Divergent mechanisms of cis 9, trans 11 ‐ and trans 10 , cis 12 ‐ conjugated linoleic acid affecting insulin resistance and inflammation in apolipoprotein E knockout mice: a proteomics approach

Conjugated linoleic acids (CLA) affect atherogenesis, but mechanisms are not well understood. We explored how two isomers of CLA, cis9, trans11-CLA and trans10, cis12-CLA, affected lipid and glucose metabolism, as well as hepatic protein expression, in apolipoprotein E knockout mice. After 12 wk of intervention, plasma triglyceride, NEFA, and glucose concentrations were significantly higher in the trans10, cis12-CLA group, whereas plasma triglyceride, NEFA, glucose, and insulin concentrations were significantly lower in the cis9, trans11-CLA group, compared with control mice consuming linoleic acid. Proteomics identified significant up- or down-regulation of 113 liver cytosolic proteins by either CLA isomer. Principal component analysis revealed that the treatment effect of cis9, trans11-CLA was mainly explained by the up-regulation of different posttranslational forms of heat shock protein 70 kD. In contrast, the treatment effect of trans10, cis12-CLA was mainly explained by up-regulation of key enzymes in the gluconeogenic, beta-oxidation, and ketogenesic pathways. Correlation analysis again emphasized the divergent effects of both CLA isomers on different pathways, but also revealed a linkage between insulin resistance and increased levels of hepatic serotransferrin. Thus, our systems biology approach provided novel insights into the mechanisms by which individual CLA isomers differentially affect pathways related to atherogenesis, such as insulin resistance and inflammation.

Stress-induced ATP release from and growth modulation of human lens and retinal pigment epithelial cells

ATP release has been shown to occur following stimulation in several cellular systems. This study was undertaken to determine if lens and retinal epithelial cells release ATP in response to physiological stresses and to elucidate a possible role for ATP. Analysis of human aqueous humour samples showed a mean ATP level of 37.8+/-7.7 nM. Hyper-osmotic stress induced a dose- and time-dependent release of ATP. Both cell types were found to proliferate in serum-free medium, and the addition of ATP and adenosine at concentrations as low as 0.1 nM inhibited growth. Gene profiling also demonstrated the presence of the ectonucleotidases CD39 and CD73 and the A1 adenosine receptor on both cell types.

Bacteraemia and antibiotic use in respiratory syncytial virus infections

AIMS

To examine the frequency of and risk factors for bacteraemia in children hospitalised with respiratory syncytial virus (RSV) infection; and to determine current use of antibiotics in hospitalised children with RSV infection.

METHODS

Retrospective study of all children, aged 0-14 years, admitted to a tertiary children's hospital with proven RSV infection over a four year period. Children with concurrent bacteraemia and RSV infection were identified, and risk factors examined for bacteraemia. The case notes of a randomly selected comparison sample of 100 of these RSV infected children were examined to assess antibiotic use and population incidence of risk factors for severe RSV infection.

RESULTS

A total of 1795 children had proven RSV infection, and blood cultures were sent on 861 (48%). Eleven (0.6%) of the 1795 RSV positive children had bacteraemia. RSV positive children had a significantly higher incidence of bacteraemia if they had nosocomial RSV infection (6.5%), cyanotic congenital heart disease (6.6%), or were admitted to the paediatric intensive care unit (2.9%). Forty five (45%) of the random comparison sample of RSV infected children received antibiotics.

CONCLUSIONS

Bacteraemia is rare in RSV infection. Children with RSV infection are more likely to be bacteraemic, however, if they have nosocomial RSV infection, cyanotic congenital heart disease, or require intensive care unit admission.

Characterisation of TGF-β2 signalling and function in a human lens cell line

There is increasing evidence implicating Transforming growth factor beta (TGF-beta) in pathological states of the lens. However, the underlying signalling mechanisms in human cells have not been fully examined. We have therefore investigated in a human lens cell line, FHL 124, the signalling characteristics of TGF-beta and Smad proteins. Moreover, we have tested the effectiveness of a fully human monoclonal anti-TGF-beta2 antibody, CAT-152, in suppressing TGF-beta2 induced changes in a number of conditions. FHL 124 cells were routinely cultured in Eagle's minimum essential medium (EMEM) supplemented with 10% FCS. Characterisation of the cell line was determined using Affymetrix gene microarrays and compared to native human lens epithelium. Cells were serum starved for 24 hr prior to exposure to TGF-beta2 in the presence and absence of CAT-152. Non-stimulated cells served as controls. Smad 4 localisation was observed by immunocytochemistry. To study Smad-dependent transcriptional activity, cells were transfected with SBE4-luc, an artificial smad-specific reporter, using Fugene-6. Transcriptional activity was determined by luciferase activity. Gene expression was assessed using reverse transcriptase-polymerase chain reaction (RT-PCR). Proliferation was determined by 3H-thymidine DNA incorporation. Growth and contraction were assessed using a scratch and patch assay. Affymettrix gene microarrays identified 99.5% homology between FHL 124 cells and the native lens epithelium with respect to expression pattern of the 22,270 genes on the chip. Moreover, FHL 124 cells expressed phenotypic markers, alphaA-crystallin and pax6 along with lens epithelial cell specific marker FoxE3. Immunocytochemical studies revealed the presence of Smad 4 which following TGF-beta2 exposure accumulated in the cell nucleus. Furthermore, Smad-dependent transcriptional activity was also stimulated. TGF-beta2 enhanced the expression of mRNA levels of alpha smooth muscle actin (alphaSMA) and connective tissue growth factor (CTGF). Exposure to TGF-beta2 resulted in a relatively small inhibition of 3H-thymidine incorporation of FHL 124 cells. However, a more marked contractile effect was also observed. In serum-supplemented medium, growth rates and TGF-beta induced contraction were enhanced. Treatment with 0.1-10 microg ml(-1) CAT-152 dose-dependently inhibited 10 ng ml(-1) TGF-beta2 induced effects in the presence and absence of serum. Exposure of FHL 124 cells to TGF-beta therefore induces Smad translocation, transcription, expression of transdifferentiation markers and induces marked contraction. Treatment with CAT-152 can effectively inhibit these responses. TGF-beta2 induced changes can also persist long after the period of exposure and when in the presence of serum TGF-beta induced contraction is enhanced. The work presented therefore demonstrates a platform technology to study TGF-beta2 signalling in human lens epithelial cells and provides evidence to show TGF-beta2 can be a potent factor in the development of posterior capsule opacification following cataract surgery.

Nasal fracture manipulation: a comparative study of general and local anaesthesia techniques

Nasal injuries are common conditions treated in either Otolaryngology or Plastic Surgical departments. Manipulation for deformity can be conducted in various ways. The aim of this study is to determine if the anaesthetic technique used for manipulation influences outcomes. Five hundred and fifty-five patients had either local anaesthetic (LA) or general anaesthetic (GA) nasal fracture manipulations in our departments over a 6-year period. Three hundred and twenty-four of these could be contacted and questioned as to subsequent surgical treatments received. Rhinoplasty, septorhinoplasty or septoplasty had been subsequently performed in 3.2% of the GA group and in 17.2% of the LA group (P < 0.0001). We recommend considering this result when treating nasal fractures in conjunction with other important issues of patient preference, financial costs, associated risks, morbidity and facilities available.

Marek's disease, candidiasis and megabacteriosis in a flock of chickens (Gallus gallus domesticus ) and Japanese quail (Coturnix japonka )

An outbreak of mortality in chickens and Japanese quail sharing the same airspace was investigated. Marek's disease was diagnosed in five of 11 chickens examined, and in 20 of 24 quail; crop candidiasis was found in four of the chickens and in five of the quail, and moderate to large numbers of organisms referred to as megabacteria were observed in eight of the chickens and 16 of the quail. The disease was so severe that almost all of the quail in the flock died or were culled during the following six months. In contrast, only approximately 5 per cent of the chickens died from Marek's disease.

Epithelial transdifferentiation and cataract in the human lens

Anterior subcapsular cataracts cause a serious loss of vision and are normally associated with ocular trauma, inflammation or clinical skin conditions. They appear to be accompanied by epithelial cell growth and transdifferentiation where unscheduled production of a number of proteins, including alpha smooth muscle actin (alpha-sma), occurs. Clinical studies have also revealed an up-regulation of the TGFbeta signalling pathway in such cataracts. The present study, using phase contrast and immunofluorescent techniques, was undertaken to investigate the extent of alpha-sma expression in traumatic cataracts, in capsulorhexis specimens obtained during cataract surgery and in aged human lenses from donor eyes. The donor lenses were also exposed to trauma or TGFbeta in culture to observe their relative contribution to alpha-sma production. Dense anterior subcapsular cataracts were relatively rare (<1%), but all showed a pronounced up-regulation of alpha-sma, which was located both in anterior cells of normal appearance and in nucleated fibroblastic cells lying beneath the anterior epithelium. Surprisingly, more than 50% of capsulorhexis specimens from mature cataracts showed expression of alpha-sma, although to a limited extent. Alpha-sma was not expressed in any of the clear donor lenses and culture for 8 days in EMEM did not induce expression. Interestingly, unlike their young animal counterparts, human lenses failed to show the presence of alpha-sma when exposed to 10 ng ml(-1) TGFbeta. However, after culture, lenses with pre-existing cortical opacities did express alpha-sma, as did clear lenses subjected to injury or trauma. It appears that the greater the stress, the greater is the expression of alpha-sma. Cataract, and especially cortical cataract, should therefore be seen as associated with stress-induced signalling pathways in the lens that lead to the transdifferentiation of the anterior epithelial cells.

Role of the non-neuronal cholinergic system in the eye: a review

Pharmacologically active preparations directed towards modulating muscarinic receptor activity in the eye have been used for over 2000 years when extracts from Atropa belladonna were first applied to enhance eye appearance through pupillary dilation. The first clinically active drugs targeting a specific eye disease were anticholinesterases (e.g. ecothiophate) applied as eye drops to treat glaucoma in the 1960's. However, cataract was soon detected as a relatively frequent side effect and such drugs are now only used to treat glaucoma as a last resort. As muscarinic agonists have been found to reduce intraocular pressure both by decreasing aqueous humour production (through Na,K-ATPase pump inhibition) and increasing outflow (by muscle contraction), it is likely that treatments will be developed that target specific muscarinic subtypes. Recently, it has been shown that the M1 receptor subtype predominates in the lens. It is therefore important that this subtype is not targeted in future ocular therapies so that the side-effect of cataract is avoided. Form-deprived myopia resulting from an increased axial length in the affected eye can be reduced by the application of atropine. This effect has been achieved both in a chick model system and in human clinical trials, and in the former system atropine has been shown to reduce the production of scleral extracellular proteins. Carbachol stimulates tear fluid production through the activation of muscarinic receptors. Interestingly, at least part of the stimulation occurs via epidermal growth factor (EGF) receptors and although the precise signalling mechanisms are not completely understood, it has been shown that calcium mobilisation plays a critical role in both muscarinic and EGF receptor activity. It should be noted that in the four examples described above, the cell types responsible for producing the physiological output are non-neuronal in origin. Therefore cholinergic receptor activation plays diverse roles in the eye and pharmacological intervention based on specific receptor sub-types has potential benefit in a number of ocular problems. However, potential side effects have also recently been identified.

Relationship between all-cause mortality and cumulative working life course psychosocial and physical exposures in the United States labor market from 1968 to 1992

OBJECTIVE

To examine the relationship between cumulative exposures to psychosocial and physical work conditions and mortality in a nationally representative sample.

METHODS

A working cohort was created using the U.S. Panel Study of Income Dynamics. Information on psychosocial and physical work conditions were imputed using the Job Characteristics Scoring System exposure matrix for the period 1968 through 1991 to construct working life courses. Deaths were ascertained from 1970 through 1992.

RESULTS

Working in low-control jobs for a working life was associated with a 43% increase in the chance of death (OR, 1.43, 1.13-1.81) assuming a 10-year time lag. No significant effect was found for high-strain work (ie, high psychosocial job demands and low job control), but a relationship was found between passive work (ie, low psychosocial job demands and low job control) and mortality (OR, 1.35, 1.06-1.72). No significant risk of death was found for psychosocial or physical job demands, job security, or work-related social support. Retirement (OR, 2.85, 1.59-5.11) and unemployment (OR, 2.26, 1.65-3.10) transitions and baseline disability (OR, 1.38, 1.06-1.79) predicted mortality.

CONCLUSIONS

The results support the importance of job control to health. The passive work effect suggests that job content may be important in shaping a worker's health over the life course. Future research should focus on modeling stressors over the life course to capture the dynamic interplay of life transitions, stressor intensity and duration and the role of health in the interplay.

Sectional imaging anatomy: pelvic ring ligaments

The purpose of this article is to describe the complex anatomy of the pelvic ligaments. It uses schematics to display 10 color-coded ligaments in relation to the bony architecture. This atlas and the accompanying summary of the classification of pelvic ligamentous injuries is designed to encourage the use of magnetic resonance imaging in cases of pelvic ring trauma.

Regional differences in functional receptor distribution and calcium mobilization in the intact human lens

PURPOSE

To investigate regional differences in Ca(2+) mobilization kinetics in the intact human lens produced by exposure to agonists of tyrosine-kinase and G-protein-coupled receptors and to characterize the major receptor subtypes involved in Ca(2+) signaling in the different regions.

METHODS

Whole human lenses were placed anterior side down in a plastic chamber and perifused with artificial aqueous humor (AAH) at 30 degrees C. After fura-2 incorporation, cytosolic Ca(2+) levels were monitored by using epifluorescence techniques in either the equatorial or central anterior epithelial cells of the intact lens. Agonists dissolved in AAH were applied to the lens in successive short pulses.

RESULTS

Central anterior lens epithelial cells produced a large response to 10 microM acetylcholine (ACh) and histamine; only a small response to adenosine triphosphate (ATP); and no response to 10 microM adrenalin, 10 ng/ml epithelial growth factor (EGF) or TGF alpha, or 50 ng/ml platelet-derived growth factor (PDGF)-AB. Conversely, the equatorial cells produced a strong response to 10 microM ATP and histamine, 10 ng/ml EGF (or TGF alpha), and 50 ng/ml PDGF-AB, but failed to respond to 10 microM ACh or 10 microM adrenalin. The EGF-induced response in the equatorial cells was blocked completely by tyrphostin (AG1478), a specific inhibitor of the EGF receptor tyrosine kinase. Carbachol, a nonhydrolyzable analogue of ACh, and pilocarpine, the M1 muscarinic receptor-specific agonist, both produced the same trend of response amplitude elicited by ACh in each region of the lens. The potency order of purinergic agonist-induced Ca(2+) mobilization at the equator was consistent with the P2Y(2) receptor subtype. The histamine-induced response was abolished by 10 microM triprolidine, a specific H(1) receptor antagonist, but remained unaffected by the specific H(2) and H(3) antagonists, ranitidine and thioperamide, respectively. CONCLUSIONS. There is a spatial heterogeneity in functional receptor activity in different regions of the whole lens. The important growth factor receptors for EGF and PDGF are functionally active only in the equatorial cells of the mature human lens. This study further shows that the ACh, histamine, and ATP-induced responses arise from the activation of M1 muscarinic, H(1) histamine, and P2Y(2) purinergic receptors, respectively.

Sectional neuroanatomy of the lower limb II: leg and foot

The authors have produced a pair of articles that can be used to rapidly identify back, hip, and lower limb muscles and their innervation(s). This article presents the motor and sensory innervation of the lower limb by color-coding structures to match their peripheral nerves. It provides a companion summary table that allows prediction of unique patterns of denervation from 12 lesions sites.