as cases with refractive astigmatism if the average cylinder power in their two eyes was at least 1.00 diopter and as controls otherwise. Genome-wide association analysis was carried out for each cohort separately using logistic regression. Meta-analysis was conducted using a fixed effects model. In the older European group the most strongly associated marker was downstream of the neurexin-1 (NRXN1) gene (rs1401327, P = 3.92E-8). No other region reached genome-wide significance, and association signals were lower for the younger European group and Asian group. In the meta-analysis of all cohorts, no marker reached genome-wide significance: The most strongly associated regions were, NRXN1 (rs1401327, P = 2.93E-07), TOX (rs7823467, P = 3.47E-07) and LINC00340 (rs12212674, P = 1.49E-06). For 34 markers identified in prior GWAS for spherical equivalent refractive error, the beta coefficients for genotype versus spherical equivalent, and genotype versus refractive astigmatism, were highly correlated (r = -0.59, P = 2.10E-04). This work revealed no consistent or strong genetic signals for refractive astigmatism; however, the TOX gene region previously identified in GWAS for spherical equivalent refractive error was the second most strongly associated region. Analysis of additional markers provided evidence supporting widespread genetic co-susceptibility for spherical and astigmatic refractive errors.

CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system

We have studied the CdSe/ZnS quantum dot (QD) size dependent carrier relaxation dynamics in hybrid organic/inorganic system for the first time. The QD size was from 5.0 to 2.0 nm. The optical narrow emission of quantum dots shift to higher energies as the size of dots gets smaller due to the 3-D confinement which splits the continuous band into a series of discrete quantum states and increases the band gap. The carrier relaxation time in QDs was found to increases as the pump power increased and reached saturation at approximately 326 microW excitation, probably due to the saturation of traps with the photoexcited charge carriers within individual nanoparticles. The relaxation rate was also increased with pump power, indicating that new relaxation processes e.g., Auger processes and faster carrier trapping were present. The slow decay component remained at the lowest power (51microW) excitation with no fast decay present. The decrease of CdSe/ZnS QD size increased the fast component relaxation rate probably due to a higher number of surface defects hence inducing faster trapping of carriers by shallow trap state.

Mapping the first electronic resonances of a Cu phthalocyanine STM tunnel junction

Using a low temperature, ultrahigh vacuum scanning tunneling microscope (STM), dI/dV differential conductance maps were recorded at the tunneling resonance energies for a single Cu phthalocyanine molecule adsorbed on an Au(111) surface. We demonstrated that, contrary to the common assumption, such maps are not representative of the molecular orbital spatial expansion, but rather result from their complex superposition captured by the STM tip apex with a superposition weight which generally does not correspond to the native weight used in the standard Slater determinant basis set. Changes in the molecule conformation on the Au(111) surface further obscure the identification between dI/dV conductance maps and the native molecular orbital electronic probability distribution in space.

Shifting atomic patterns: on the origin of the different atomic-scale patterns of graphite as observed using scanning tunnelling microscopy

We present an in-depth study of the myriad atomically resolved patterns observed on graphite using the scanning tunnelling microscope (STM) over the past three decades. Through the use of highly resolved atomic resolution images, we demonstrate how the interactions between the different graphene layers comprising graphite affect the local surface atomic charge density and its resulting symmetry orientation, with particular emphasis on interactions that are thermodynamically unstable. Moreover, the interlayer graphene coupling is controlled experimentally by varying the tip-surface interaction, leading to associated changes in the atomic patterns. The images are corroborated by first-principles calculations, further validating our claim that surface graphene displacement, coming both from lateral and vertical displacement of the top graphene layer, forms the basis of the rich variety of atomic patterns observed in STM experiments on graphite.

Channel selective tunnelling through a nanographene assembly

We report selective tunnelling through a nanographene intermolecular tunnel junction achieved via scanning tunnelling microscope tip functionalization with hexa-peri-hexabenzocoronene (HBC) molecules. This leads to an offset in the alignment between the energy levels of the tip and the molecular assembly, resulting in the imaging of a variety of distinct charge density patterns in the HBC assembly, not attainable using a bare metallic tip. Different tunnelling channels can be selected by the application of an electric field in the tunnelling junction, which changes the condition of the HBC on the tip. Density functional theory-based calculations relate the imaged HBC patterns to the calculated molecular orbitals at certain energy levels. These patterns bear a close resemblance to the π-orbital states of the HBC molecule calculated at the relevant energy levels, mainly below the Fermi energy of HBC. This correlation demonstrates the ability of an HBC functionalized tip as regards accessing an energy range that is restricted to the usual operating bias range around the Fermi energy with a normal metallic tip at room temperature. Apart from relating to molecular orbitals, some patterns could also be described in association with the Clar aromatic sextet formula. Our observations may help pave the way towards the possibility of controlling charge transport between organic interfaces.

Hydrothermally-grown ZnO nanowire tips for scanning tunnelling microscopy

The probe tip is pivotal in determining the resolution and nature of features observed in the Scanning Tunnelling Microscope (STM). We have augmented a conventional Pt/Ir metallic tip with a hydrothermally grown ZnO nanowire (NW). Atomic resolution imaging of graphite is attained. Current-voltage (IV) characteristics demonstrate an asymmetry stemming from the unintentional n-type doping of the ZnO NW, whereas the expected Schottky barrier at the ZnO-Pt/Ir interface is shown to have negligible effect. Moreover the photoconductivity of the system is investigated, paving the way towards a photodetector capable of atomic resolution.

Altering the ordering and disordering of a triangular nanographene at room temperature

Molecular self-organization has the potential to serve as an efficient and versatile tool for the spontaneous creation of low-dimensional nanostructures on surfaces. We demonstrate how the subtle balance between intermolecular interactions and molecule-surface interactions can be altered by modifying the environment or through manipulation by means of the tip in a scanning tunnelling microscope (STM) at room temperature. We show how this leads to the distinctive ordering and disordering of a triangular nanographene molecule, the trizigzag-hexa-peri-hexabenzocoronenes-phenyl-6 (trizigzagHBC-Ph6), on two different surfaces: graphite and Au(111). The assembly of submonolayer films on graphite reveals a sixfold packing symmetry under UHV conditions, whereas at the graphite-phenyloctane interface, they reorganize into a fourfold packing symmetry, mediated by the solvent molecules. On Au(111) under UHV conditions in the multilayer films we investigated, although disorder prevails with the molecules being randomly distributed, their packing behaviour can be altered by the scanning motion of the tip. The asymmetric diode-like current-voltage characteristics of the molecules are retained when deposited on both substrates. This paper highlights the importance of the surrounding medium and any external stimulus in influencing the molecular organization process, and offers a unique approach for controlling the assembly of molecules at a desired location on a substrate.

Osteo-odonto-keratoprosthesis for end-stage cornea blindness

We report the first case of Osteo-odonto-keratoprosthesis (OOKP) who successfully underwent surgery in Malaysia following a grade 4 (severe) chemical injury in both eyes in 2006. The patient's left eye was eviscerated and his right eye underwent penetrating keratoplasty. However, the corneal graft failed and became opaque. His right eye could only perceive light. The OOKP was offered to him hoping to recover some functional vision. He underwent a 2-stage surgery to implant the OOKP into his right eye. However, 2 months post-operation, he developed vitreous haemorrhage. A successful pars plana vitrectomy (PPV) was performed via the limited view through the lens. He attained a final visual acuity of 6/60 (N36). He was able to mobilize more independently, feed, dress himself and read large print.

The Adjunctive Use of Anti-vascular Endothelial Growth Factor Agents in the Management of Iris Neovascularisation in Malaysia

This retrospective study investigated the role of antivascular endothelial growth factor agents (VEGF), ranibizumab, bevacizumab and pegaptanib sodium in patients with iris neovascularisation (INV), in which 9 eyes received intraocular injections for various ischaemic ocular conditions. Ocular sequelae included recurrence of rubeosis (n=2) and hyphaema (n=2). Systemic complication included one case of cerebrovascular accident. INV regressed in all cases from day one. INV recurrence occurred in 2 cases. The mean intraocular pressure of the study eyes decreased from 25.3 mmHg to 18.3 mmHg at one month. Five eyes are medication free. Visual acuity improved in 5 eyes. Four eyes achieved a Snellen visual acuity of 6/24 or better. We conclude that the use of intraocular anti-VEGF agents are safe and effective for inducing the regression of INV. Patients with multiple systemic risk factors should be counseled on stroke risk.

Sonographic study of the decidua basalis in early pregnancy loss

OBJECTIVES

To describe the sonographic findings in the decidua basalis layer in spontaneous early pregnancy loss and to compare them with those in normal pregnancy.

METHODS

We reviewed 119 scans at 4-10 weeks' gestation from 110 patients who miscarried clinically at less than 13 weeks' gestation and 132 scans also at 4-10 weeks from 98 patients who had normal uncomplicated term pregnancies. The thickness and echogenicity of the decidua basalis layer were compared between pregnancies which suffered early loss and normal controls.

RESULTS

Relative thinning of the decidua basalis was observed in cases of early pregnancy loss from 5-6 weeks onwards when compared with normal pregnancies. In embryonic pregnancies that subsequently miscarried, the decidua basalis did not show the rising trend in thickness that was observed in normal pregnancies. Shortly before and after embryonic demise, the decidua appeared relatively more echogenic compared with that in normal pregnancy and the placenta showed areas of hypoechogenicity. Embryonic demise was followed by disorganization of the decidual layer, which became difficult to recognize. Pregnancy with an empty sac showed a more gradual trend in the thinning of the decidua basalis, but the uniformity and echogenicity of the layer appeared to be relatively better preserved with time.

CONCLUSION

The decidua basalis layer in pregnancies that are destined to miscarry in the first trimester differs sonographically from that in normal pregnancies. The sonographic differences are suggestive of a defective decidual-placental complex resulting from deficient trophoblastic invasion.

Comparative susceptibility of planktonic and 3-day-old Salmonella Typhimurium biofilms to disinfectants

AIMS

To compare the susceptibility of a 3-day-old biofilm and planktonic Salmonella to disinfectants at different exposure times. We hypothesize that Salmonella biofilms are more resilient to disinfectants compared to planktonic Salmonella.

METHODS AND RESULTS

The susceptibility of planktonic cells to disinfectants was tested by a modified version of the Council of Europe suspension test EN 1276. Salmonella biofilms were formed using the Calgary Biofilm Device. Results show that 3-day-old Salmonella biofilms are less susceptible to the disinfectants benzalkonium chloride, chlorhexidine gluconate, citric acid, quaternary ammonium compounds, sodium hypochlorite (SH) and ethanol, compared to planktonic Salmonella. Surprisingly, the results also demonstrate that low concentrations of SH were more effective against a 3-day-old biofilm compared to high concentrations of SH.

CONCLUSIONS

While all the disinfectants evaluated were able to reduce biofilm-associated cells at concentrations and contact times sufficient to eliminate planktonic cells, there were still sufficient viable cells remaining in the biofilm to cause further contamination and potential infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

Protocols for the use of chemical disinfectants need to include biofilm susceptibility testing. There is a requirement for an effective and standardized tool for determining the susceptibility of biofilms to disinfectants.

Step-by-step rotation of a molecule-gear mounted on an atomic-scale axis

Gears are microfabricated down to diameters of a few micrometres. Natural macromolecular motors, of tens of nanometres in diameter, also show gear effects. At a smaller scale, the random rotation of a single-molecule rotor encaged in a molecular stator has been observed, demonstrating that a single molecule can be rotated with the tip of a scanning tunnelling microscope (STM). A self-assembled rack-and-pinion molecular machine where the STM tip apex is the rotation axis of the pinion was also tested. Here, we present the mechanics of an intentionally constructed molecule-gear on a Au(111) surface, mounting and centring one hexa-t-butyl-pyrimidopentaphenylbenzene molecule on one atom axis. The combination of molecular design, molecular manipulation and surface atomic structure selection leads to the construction of a fundamental component of a planar single-molecule mechanical machine. The rotation of our molecule-gear is step-by-step and totally under control, demonstrating nine stable stations in both directions.

Sonographic study of the decidua basalis in the first trimester of pregnancy

OBJECTIVES

To describe the sonographic appearance of the decidua basalis and its changes in the first trimester of pregnancy.

METHODS

We reviewed images from 159 first-trimester ultrasound examinations in 105 women with uncomplicated pregnancies who later delivered at term. The appearance of the decidua basalis layer and the sonographic changes that it underwent, including in echogenicity and thickness, were analyzed with respect to gestational age.

RESULTS

A distinct decidual layer could be identified consistently at 5-6 weeks' gestation and its thickness peaked at 6-7 weeks. It was seen inconsistently at 8-9 weeks and was not identifiable by 10 weeks. Its appearance changed over time, from a uniformly echogenic layer at 5-6 weeks to a heterogeneous echogenic layer at 7 weeks, corresponding to the histological evidence of trophoblast penetration. The layer then became less echogenic with time until it became unidentifiable.

CONCLUSIONS

There is a window of opportunity in the first trimester for sonographic examination of the decidua. This may allow screening, at an early stage, for conditions that affect the decidua during pregnancy.

Examination of the secondary palate on stored 3D ultrasound volumes of the fetal face

OBJECTIVES

To examine the use of oblique planes from stored three-dimensional (3D) ultrasound volumes of the fetal face for viewing the secondary palate at various gestational ages.

METHODS

3D ultrasound volumes of the fetal face acquired with surface rendering at 15-35 weeks' gestation in 31 fetuses with confirmed normal secondary palates were reviewed. The secondary palate was viewed in three oblique planes targeted at the uvula: the oblique axial, the oblique sagittal and the reverse face view. The detection and appearance of the secondary palate, including the soft palate, with these views at various gestational ages were compared.

RESULTS

The various surfaces of the secondary palate could be viewed in all 31 fetuses in the oblique axial and the reverse face views, and in all except two fetuses in the oblique sagittal view. Both of these were < 19 weeks' gestation, at which age the uvula could not be identified clearly in this plane.

CONCLUSIONS

The oblique axial, the oblique sagittal and the reverse face view targeted at the uvula allow visualization of the various aspects of the fetal secondary palate on 3D ultrasound in the second and third trimesters of pregnancy. The uvula could be used as a landmark for viewing the soft palate, but was not always easily identifiable before 19 weeks' gestation.

A case of amyoplasia in a monochorionic twin pregnancy: a sequela from twin-twin transfusion syndrome?

OBJECTIVE

To present and discuss the sonographic and clinical findings in one twin of a monochorionic pair affected by amyoplasia.

METHODS

On ultrasound examination at 21 weeks in a monochorionic twin pregnancy, twin I was smaller, hydropic, with multiple contractures consistent with amyoplasia and oligohydramnios. Twin II was anatomically normal with polyhydramnios.

RESULTS

The twins were delivered at 28 weeks' gestation. The clinical findings were consistent with twin-twin transfusion syndrome (TTTS).

CONCLUSION

It is postulated that TTTS may be a causative factor in the excessive incidence of amyoplasia in monozygotic twin pregnancy.

Prevalence of metabolic syndrome in Chinese renal transplant recipients

OBJECTIVE

To investigate the prevalence of metabolic syndrome in Chinese renal transplant recipients, using two different sets of diagnostic criteria.

DESIGN

Cross-sectional study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

All Chinese patients who received solitary living-related or cadaveric kidney transplantation from 1 July 1997 to 31 December 2005 in our hospital with follow-up of more than 6 months were recruited. The diagnosis of metabolic syndrome was made according to the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) criteria and the International Diabetes Federation criteria.

RESULTS

Using the modified (Asian) NCEP-ATPIII criteria, a total of 39 (32%) of 121 patients had metabolic syndrome, which included 20/69 (29%) of the males and 19/52 (37%) of the females. Using the International Diabetes Federation criteria, metabolic syndrome was diagnosed in 26% of the patients, 22% in males and 31% in females. In our patients, the most common component of metabolic syndrome was hypertension and the least common was low high-density-lipoprotein-cholesterol level. Low high-density-lipoprotein-cholesterol levels were significantly more common in female patients.

CONCLUSION

This study shows that there is a high prevalence of metabolic syndrome in our Chinese renal transplant recipients.

A report of the Malaysian dialysis registry of the National Renal Registry, Malaysia

The Malaysian National Renal Registry was set up in 1992 to collect data for patients on renal replacement therapy (RRT). We present here the report of the Malaysian dialysis registry. The objectives of this papar are: (1) To examine the overall provision of dialysis treatment in Malaysia and its trend from 1980 to 2006. (2) To assess the treatment rate according to the states in the country. (3) To describe the method, location and funding of dialysis. (4) To characterise the patients accepted for dialysis treatment. (5) To analyze the outcomes of the dialysis treatment. Data on patients receiving dialysis treatment were collected at initiation of dialysis, at the time of any significant outcome, as well as yearly. The number of dialysis patients increased from 59 in 1980 to almost 15,000 in 2006. The dialysis acceptance rate increased from 3 per million population in 1980 to 116 per million population in 2006, and the prevalence rate from 4 to 550 per million population over the same period. The economically advantaged states of Malaysia had much higher dialysis treatment rates compared to the less economically advanced states. Eighty to 90% of new dialysis patients were accepted into centre haemodialysis (HD), and the rest into the chronic ambulatory peritoneal dialysis (CAPD) programme. The government provided about half of the funding for dialysis treatment. Patients older than 55 years accounted for the largest proportion of new patients on dialysis since the 1990s. Diabetes mellitus has been the main cause of ESRD and accounted for more than 50% of new ESRD since 2002. Annual death rate averaged about 10% on HD and 15% on CAPD. The unadjusted 5-year patient survival on both HD and CAPD was about 80%. Fifty percent of dialysis patients reported very good median QoL index score. About 70% of dialysis patients were about to work full or part time. There has been a very rapid growth of dialysis provision in Malaysia particularly in the older age groups. ESRD caused by diabetes mellitus, despite being a preventable and treatable cause of ESRD--has increased and accounted for more than 50% of incident dialysis patients. Death and survival rates on dialysis are comparable to those from other countries.

Antenatal diagnosis of anophthalmia by three-dimensional ultrasound: a novel application of the reverse face view

The prenatal diagnosis of anophthalmia can be made on the demonstration of absent eye globe and lens on the affected side(s) on two-dimensional ultrasound examination, but when the fetal head position is unfavorable three-dimensional (3D) ultrasound may reveal additional diagnostic sonographic features, including sunken eyelids and small or hypoplastic orbit on the affected side(s). We present two cases of isolated anophthalmia diagnosed on prenatal ultrasound examination in which 3D ultrasound provided additional diagnostic information. The reverse face view provides valuable information about the orbits and the eyeballs for prenatal diagnosis and assessment of anophthalmia.

Association between RANTES functional polymorphisms and tuberculosis in Hong Kong Chinese

Chemokines play a major role in leukocyte recruitment during the formation of tuberculous granulomas. We studied the association between genetic polymorphisms of three chemokines, monocyte chemoattractant protein-1 (MCP-1), RANTES (regulated on activation, normal T cell expressed and secreted) and macrophage inflammatory protein-1alpha (MIP-1alpha), and tuberculosis (TB). The distribution of five functionally significant single-nucleotide polymorphisms (SNPs), MCP-1 -2518A/G, RANTES -403G/A, -28C/G and In1.1T/C as well as MIP-1alpha +459C/T was not found to be different between patients with TB and healthy control subjects of the Hong Kong Chinese population. However, differences in linkage disequilibrium (LD) of the SNPs of RANTES and in distribution of the haplotypes of RANTES between patients with TB and healthy controls (P<0.0001) were found. Two risk haplotypes of RANTES, A-C-T and G-C-C, at positions -403, -28 and In1.1, respectively, were identified. Furthermore, combining the genotypes of RANTES -403 and In1.1, two diplotypes GA/TT (P<0.001) and GG/TC (P<0.0001) showed strong association with TB. Our findings support the association between RANTES functional polymorphisms and TB.

The practice of episiotomy in public hospitals in Hong Kong

OBJECTIVE

To review the use of episiotomy during vaginal delivery in Hong Kong public hospitals.

DESIGN

Prospective observational survey.

SETTING

Public hospitals, Hong Kong.

PARTICIPANTS

Women who underwent normal vaginal delivery of a singleton foetus with cephalic presentation.

MAIN OUTCOME MEASURES

Number of women having an episiotomy, severe-degree (third- or fourth-degree) tear, other types of tear, blood loss at delivery, postpartum haemorrhage, need for blood transfusion, puerperal pyrexia, wound infection, gaping wound that required suture removal, and drainage or resuturing of a perineal wound.

RESULTS

Between 1 January and 31 March 2003, there were 6222 singleton spontaneous normal vaginal deliveries in the public hospitals of Hong Kong. Of the 6167 women in whom the status of the perineum was known, episiotomy was performed in 5274 (85.5%). Primiparous women were more likely to undergo episiotomy at delivery than multiparous women (97.9% vs 71.4%). Women with episiotomy had significantly less perineal tearing of any kind than those without. The occurrence of any type of perineal tear and severe-degree (third- or fourth-degree) tear was significantly lower in primiparous women who had an episiotomy than those without (P<0.05). Women with episiotomy had increased mean blood loss at delivery but other complications were not significantly increased.

CONCLUSIONS

In Hong Kong, episiotomy is routinely performed during normal vaginal delivery. It is associated with a significantly lower overall rate of perineal tearing. This study was observational, nonetheless the occurrence of other complications was likely to increase when episiotomy was performed. Firm evidence from several randomised controlled studies shows that routine episiotomy is unjustified and possibly harmful. Routine episiotomy should not be promoted in Hong Kong without further randomised controlled study.

Quality of life in cadaver and living-related renal transplant recipients in Kuala Lumpur hospital

OBJECTIVE

To examine the quality of life in cadaver (CAD) and living-related (LRRT) renal transplant recipients.

METHODS

A cross-sectional study was done on patients followed in renal transplant clinic from 1/4/03 to 1/7/03 using the SF-36 questionnaire. Inclusion criteria were age >16 years,minimum of 3 months' posttransplant, and informed consent. Exclusion criteria were current treatment for rejection or infection or any life-threatening conditions. Information on duration of transplant, duration of dialysis prior to transplant, number of co-morbidities, and sociodemodraphic data were collected.

RESULTS

Sixty-four among 110 patients (58.1%) completed the SF36 questionnaire. The LRRT recipients were younger, had a longer duration of transplant, and had spent significantly less time on dialysis prior to transplant compared to CAD transplant patients. Overall, the physical composite and the mental composite scores were not significantly different between the two transplant groups. Age was negatively associated with the physical composite score (Spearman's rho -0.251, P < .05) and bodily pain (Spearman's rho -0.266, P < .05). Duration of dialysis prior to transplant was negatively correlated with social functioning (Spearman's rho -0.28, P < .05) and mental health (Spearman's rho -0.39, P < .005). In multiple regression analysis, age was a significant predictor of the SF36 physical composite score (P < .05).

CONCLUSION

This study shows that the quality of life between LRRT and CAD recipients was not significantly different. Increased age was associated with poorer physical capacity.

Body composition by bioelectrical impedance analysis in renal transplant recipients

Bioelectrical impedance analysis was introduced more than a decade ago to measure body composition and nutritional status. There are presently limited data on the nutritional status and body composition measured with bioelectrical impedance analysis in renal transplant recipients, especially among the Asian population. The normal values for these data in renal transplant recipients remain unknown.

METHODS

All renal transplant recipients with stable graft function who attended the outpatient renal transplant clinic in June 2003 were recruited for this cross-sectional study. Demographic and clinical data were obtained from participating patients and their outpatient clinic notes. Body composition and bioelectrical impedance data were obtained using the Metron BioScan 916 v3 analyzer.

RESULTS

Out of a total of 168 renal transplant recipients, 110 participated in this study of body composition and bioelectrical impedance for comparison with data from a previous study of 419 normal healthy volunteer controls. When compared to the healthy Malaysians, renal transplant recipients showed similar body composition in terms of body mass index, body cell mass, muscle bulk, percentage of body fat, percentage of fat free mass, and percentage of total body water. However, renal transplant recipients have more extracellular water, a lower phase angle, and a lower reactant.

CONCLUSION

Malaysians who have undergone renal transplantation have similar body composition to the healthy Malaysians when measurements are obtained using bioelectrical impedance analysis.

Reconstruction of shoulder function using a reflected long head biceps: a moment arm study

A tendon transfer technique is proposed for the reconstruction of the paralyzed shoulders secondary to brachial plexus injury. This innovative technique does not require bone-to-bone or tendon to-bone fixation, and attempts to overcome other clinical limitations such as those due to insufficient length of donor muscle. The approach is referred to as the reflected long head biceps (RLHB) technique. The long head of biceps tendons is utilized as a bridging tendon graft. Two surgical alternatives, namely the through-deltoid (TD) pathway and the sub-deltoid (SD) pathway, were studied. The moment arms of the transferred tendons were assessed and reported. The TD technique yielded a larger moment than the SD technique. In the plane 30 degrees anterior to the scapular plane, the average moment arms were 3.8cm TD and 3.0cm SD at zero elevation. Such differences tended to further widen with increasing elevation. At 80 degrees elevation, the moment arms became 3.2cm TD and 1.2cm SD. The results supported the clinical feasibility of this RLHB tendon transfer approach.

Quantitative polymerase chain reaction for the rapid prenatal diagnosis of homozygous alpha-thalassaemia (Hb Barts hydrops fetalis)

A quantitative polymerase chain reaction (Q-PCR) method based on the TaqMan technology has been devised for the prenatal diagnosis of homozygous alpha*-thalassaemia (south-east Asian type deletion). Primers and TaqMan probes were designed to specifically amplify an alpha*-thal chromosomal fragment or a normal alpha-chromosomal fragment. Variations in input target DNA in individual sample wells were normalized by the simultaneous amplification of a beta-actin gene fragment and results expressed as a ratio to that of beta-actin. There was no overlap of the data between the homozygous alpha*-thal, alpha*-thal and normal subjects. Up to 5% maternal DNA (alpha*-thal) contamination did not affect the specificity of the result. In 31 prenatal diagnoses, the result using Q-PCR compared favourably with the gold standard of Southern hybridization of alpha-genes.

The effect of fetal gender on nuchal translucency at 10-14 weeks of gestation

Recent data have suggested that fetal nuchal translucency (NT) is affected by fetal gender. We investigated the size of this effect in 12 189 unselected pregnancies with known normal outcomes that had undergone NT measurements between 10 and 14 weeks of gestation. NT increased with gestation and was converted to multiples of the median (MoM) for the gestational day. The median NT MoM (95% CI) for female fetuses was 0.98 (0.97-0.99). This was significantly lower than that of the male fetuses (1.03; range 1.02-1.04) (p<0.0005; Wilcoxon rank-sum test). The gender difference was not observed at 10 weeks but was observed from 11 weeks onwards. There is no obvious explanation for the above findings.

Embryonic and fetal globins are expressed in adult erythroid progenitor cells and in erythroid cell cultures

The understanding of human hemoglobin ontogeny during development is of biological and clinical importance. Molecular and immunocytological techniques were used to study the expression of embryonic zeta (zeta), epsilon (epsilon), and fetal gamma (gamma) globin genes in newborn cord blood, peripheral blood from men, pregnant and non-pregnant women, and in vitro mononuclear cell cultures. We have shown that embryonic and fetal globin mRNA and peptides are expressed in cultured erythroid cells and in circulating blood cells from newborns, adult non-pregnant women and from men. The findings suggest that during erythroid cell differentiation in newborns and adults, there is a transient recapitulation of sequential globin chain expression as found during embryonic and fetal development. Furthermore, these findings underscore the need for caution in using embryonic and fetal globin chains as markers to identify erythroid cells of fetal origin in maternal circulation for prenatal diagnosis.

Stability of reconstructed paralyzed shoulders using a reflected long head biceps technique

A new tendon transfer technique is proposed for the reconstruction of the paralyzed shoulders secondary to Brachial Plexus Injury (BPI). In this tendon transfer, the long head of the biceps tendons is utilized as a bridging tendon graft. It is reflected at the exit of the bicipital groove, passed through the deltoid and directed to the trapezius. The technique is referred to here as the Reflected Long Head Bicepts (RLHB) technique. This study evaluated the effect of this tendon transfer on the anterior, posterior, and inferior stability of the reconstructed should using cadaveric specimens. It was shown that loading of the RLHB contributed significantly to anterior stability of the reconstructed shoulder for 90 deg elevation in the scapula plane. The mean displacement was reduced by 56 percent with RLHB loaded (p<0.01), by 56 percent with the rotator cuff loaded (p <0.005), and by 67 percent with both the RLHB and the rotator cuff loaded (p<0.004). For the post-operation conditions, variation of the directions of RLHB had no significant effect on joint displacement in response to anterior loading. The RLHB tendon also contributed to the posterior and inferior stability for the low and middle elevations in the plane of scapula. Two variations of the RLHB tendon transfer procedures, namely the "Sub-Deltoid" and the "Through-Deltoid" techniques, were introduced and studied. These two techniques did not seem to have significantly different effects on the displacement of the humeral head in response to both posterior and inferior loading. The results of this study seemed to support the clinical feasibility of this tendon transfer approach as far as the biomedical stability of the reconstruction is concerned.

Conducting research on the Medicare market: the need for better data and methods

OBJECTIVE

To highlight data limitations, the need to improve data collection, the need to develop better analytic methods, and the need to use alternative data sources to conduct research related to the Medicare program. Objectives were achieved by reviewing existing studies on risk selection in Medicare HMOs, examining their data limitations, and introducing a new approach that circumvents many of these shortcomings.

DATA SOURCES

Data for years 1995-97 for five states (Arizona, Florida, Massachusetts, New York, and Pennsylvania) from the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SIDs), maintained by the Agency for Healthcare Research and Quality; and the Health Care Financing Administration's Medicare Managed Care Market Penetration Data Files and Medicare Provider Analysis and Review Files.

STUDY DESIGN

Analysis of hospital utilization rates for Medicare beneficiaries in the traditional fee-for-service (FFS) Medicare and Medicare HMO sectors and examination of the relationship between these rates and the Medicare HMO penetration rates.

PRINCIPAL FINDINGS

Medicare HMOs have lower hospital utilization rates than their FFS counterparts, differences in utilization rates vary across states, and HMO penetration rates are inversely related to our rough measure of favorable selection.

CONCLUSIONS

Substantial growth in Medicare HMO enrollment and the implementation of a new risk-adjusted payment system have led to an increasing need for research on the Medicare program. Improved data collection, better methods, new creative approaches, and alternative data sources are needed to address these issues in a timely and suitable manner.

Selection bias in HMOs: a review of the evidence

Early reviews found that health maintenance organizations (HMOs) attracted healthier beneficiaries in the Medicare program and healthier employees in the market for employer-based insurance. This review finds that HMOs still attract healthier Medicare beneficiaries, that HMOs no longer attract healthier employees, and that HMOs attract healthier Medicaid recipients. This review also found conflicting evidence about whether Medicare HMOs are overpaid, no evidence that HMOs are overpaid in the market for employer-based insurance, and evidence that concerns about overpaying Medicaid HMOs have diminished because many states are adopting mandatory programs.

The marginal benefits of invasive treatments for acute myocardial infarction: does insurance coverage matter?

This paper applies instrumental variable (IV) techniques and estimates the average benefits of invasive surgical treatments for marginal acute myocardial infarction (AMI) patients by insurance coverage. The study uses data from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project (HCUP), State Inpatient Databases for the state of Washington, for years 1988-1993. We observed differences in average benefits for marginal patients across insurance subpopulations that cannot be explained by differences in measured clinical circumstances. Our empirical results show that the insurance subpopulations with the greatest estimated marginal benefits are those with the lowest expected payment generosity to providers. Because of the relatively weak explanatory power of our instruments for three insurance subpopulations, and because many of the parameter estimates across the insurance subpopulations are not statistically different from each other, policy recommendations should be approached cautiously. However, our application of IV techniques to AMI patients demonstrates the usefulness of this approach to estimate treatment effects across patient populations (e.g., across types of insurance coverage) for medical conditions of interest to policymakers. These estimates may help determine whether treatments are overutilized or underutilized.

Acceptability of serum screening as an alternative to cytogenetic diagnosis of down syndrome among women 35 years or older in Hong Kong

The addition of second trimester serum markers to maternal age increases the efficacy of screening for Down syndrome by maternal age alone. Among women aged 35 years or older, serum screening makes a large proportion of amniocentesis unnecessary. However, there are ethical and medicolegal concerns about serum screening in 'old' women, largely because some of the pregnancies affected by Down syndrome and other chromosomal abnormalities may not be detected. We investigated the acceptability of serum screening in women aged 35 years or older when it was offered as an alternative to prenatal cytogenetic diagnosis after detailed counselling. Women referred for prenatal diagnosis of Down syndrome because of advanced maternal age were given the options of cytogenetic diagnosis by chorionic villus sampling (CVS) or amniocentesis. As an alternative, they could choose to undergo second trimester serum human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP) screening first before deciding on whether to undergo amniocentesis. Between January 1997 and October 1999, 3419 subjects were recruited. 1807 women (52. 9%) chose to undergo serum screening, 1516 women (44.3%) chose to have amniocentesis and 96 women chose to have CVS (2.8%). The proportion of women who chose serum screening rose steadily from 38. 8% in the year of 1997 to 63.4% in 1999. Significantly fewer Chinese women chose serum screening than non-Chinese. The decision as to whether to undergo an invasive diagnostic procedure or to be content with the relatively safer but less accurate screening test varies, being affected by the women's background and culture.

Cost effectiveness evaluation of the Ministry of Health Malaysia dialysis programme

We determine the cost effectiveness of centre and home haemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and intermittent peritoneal dialysis (IPD) treatment in the Ministry of Health (MOH) programme. The viewpoint taken for this evaluation is that of MOH. Cost categories identified were capital cost, dialysis operational cost, medical cost and general hospital cost. Cost estimates were mostly based on actual resource utilisation. Life years saved were estimated based on Dialysis Registry data on 2480 HD and 732 CAPD patients. Overall, the cost-effectiveness ratio (CER) of centre HD was RM21620/life year saved. Those of home HD, CAPD and IPD were RM23375, RM30469 and RM36016 respectively. Sensitivity analyses did not change the ranking of the CER. We conclude the MOH dialysis programme was cost-effective, and among the various dialysis modalities centre HD was the most cost-effective.

Outcome assessment of the Ministry of Health Malaysia dialysis programme

We describe the outcomes on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) provided by the Ministry of Health (MOH). The assessment was based on data from the Malaysian Dialysis Registry on 2480 HD and 732 CAPD patients who commenced dialysis between 1980 and 1996. Young patients (age < 40) have remarkable long term survival (life expectancies of 16 years on HD, 18 years on CAPD). Adjusting for background mortality, relative survival of older patients was as good as younger ones. Diabetics did poorly. 52% of HD and 26% of CAPD patients were employed in 1996. 71% of HD patients scored 10(normal) on QL index (a measure of quality of life) while 60% of CAPD patients have similar score. Differences in rehabilitation and QL index scores by age, gender and diabetes were also observed. Outcomes of dialysis in the MOH programme are reassuring.