Robust methodology for fractal analysis of the retinal vasculature

We have developed a robust method to perform retinal vascular fractal analysis from digital retina images. The technique preprocesses the green channel retina images with Gabor wavelet transforms to enhance the retinal images. Fourier Fractal dimension is computed on these preprocessed images and does not require any segmentation of the vessels. This novel technique requires human input only at a single step; the allocation of the optic disk center. We have tested this technique on 380 retina images from healthy individuals aged 50+ years, randomly selected from the Blue Mountains Eye Study population. To assess its reliability in assessing retinal vascular fractals from different allocation of optic center, we performed pair-wise Pearson correlation between the fractal dimension estimates with 100 simulated region of interest for each of the 380 images. There was Gaussian distribution variation in the optic center allocation in each simulation. The resulting mean correlation coefficient (standard deviation) was 0.93 (0.005). The repeatability of this method was found to be better than the earlier box-counting method. Using this method to assess retinal vascular fractals, we have also confirmed a reduction in the retinal vasculature complexity with aging, consistent with observations from other human organ systems.

Over-expression of protein kinase C isoforms (α, δ, θ and ζ) in squamous cervical cancer

Protein kinase C was found to be significantly over-expressed in cancer samples compared to adjacent normal cervical tissues by proteomics in our previous study. The aim of this study was to examine protein kinase C expression and to analyze the expression patterns of protein kinase C isoforms in squamous cervical cancer at the protein levels and their associations with clinical and pathologic factors of squamous cervical cancer. First, Western blotting was used to examine protein kinase C expression in the specimens of tumors and matched adjacent normal tissues which were collected from 12 patients with squamous cervical cancer. Protein kinase C isoforms (α, δ, θ and ζ) expression were then detected by immunohistochemistry in other 43 cases of squamous cervical cancer tissues, 32 cases of corresponding adjacent normal cervical squamous epithelial tissue and 31 cases of cervical intraepithelial neoplasia. Western blot analysis revealed that protein kinase C expression was positive in squamous cervical cancer while it was not expressed in normal cervical tissues. On the other hand, immunohistochemical analysis suggested that, protein kinase C isoforms (α, δ, θ and ζ) expression was significantly higher in squamous cervical cancer compared to cervical intraepithelial neoplasia, as well as in cervical intraepithelial neoplasia compared with normal tissues, respectively.High levels of protein kinase C α expression were associated with cellular differentiation(P<0.05). Protein kinase C δ was significantly associated with tumor stage (P<0.05) and protein kinase C ζ was associated with lymphatic metastasis (P < 0.05). These findings indicate that protein kinase C isoforms expression in cervical lesions was associated with carcinogenesis and might play important roles throughout the process of cervical cancer development.

Study of scattering from a sphere with an eccentrically located spherical inclusion by generalized Lorenz-Mie theory: internal and external field distribution

Based on the recent results in the generalized Lorenz-Mie theory, solutions for scattering problems of a sphere with an eccentrically located spherical inclusion illuminated by an arbitrary shaped electromagnetic beam in an arbitrary orientation are obtained. Particular attention is paid to the description and application of an arbitrary shaped beam in an arbitrary orientation to the scattering problem under study. The theoretical formalism is implemented in a homemade computer program written in FORTRAN. Numerical results concerning spatial distributions of both internal and external fields are displayed in different formats in order to properly display exemplifying results. More specifically, as an example, we consider the case of a focused fundamental Gaussian beam (TEM(00) mode) illuminating a glass sphere (having a real refractive index equal to 1.50) with an eccentrically located spherical water inclusion (having a real refractive index equal to 1.33). Displayed results are for various parameters of the incident electromagnetic beam (incident orientation, beam waist radius, location of the beam waist center) and of the scatterer system (location of the inclusion inside the host sphere and relative diameter of the inclusion to the host sphere).

Triennial Growth Symposium: important roles for L-glutamine in swine nutrition and production

L-Glutamine (Gln) has traditionally not been considered a nutrient needed in diets for livestock species or even mentioned in classic animal nutrition textbooks. This is due to previous technical difficulties in Gln analysis and the unsubstantiated assumption that animals can synthesize sufficient amounts of Gln to meet their needs. Consequently, the current (1998) version of NRC does not recommend dietary Gln requirements for swine. This lack of knowledge about Gln nutrition has contributed to suboptimal efficiency of global pig production. Because of recent advances in research, Gln is now known to be an abundant AA in physiological fluids and proteins and a key regulator of gene expression. Additionally, Gln can regulate cell signaling via the mammalian target of rapamycin pathway, adenosine monophosphate-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and nitric oxide. The exquisite integration of Gln-dependent regulatory networks has profound effects on cell proliferation, differentiation, migration, metabolism, homeostasis, survival, and function. As a result of translating basic research into practice, dietary supplementation with 1% Gln maintains gut health and prevents intestinal dysfunction in low-birth-weight or early-weaned piglets while increasing their growth performance and survival. In addition, supplementing 1% Gln to a corn- and soybean-meal-based diet between d 90 and 114 of gestation ameliorates fetal growth retardation in gilts and reduces preweaning mortality of piglets. Furthermore, dietary supplementation with 1% Gln enhances milk production by lactating sows. Thus, adequate amounts of dietary Gln, a major nutrient, are necessary to support the maximum growth, development, and production performance of swine.

High resolution imaging of actin filaments in living cells under physilogically relevant conditions using apertureless near-field microscopy

Living cells were used to demonstrate the potential biological applications of the apertureless SNOM when operating under fluid. An oral epithelial squamous cell carcinoma cell line (H357) was imaged under physiological-like conditions using apertureless SNOM following staining with FITC-Phalloidin which preferentially stains intracellular actin filaments of the cytoskeleton. Compared with simultaneously obtained AFM topographic image, the apertureless SNOM data provides greater detail on these cellular structures and the spatial resolution of the apertureless SNOM fluorescence image appears to be about 100 nm.

Retinal fractal dimension is increased in persons with diabetes but not impaired glucose metabolism: the Australian Diabetes, Obesity and Lifestyle (AusDiab) study

AIMS/HYPOTHESIS

The fractal dimension (D(f)) of the retinal vasculature is a global measure of its branching pattern complexity. We examined the relationship of retinal D(f) with diabetes.

METHODS

We conducted a cross-sectional study of 1,577 participants with diabetes and impaired glucose metabolism and normal controls from the population-based Australian Diabetes, Obesity and Lifestyle (AusDiab) study. Retinal D(f) was quantified from fundus photographs using a computer-based programme and diabetes status was determined by oral glucose tolerance test based on the WHO criteria.

RESULTS

After adjustment for age, sex and vascular risk factors, persons with higher retinal D(f) were more likely to have diabetes (OR 1.56; 95% CI 1.14-2.14, highest vs lowest fractal tertile). This relationship remained with further adjustment for retinal arteriolar calibre and presence of retinopathy (OR 1.64; 95% CI 1.19-2.27), and after excluding participants with retinopathy (OR 1.60; 95% CI 1.16-2.21). Retinal D (f) was not related to impaired glucose tolerance or impaired fasting glucose (OR 1.19; 95% CI 0.85-1.67).

CONCLUSIONS/INTERPRETATION

Individuals with diabetes, but not with impaired glucose metabolism, have greater retinal D(f), reflecting greater complexity of the retinal vasculature. Our findings suggest the presence of early microvascular changes in the retinal vasculature of persons with diabetes, even in the absence of overt retinopathy.

A first-principles approach to finite temperature elastic constants

A first-principles approach to calculating the elastic stiffness coefficients at finite temperatures was proposed. It is based on the assumption that the temperature dependence of elastic stiffness coefficients mainly results from volume change as a function of temperature; it combines the first-principles calculations of elastic constants at 0 K and the first-principles phonon theory of thermal expansion. Its applications to elastic constants of Al, Cu, Ni, Mo, Ta, NiAl, and Ni₃Al from 0 K up to their respective melting points show excellent agreement between the predicted values and existing experimental measurements.

A mixed-space approach to first-principles calculations of phonon frequencies for polar materials

We propose a mixed-space approach using the accurate force constants calculated by the direct approach in real space and the dipole-dipole interactions calculated by linear response theory in reciprocal space, making the accurate prediction of phonon frequencies for polar materials possible using the direct approach as well as linear response theory. As examples, by using the present approach, we predict the first-principles phonon properties of the polar materials α-Al(2)O(3), MgO, c-SiC, and h-BN, which are in excellent agreement with available experimental data.

Differential composition of proteomes in sow colostrum and milk from anterior and posterior mammary glands

Piglets obtaining milk from anterior and middle mammary glands (MG) grow faster than those suckling posterior MG, but the underlying mechanisms are not clear. The purpose of this study was to investigate the differential proteomes of colostrum and milk secreted by anterior and posterior MG. Six healthy primiparous sows with 7 pairs of MG were used; the first and the second pairs were defined as anterior MG and the sixth and seventh pairs as posterior MG. Colostrum and milk were collected at d 1 and 14 after parturition, respectively. Comparative proteomics analysis was performed to identify the differentially expressed proteins in colostrum and milk secreted by anterior and posterior MG. Results show that protein composition in colostrum and milk varied markedly with the anatomical location of MG. Immunoglobulins, lactadherin, and haptoglobin were upregulated (P < 0.05) in colostrum from anterior MG compared with posterior MG. Concentrations of immunoglobulins and lactoferrin in milk from anterior MG were greater (P < 0.05) than milk from posterior MG. Moreover, concentration of proteins from somatic cells was greater (P < 0.05) in milk from posterior MG compared with anterior MG. Most proteins, in which abundance was upregulated in colostrum and milk from anterior MG, contribute to passive immunity, intestinal development of suckling piglets and epithelial integrity, and the health of MG. Collectively, these results indicate that in comparison with posterior MG, anterior MG are more active in protein synthesis and produce more immunoglobulins and lactoferrin in colostrum and milk.

Food and nutrient consumption trends in older Australians: a 10-year cohort study

BACKGROUND/OBJECTIVES

Few longitudinal population-based cohort studies of older people have described dietary intakes over time. The objective of this study was to assess changes in the food and nutrient intake in a cohort of older Australians, using longitudinal data collected over 10 years.

SUBJECTS/METHODS

Population-based cohort of people aged 49 years and over at baseline (82% of those eligible) living in two postcode areas, west of Sydney. In 1992-1994, 3654 people were examined; 2334 were reexamined after 5 years and 1952 after 10 years (75% survivors at both examinations). A 145-item food frequency questionnaire was used to assess food and nutrient intake on each occasion, and 1166 participants provided usable dietary data at all three examinations.

RESULTS

Energy and sugar intake significantly increased among women over the 10-year period (P-value for trend <0.0001). Long-chain omega-3 fatty acid and fish intake significantly increased in both men and women (P-value for trend <0.0001). Folate intake significantly increased in both men and women (women: 325 dietary folate equivalents (DFE) vs 403 DFE; men: 346 DFE vs 425 DFE, P<0.0001). Wholemeal/grain bread consumption decreased in both men and women (P-value for trend <0.0001).

CONCLUSIONS

Many of the observed changes in diet over the 10-year period were consistent with current population dietary recommendations. Some changes, however, appear to have been due to poorer dietary choices. This information could be used to inform nutrition policy and programs targeted to older persons. These data highlight the need to identify barriers to better food choices.

Methotrexate treatment for ectopic pregnancy at the KK Women's and Children's Hospital, Singapore

INTRODUCTION

Ectopic pregnancy is an acute emergency in the first trimester where surgery is the mainstay of treatment. With the advent of improved diagnostic techniques like high-resolution transvaginal ultrasonography and expedient serum human chorionic gonadotrophin (HCG) assay, ectopic pregnancy is now diagnosed early. At this stage, the conceptus is often small, causing minimal or no symptoms. Medical management may then present an appealing alternative to surgery. Methotrexate has been widely used to treat ectopic pregnancy. A methotrexate ectopic treatment protocol was introduced by the Minimally Invasive Surgery Centre at KK Women's and Children's Hospital, Singapore. We present the results of this treatment.

METHODS

A prospective review of 110 cases of medical management of ectopic pregnancy since the implementation of the treatment protocol was undertaken. Demographical data, clinical presentation, treatment progress and outcome were captured using a computer database. All patients were managed as outpatients, and a telephone call-out service was provided to ensure that treatment side effects were monitored and potential treatment failures were identified early.

RESULTS

From August 2003 to October 2006, 93 (84.5 percent) patients with ectopic pregnancy were successfully treated with intramuscular methotrexate. 16 patients eventually required surgery and only one patient defaulted on follow-up. There was no major side effect detected in this cohort. The minor side effects reported included mucositis (19.1 percent) and abdominal pain (28.2 percent).

CONCLUSION

Methotrexate treatment of ectopic pregnancy is safe. Our treatment protocol enabled us to achieve a reasonable treatment success rate of 84.5 percent.

The formation of carbon nanostructures by in situ TEM mechanical nanoscale fatigue and fracture of carbon thin films

A technique to quantify in real time the microstructural changes occurring during mechanical nanoscale fatigue of ultrathin surface coatings has been developed. Cyclic nanoscale loading, with amplitudes less than 100 nm, is achieved with a mechanical probe miniaturized to fit inside a transmission electron microscope (TEM). The TEM tribological probe can be used for nanofriction and nanofatigue testing, with 3D control of the loading direction and simultaneous TEM imaging of the nano-objects. It is demonstrated that fracture of 10-20 nm thick amorphous carbon films on sharp gold asperities, by a single nanoscale shear impact, results in the formation of <10 nm diameter amorphous carbon filaments. Failure of the same carbon films after cyclic nanofatigue, however, results in the formation of carbon nanostructures with a significant degree of graphitic ordering, including a carbon onion.

Relationship of Type 2 diabetes to the prevalence, incidence and progression of age-related hearing loss

AIMS

Type 2 diabetes and associated microvascular abnormalities are postulated to affect hearing. Our study reports on the relationship between Type 2 diabetes and the prevalence, 5-year incidence and progression of hearing impairment in a representative, older, Australian population.

METHODS

The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss conducted in a defined suburban area, west of Sydney. Hearing loss was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0 and 4.0 kHz > 25 decibels hearing level (dB HL) in the better ear (bilateral hearing loss). Type 2 diabetes was defined from reported physician-diagnosed diabetes or fasting blood glucose > or = 7.0 mmol/l.

RESULTS

Age-related hearing loss was present in 50.0% of diabetic participants (n = 210) compared with 38.2% of non-diabetic participants (n = 1648), odds ratio (OR) 1.55 [95% confidence interval (CI) 1.11-2.17], after adjusting for multiple risk factors. A relationship of diabetes duration with hearing loss was also demonstrated. After 5 years, incident hearing loss occurred in 18.7% of participants with, and 18.0% of those without diabetes, adjusted OR 1.01 (CI 0.54-1.91). Progression of existing hearing loss (> 5 dB HL), however, was significantly greater in participants with newly diagnosed diabetes (69.6%) than in those without diabetes (47.8%) over this period, adjusted OR 2.71 (CI 1.07-6.86).

CONCLUSIONS

Type 2 diabetes was associated with prevalent, but not incident hearing loss in this older population. Accelerated hearing loss progression over 5 years was more than doubled in persons newly diagnosed with diabetes. These data explore further reported links between Type 2 diabetes and age-related hearing loss.

Angiotensin-converting enzyme gene and retinal arteriolar narrowing: the Funagata Study

The purpose of this study is to determine whether the angiotensin-converting enzyme (ACE) gene polymorphism is associated with retinal arteriolar narrowing, a subclinical marker of chronic hypertension. The Funagata Study examined a population-based sample of Japanese aged 35+ years; 368 participants had both retinal vessel diameter measurements and ACE insertion/deletion (ACE I/D) polymorphism analyses performed. Assessment of retinal vessel diameter and retinal vessel wall signs followed the protocols used in the Blue Mountains Eye Study. ACE gene polymorphisms D/D, I/D and I/I were present in 34 (9.2%), 170 (46.2%) and 164 (44.5%) participants, respectively, distributed in Hardy-Weinberg equilibrium. After multivariable adjustment, retinal arteriolar diameter was significantly narrower in subjects with the D/D genotype compared to subjects with I/D and I/I genotypes (mean difference -6.49 microm, 95% confidence interval (CI): -12.86 microm, -0.11 microm). Our study suggests that the ACE I/D polymorphism may be associated with subclinical structural arteriolar changes related to chronic hypertension.

Blood pressure control and awareness among patients with diabetes and hypertension attending a tertiary ophthalmic clinic

AIMS

To assess the proportion of patients who had diabetes and hypertension with optimal blood pressure (BP) control and to describe patients' awareness of the importance of BP control.

METHODS

A cross-sectional survey of out-patients with diabetes who attended the Royal Victorian Eye and Ear Hospital (Melbourne, Australia) was conducted between October 2006 and February 2007. Of 245 patients invited, 220 (90%) participated. Optimal BP control was defined as BP < 130/80 mmHg recorded at the latest visit; proportions of patients with awareness of BP control were defined non-exclusively by: (i) ability to recall a previous BP record and rate the appropriateness of that BP level; (ii) ability to recall the recommended optimal BP control level by current diabetes management guidelines; (iii) knowledge that optimal BP control is important to diabetes management; and (iv) knowledge that optimal BP control is important to eye health.

RESULTS

Of the 220 patients, 176 had both diabetes and hypertension. Of these, 49 of 176 (28%) had BP controlled optimally, and 30 of 176 (17%) recalled and rated a previous recorded BP level appropriately. Fewer than one in four (22%) acknowledged the recommended optimum BP level of < 130/80 mmHg, fewer than one in two (48%) rated BP as important to diabetes management, and one in three (35%) rated BP control as important to eye health.

CONCLUSIONS

In this sample of patients with diabetes and hypertension, fewer than one-third achieved the BP level recommended by clinical guidelines, and fewer than half were aware of the importance of BP control.

Anti-angiogenic factors and pre-eclampsia in type 1 diabetic women

AIMS/HYPOTHESIS

Elevated anti-angiogenic factors such as soluble fms-like tyrosine kinase 1 (sFlt1), a soluble form of vascular endothelial growth factor receptor, and endoglin, a co-receptor for TGFbeta1, confer high risk of pre-eclampsia in healthy pregnant women. In this multicentre prospective study, we determined levels of these and related factors in pregnant women with type 1 diabetes, a condition associated with a fourfold increase in pre-eclampsia.

METHODS

Maternal serum sFlt1, endoglin, placental growth factor (PlGF) and pigment epithelial derived factor were measured in 151 type 1 diabetic and 24 healthy non-diabetic women at each trimester and at term.

RESULTS

Approximately 22% of the diabetic women developed pre-eclampsia, primarily after their third trimester visit. In women with pre-eclampsia (diabetic pre-eclampsia, n = 26) vs those without hypertensive complications (diabetic normotensive, n = 95), significant changes in angiogenic factors were observed, predominantly in the early third trimester and prior to clinical manifestation of pre-eclampsia. Serum sFlt1 levels were increased approximately twofold in type 1 diabetic pre-eclampsia vs type 1 diabetic normotensive women at the third trimester visit (p < 0.05) and the normal rise of PlGF during pregnancy was blunted (p < 0.05). Among type 1 diabetic women, third trimester sFlt1 and PlGF were inversely related (r(2) = 42%, p < 0.0001). Endoglin levels were increased significantly in the diabetic group as a whole vs the non-diabetic group (p < 0.0001).

CONCLUSIONS/INTERPRETATION

Higher sFlt1 levels, a blunted PlGF rise and an elevated sFlt1/PlGF ratio are predictive of pre-eclampsia in pregnant women with type 1 diabetes. Elevated endoglin levels in women with type 1 diabetes may confer a predisposition to pre-eclampsia and may contribute to the high incidence of pre-eclampsia in this patient group.

The effect of site-directed mutagenesis of the ambient amino acids of leucine-based sorting motifs on the localization of chicken invariant chain

Two Leu residues and their ambient amino acid residues are known to exist in the cytosolic tail of chicken invariant chain (Ii), and these play an important role as motifs in mediating the sorting endocytic pathway. We performed 20 mutations via site-directed mutagenesis by the PCR megaprimer method to study the effect of some ambient amino residues of both Leu on the localization of chicken Ii. These mutated fragments were ligated to the vector pEGFP-C1. The recombinant plasmids were transiently transfected into COS-7 cells with Lipofectamine 2000. Furthermore, the fluorescence of located fusion proteins (green fluorescent protein-Ii) was observed with a fluorescence microscope. Our results indicated that 2 Leu-based motifs are required for chicken Ii intracellular localization, and both motifs independently mediate this function of the Ii. The other amino acid residues surrounding both Leu also influence Ii-induced endosomal vacuolation. In addition, we found that Pro19, which is near the Val17-Leu18 motif, was a key residue for chicken Ii intracellular localization. Not only is it critical for endocytic targeting to each Leu, but its unique mutation can also result in altering the function of chicken Ii.

Association between self-rated health and incident severe hypertension among men: a population-based cohort study

INTRODUCTION

Self-rated health (SRH) is a consistent predictor of cardiovascular disease and mortality. However, the intermediate biological mechanisms behind this association are not clear. We examined the longitudinal relationship between SRH and incident severe hypertension.

METHODS

We studied a population-based cohort of 1,298 participants (mean age 62.5 years, range 49-84 years), at the baseline examination (1992-1994) residing in the Blue Mountains region, west of Sydney, Australia, and re-examined after five years (1997-1999). Main outcome-of-interest was incident severe hypertension (systolic blood pressure [BP] 160 mmHg or above, diastolic BP 100 mmHg or above, or a combination of self-reported hypertension diagnosis and use of antihypertensive medications) among baseline individuals without severe hypertension.

RESULTS

Among men, those with fair/poor SRH had significantly higher odds of incident severe hypertension, compared to individuals with excellent SRH. Multivariable odds-ratio (OR) (95 percent confidence intervals [CI]) comparing fair/poor SRH to excellent SRH was 1.93 (1.04-3.56) (p-trend was 0.03). This association was not observed in women comparing fair/poor SRH to excellent SRH: OR 0.96, 95 percent CI 0.57-1.62 (p-trend was 0.70). Subgroup analyses stratified by age, smoking, body mass index, diabetes mellitus and BP categories, supported this male gender-specific pattern of association.

CONCLUSION

This data suggests an association between poor SRH and incident hypertension among men, but not among women. These results suggest that at least part of the previously-reported association between poor SRH and mortality may be mediated by its relation to incident severe hypertension.

Stereoselectivity in metabolism of ifosfamide by CYP3A4 and CYP2B6

The aim was to identify the hepatic cytochromes P450 (CYPs) responsible for the enantioselective metabolism of ifosfamide (IFA). The 4-hydroxylation, N2- and N3-dechloroethylation of IFA enantiomers were monitored simultaneously in the same metabolic systems using GC/MS and pseudoracemate techniques. In human and rat liver microsomes, (R)-IFA was preferentially metabolized via 4-hydroxylation, whereas its antipode was biotransformed in favour of N-dechloroethylation. CYP3A4 was the major enzyme responsible for metabolism of IFA enantiomers in human liver. The study also revealed that CYP3A (human CYP3A4/5 and rat CYP3A1/2) and CYP2B (human CYP2B6 and rat CYP2B1/2) enantioselectively mediated the 4-hydroxylation, N2- and N3-dechloroethylation of IFA. CYP3A preferentially supported the formation of (R)-4-hydroxyIFA (HOIF), (R)-N2-dechloroethylIFA (N2D) and (R)-N3-dechloroethylIFA (N3D), whereas CYP2B preferentially mediated the generation of (S)-HOIF, (S)-N2D and (S)-N3D. The enantioselective metabolism of IFA by CYP3A4 and CYP2B1 was confirmed in cDNA transfected V79 cells.

Enantiomer–enantiomer interaction of ifosfamide in the rat

The objective of this study was to study the enantiomer-enantiomer interaction of ifosfamide (IFA) in a rat model. Following intravenous administration of individual IFA enantiomers or pseudo-racemates to male Sprague-Dawley rats, two enantiomers and their metabolites, 4-hydroxyIF (HOIF), N2-dechloroethylIF (N2D), N3-dechloroethylIF (N3D), and isophosphoramide (IPM), were quantified using gas chromatography/mass spectrometry (GC/MS) and isotope dilution techniques. In addition, the mutual inhibition in the metabolism between two stereoisomers was also investigated in vitro using rat liver microsomes. Pharmacokinetic parameters were similar between (R)-IFA and (S)-IFA when individual enantiomers were intravenously administered to rats separately. However, in the rats administered with the IFA racemate, half-life, mean residence time (MRT), and area under the concentration-time curve (AUC) values of (S)-IFA were significantly increased with total body clearance (CLT) being decreased. No significant difference in volumes of distribution (Vss), and renal clearance (CLr) and blood cell partition was observed between two enantiomers regardless of (R)-IFA and (S)-IFA being administered separately or in combination as a racemate. The results from the in vitro metabolism and inhibition experiment suggested that each IFA enantiomer inhibited the metabolism of its antipode in a competitive manner. It is concluded that the enantiomeric interaction of IFA mainly occurred in the process of metabolism with (S)-IFA being affected to a larger extent.

Retinopathy predicts coronary heart disease mortality

BACKGROUND

Retinopathy lesions are fairly common findings in clinic settings and may predict risk of coronary heart disease (CHD).

OBJECTIVE

To examine whether retinopathy independently predicts a risk of CHD-related mortality in people with and without diabetes.

METHODS

In an Australian population-based cohort of people with (n = 199) and without (n = 2768) diabetes (Blue Mountains Eye Study, total n = 2967), the presence and severity of retinopathy was assessed from retinal photographs. 12-Year cumulative CHD deaths were ascertained from Australian National Death Index records.

RESULTS

Over 12 years, 353 participants (11.9%) had incident CHD-related deaths. Retinopathy was present in 57/199 (28.6%) participants with, and in 268/2768 (9.7%) without, diabetes. The presence of retinopathy increased the CHD mortality rate per person-year by an amount (0.005) equivalent to the presence of diabetes itself (12-year CHD mortality rate per person-year of 0.010 in people with neither diabetes nor retinopathy, 0.015 in those with diabetes alone, 0.016 in those with retinopathy alone). After adjusting for cardiovascular risk factors, retinopathy remained an independent predictor of CHD death both in people with diabetes (hazard ratio (HR) = 2.21, 95% CI 1.20 to 4.05) and in those without diabetes (HR = 1.33, 95% CI 1.02 to 1.83). Moderate retinopathy was associated with adjusted HR = 6.68 (95% CI 2.24 to 20.0) in people with diabetes and adjusted HR = 2.29 (95% CI 1.10 to 4.76) in people without diabetes.

CONCLUSIONS

A finding of retinopathy in people with or without diabetes may signal increased CHD risk. The increased CHD mortality associated with retinopathy in people without diabetes was equivalent to the presence of diabetes itself.