Inactivation of TMEM106A promotes lipopolysaccharide-induced inflammation via the MAPK and NF-κB signaling pathways in macrophages.

Pattern recognition receptors, such as Toll-like receptors (TLRs), play an important role in the host defense against invading microbial pathogens. Their activation must be precisely regulated, as inappropriate activation or overactivation of TLR signaling pathways may result in inflammatory disorders, such as septic shock or autoimmune diseases. TMEM106A is a type II transmembrane protein constitutively expressed in macrophages. Our current study demonstrated that TMEM106A levels were increased in macrophages upon lipopolysaccharide (LPS) stimulation, as well as in the peripheral monocytes of patients with sepsis. Tmem106a knockout mice were more sensitive to lipopolysaccharide (LPS)-induced septic shock than wild-type mice. Further experiments indicated that Tmem106a ablation enhanced the expression of CD80, CD86 and major histocompatibility complex (MHC)-II in mouse macrophages upon LPS stimulation, accompanied with up-regulation of tumor necrosis factor (TNF)-α, interleukin (IL)-6, interferon (IFN)-ß and inducible nitric oxide synthase (iNOS), indicating the activation of macrophages and polarization towards the M1 inflammatory phenotype. Moreover, elevated mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling were found to be involved in the LPS-induced inflammatory response in Tmem106a-/- macrophages. However, this effect was largely abrogated by macrophage deletion in Tmem106a-/- mice. Therefore, deficiency of Tmem106a in macrophages may enhance the M1 polarization in mice, resulting in inflammation. This suggests that TMEM106A plays an important regulatory role in maintaining macrophage homeostasis.

Ranibizumab pretreatment in diabetic vitrectomy: a pilot randomised controlled trial (the RaDiVit study).

PurposeOur aim was to evaluate the impact of intravitreal ranibizumab pretreatment on the outcome of vitrectomy surgery for advanced proliferative diabetic retinopathy. The objective was to determine the feasibility of a subsequent definitive trial and estimate the effect size and variability of the outcome measure.Patients and methodsWe performed a pilot randomised double-masked single-centre clinical trial in 30 participants with tractional retinal detachment associated with proliferative diabetic retinopathy. Seven days prior to vitrectomy surgery, participants were randomly allocated to receive either intravitreal ranibizumab (Lucentis, Novartis Pharmaceuticals UK Ltd, Frimley, UK) or subconjunctival saline (control). The primary outcome was best-corrected visual acuity 12 weeks following surgery.ResultsAt 12 weeks, the mean (SD) visual acuity was 46.7 (25) ETDRS letters in the control group and 52.6 (21) letters in the ranibizumab group. Mean visual acuity improved by 14 (31) letters in the control group and by 24 (27) letters in the ranibizumab group. We found no difference in the progression of tractional retinal detachment prior to surgery, the duration of surgery, or its technical difficulty. Vitreous cavity haemorrhage persisted at 12 weeks in two of the control group but none of the ranibizumab group.ConclusionRanibizumab pretreatment may improve the outcome of vitrectomy surgery for advanced proliferative diabetic retinopathy by reducing the extent of post-operative vitreous cavity haemorrhage. However, the effect size appears to be modest; we calculate that a definitive study to establish a minimally important difference of 5.9 letters at a significance level of P<0.05 would require 348 subjects in each arm.

Reduced levels of human apoE4 protein in an animal model of cognitive impairment.

The APOE4 allele is the most common genetic determinant for Alzheimer's disease (AD) in the developed world. APOE genotype specific differences in brain apolipoprotein E protein levels have been observed in numerous studies since the discovery of APOE4's link to AD. Since the human apoE4 targeted replacement mice display characteristics of cognitive impairment we sought to determine if reduced levels of apoE might provide one explanation for this impairment. We developed a novel mass spectrometry method to measure apoE protein levels in plasma. Additionally, we developed an ELISA that replicates the mass spectrometry data and enables the rapid quantitation of apoE in plasma, brain and cerebrospinal fluid. We detected a significant decrease in plasma, brain and cerebrospinal fluid apoE levels in the apoE4 mice compared to apoE2 and E3 mice. We also measured a small (∼19%) decrease in brain apoE levels from aged, non-demented APOE4 carriers. Our findings suggest that a fraction of APOE4-linked AD may be due to insufficient levels of functional apoE required to maintain neuronal health.

Simultaneous extrusion and intrusion of a scleral buckle in a patient with Marfan's syndrome.

An Asian male in his late 50s with known Marfan's syndrome (MFS) presented with sudden deterioration in vision and loss of globe structure 13 years after the placement of a silicone scleral encircling band for the management of retinal detachment. Surgical exploration revealed simultaneous intrusion and extrusion of the encircling band resulting in globe perforation and collapse. This was managed by removal of the encircling band and a scleral patch graft over the defect. This case highlights that in patients with thin sclera, such as in MFS, scleral perforation is a potential complication that should be considered in patients undergoing scleral buckling. Management of this complication is also technically difficult because of impaired healing of the sclera in these patients.

Progressive loss of synaptic integrity in human apolipoprotein E4 targeted replacement mice and attenuation by apolipoprotein E2.

Inheritance of the APOE4 allele is a well established genetic risk factor linked to the development of late onset Alzheimer's disease. As the major lipid transport protein in the central nervous system, apolipoprotein (apo) E plays an important role in the assembly and maintenance of synaptic connections. Our previous work showed that 7 month old human apoE4 targeted replacement (TR) mice displayed significant synaptic deficits in the principal neurons of the lateral amygdala, a region that is critical for memory formation and also one of the primary regions affected in Alzheimer's disease, compared to apoE3 TR mice. In the current study, we determined how age and varying APOE genotype affect synaptic integrity of amygdala neurons by comparing electrophysiological and morphometric properties in C57BL6, apoE knockout, and human apoE3, E4 and E2/4 TR mice at 1 month and 7 months. The apoE4 TR mice exhibited the lowest level of excitatory synaptic activity and dendritic arbor compared to other cohorts at both ages, and became progressively worse by 7 months. In contrast, the apoE3 TR mice exhibited the highest synaptic activity and dendritic arbor of all cohorts at both ages. C57BL6 mice displayed virtually identical synaptic activity to apoE3 TR mice at 1 month; however this activity decreased by 7 months. ApoE knockout mice exhibited a similar synaptic activity profile with apoE4 TR mice at 7 months. Consistent with previous reports that APOE2 confers protection, the apoE4-dependent deficits in excitatory activity were significantly attenuated in apoE2/4 TR mice at both ages. These findings demonstrate that expression of human apoE4 contributes to functional deficits in the amygdala very early in development and may be responsible for altering neuronal circuitry that eventually leads to cognitive and affective disorders later in life.

Use of hydroxypropylmethylcellulose 2% for removing adherent silicone oil from silicone intraocular lenses.

BACKGROUND/AIMS: To investigate the effect of hydroxypropylmethylcellulose (HPMC) on the physical interaction (contact angle) between silicone oil and a silicone intraocular lens (IOL). METHODS: In vitro experiments were performed, to determine the effect of HPMC (0.5%, 1% or 2%), with or without an additional simple mechanical manoeuvre, on the contact angle of silicone oil at the surface of both silicone and acrylic (control) IOLs. A balanced salt solution chamber was used. The study group comprised 21 silicone and nine acrylic IOLs. RESULTS: The median contact angle of silicone oil on silicone IOL was 99 degrees. The addition of HPMC 2% alone did not significantly alter the contact angle. HPMC 2% combined with an additional single mechanical manoeuvre increased the contact angle to 180 degrees (greater non-wetting), with complete separation of silicone oil from silicone IOL within 1 min. The manoeuvre alone, or in conjunction with a lower concentration of HPMC (0.5 or 1%), was ineffective in increasing the contact angle. CONCLUSION: We present a novel, non-toxic technique of using hydroxypropylmethylcellulose 2% combined with a simple mechanical manoeuvre, for the removal of adherent silicone oil droplets from silicone intraocular lenses.

APOE genotype affects outcome in a murine model of sepsis: implications for a new treatment strategy.

In this study, we assessed whether apolipoprotein E (APOE) polymorphism affects inflammatory responses and mortality in the caecal ligation and puncture model of peritonitis. In addition, we determined the effects of APOE mimetic peptide administration in this sepsis model. Differences in survival between targeted replacement mice expressing the human APOE3 allele (APOE3TR) and the APOE4 allele (APOE4TR) mice were assessed. In a separate series of experiments, COG1410, an apoE-mimetic peptide, was administered intravenously at 12-hour intervals for 72 hours and compared to vehicle-treated control animals. End-points included mortality and serum levels of interleukin-1beta, interleukin-6, interleukin-12 and tumour necrosis factor-alpha. Mice expressing the human APOE4 allele (n = 16) demonstrated an increase in mortality following caecal ligation and puncture compared with APOE3TR mice (n = 22; P = 0.039). Administration of the apolipoprotein E mimetic COG1410 was well tolerated and APOE3TR mice treated with peptide (n = 20) demonstrated a significant reduction in mortality compared with vehicle treated animals (n = 20; P = 0.007). A similar effect was also observed in APOE4TR animals, in which treatment with COG1410 was associated with reduced mortality compared with vehicle treatment (n =16 animals/group; P = 0.027). COG1410 was also associated with a reduction in TNFalpha, interleukin-1beta, interleukin-6 and interleukin-12 levels in both APOE3TR and APOE4TR (n = 5 animals/group) assessed at 24 hours. Thus, administration of an apolipoprotein E-mimetic peptide is well tolerated, suppresses inflammatory responses, and improves mortality in a caecal ligation and puncture model of sepsis.

Towards a better understanding of patient perspectives of clinical teaching in ophthalmology.

OBJECTIVE: To investigate of the perspectives of ophthalmology patients involved in clinical teaching. METHODS: In all, 26 patients attending a revision course for postgraduate Membership of the Royal College of Ophthalmologists examination were recruited. Every patient was examined by each of 36 residents who were present on this course making a total of 936 clinical examinations. Patient perspectives on their experience were investigated using a questionnaire. Four domains were investigated: interpersonal aspects, information exchange, discomfort, and overall perceptions. RESULTS: Four different examinations were carried out: neurological, orthoptic and slit-lamp examination of the anterior or posterior segment. The overwhelming proportion of patients learned much about their condition and felt that their contribution towards the training was valuable. Patients found the experience to be positive and satisfying, and all of the patients expressed a desire to reattend. No significant difference in patient discomfort (P=0.36) or perceptions of rough handling by doctors (P=0.62) between patients undergoing slit-lamp examination or non-slit-lamp examination was evident. CONCLUSIONS: Patients are willing to participate in clinical teaching and assessment, and they gain from the experience. Patients undergoing examinations using high luminance light sources were no more affected by discomfort than those undergoing eye movement or neurological examinations. Our data demonstrate the argument for a greater role of patient-based teaching as a training and assessment tool for fundoscopy.

Transcriptional profiling and pathway analysis of monosodium iodoacetate-induced experimental osteoarthritis in rats: relevance to human disease.

OBJECTIVE: The objective of this study was to characterize the rat monosodium iodoacetate (MIA)-induced model for osteoarthritis (OA) and determine the translatability of this model to human disease. This was accomplished through pathway, network and system level comparisons of transcriptional profiles generated from animal and human disease cartilage. METHODS: An OA phenotype was induced in rat femorotibial joints following a single injection of 200mug MIA per knee joint for a period of 2 or 4 weeks. Lesion formation in the rat joints was confirmed by histology. Gene expression changes were measured using the Agilent rat whole genome microarrays. Cartilage was harvested from human knees and gene expression changes were measured using the Agilent human arrays. RESULTS: One thousand nine hundred and forty-three oligos were differentially expressed in the MIA model, of these, approximately two-thirds were up-regulated. In contrast, of the 2130 differentially expressed oligos in human disease tissue, approximately two-thirds were down-regulated. This dramatic difference was observed throughout each level of the comparison. The total overlap of genes modulated in the same direction between rat and human was less than 4%. Matrix degradation and inflammatory genes were differentially regulated to a much greater extent in MIA than human disease tissue. CONCLUSION: This study demonstrated, through multiple levels of analysis, that little transcriptional similarity exists between rat MIA and human OA derived cartilage. As disease modulatory activities for potential therapeutic agents often do not translate from animal models to human disease, this and like studies may provide a basis for understanding the discrepancies.

Vitreoretinal surgery after childhood ocular trauma.

AIM: In adults modern vitreoretinal surgery allows many traumatised eyes to be salvaged. However, one third of serious eye injuries occur in the paediatric age group and trauma is a leading cause of monocular blindness in childhood. This study aims to report the indications, complications and outcomes for vitreoretinal surgical intervention after childhood ocular trauma. METHODS: Retrospective case note review of 61 children (age 16 years or less) undergoing vitreoretinal surgical procedures following ocular trauma at a tertiary referral centre. RESULTS: Twenty-eight children (45.9%) had open globe injuries (OGI) and 33 closed globe injuries (CGI, 54.1%). The mean age of children with OGI was 9.5 years and with CGI 12.3 years (P=0.0068). Forty-seven children had traumatic retinal detachments (77.1%), which in 17 cases were treated with conventional scleral buckling surgery and in 30 by vitrectomy. Retinal re-attachment was achieved after one procedure in 70.6% with scleral buckling and 46.7% with vitrectomy. Fourteen children (22.9%) had attached retinas but required vitrectomy for other reasons. After a mean follow-up of 19.6 months, the median visual acuity (VA) of the children improved from counting fingers at presentation to 6/36 at final review (P=0.0031). Traumatic retinal detachment requiring vitrectomy was associated with poor visual outcome (P=0.0003). CONCLUSION: Vitreoretinal intervention resulted in an improvement in vision in 32 children (57.1%) and stabilised 11 at their presenting acuity (19.6%). Two thirds of the children attained a final VA of 6/60 or better. Proliferative vitreoretinopathy was the cause of redetachment in 68.2% of cases and was significantly associated with a poor outcome (P<0.0001).

An apolipoprotein E-based therapeutic improves outcome and reduces Alzheimer's disease pathology following closed head injury: evidence of pharmacogenomic interaction.

Apolipoprotein E (apoE) modifies glial activation and the CNS inflammatory response in an isoform-specific manner. Peptides derived from the receptor-binding region of apoE have been demonstrated to maintain the functional activity of the intact protein, and to improve histological and functional deficits after closed head injury. In the current study, APOE2, APOE3, and APOE4 targeted replacement (TR) mice expressing the human apoE protein isoforms (apoE2, apoE3 and apoE4) were used in a clinically relevant model of closed head injury to assess the interaction between the humanized apoE background and the therapeutic apoE mimetic peptide, apoE(133-149). Treatment with the apoE-mimetic peptide reduced microglial activation and early inflammatory events in all of the targeted replacement animals and was associated with histological and functional improvement in the APOE2TR and APOE3TR animals. Similarly, brain beta amyloid protein (Abeta)(1-42) levels were increased as a function of head injury in all of the targeted replacement mice, while treatment with apoE peptide suppressed Abeta(1-42) levels in the APOE2TR and APOE3TR animals. These results suggest a pharmacogenomic interaction between the therapeutic effects of the apoE mimetic peptide and the human apoE protein isoforms. Furthermore, they suggest that administration of apoE-mimetic peptides may serve as a novel therapeutic strategy for the treatment of acute and chronic neurological disease.

Apolipoprotein E allele-dependent pathogenesis: a model for age-related retinal degeneration.

Age-related macular degeneration (AMD) is a late-onset, multifactorial, neurodegenerative disease of the retina and the leading cause of irreversible vision loss in the elderly in the Western world. We describe here a murine model that combines three known AMD risk factors: advanced age, high fat cholesterol-rich (HF-C) diet, and apolipoprotein E (apoE) genotype. Eyes of aged, targeted replacement mice expressing human apoE2, apoE3, or apoE4 and maintained on a HF-C diet show apoE isoform-dependent pathologies of differential severity. ApoE4 mice are the most severely affected. They develop a constellation of changes that mimic the pathology associated with human AMD. These alterations include diffuse sub-retinal pigment epithelial deposits, drusenoid deposits, thickened Bruch's membrane, and atrophy, hypopigmentation, and hyperpigmentation of the retinal pigment epithelium. In extreme cases, apoE4 mice also develop marked choroidal neovascularization, a hallmark of exudative AMD. Neither age nor HF-C diet alone is sufficient to elicit these changes. We document choroidal neovascularization and other AMD-like ocular pathologies in an animal model that exploits known AMD risk factors. The model is additionally attractive because it is not complicated by invasive experimental intervention. Our findings in this model implicate the human apoE E4 allele as a susceptibility gene for AMD and support the hypothesis that common pathogenic mechanisms may underlie AMD and Alzheimer's disease.

Total hip arthroplasty with cement and without acetabular bone graft for severe hip dysplasia. A concise follow-up, at a minimum of twenty years, of a previous report.

We previously evaluated a cohort of fifty-three patients with severe hip dysplasia (Crowe Type-II, III, or IV subluxation) who underwent a total of sixty-six Charnley total hip arthroplasties. The acetabular component was placed at the anatomic hip center, the superolateral defect was filled with cement, and no bone-grafting was used to supplement the acetabular wall. All but one patient, who was lost to follow-up, were followed until death or for a minimum of twenty years. Radiographic and functional follow-up data were collected prospectively. This retrospective review included twenty-four patients (thirty-four hips) who were alive at a minimum of twenty years following the surgery. Fourteen (22%) of the sixty-five hips underwent revision of a component, with eleven of the revisions performed because of aseptic loosening. Eight of those eleven hips underwent revision because of acetabular loosening alone; two, because of femoral loosening alone; and one, because of loosening of both components. The combined prevalence of revision because of aseptic loosening of the acetabular component and radiographic evidence of failure of the acetabular component was 28% (eighteen hips). With the numbers available, the need for acetabular revision was not associated with the percentage of cement coverage (p = 0.362) or the Crowe classification (p = 0.159). At a minimum of twenty years postoperatively, the survivorship of the acetabular component was 86% +/- 8% with revision because of aseptic loosening as the end point and 82% +/- 10% with revision because of aseptic loosening or radiographic evidence of loosening as the end point. The results that we evaluated at a minimum of twenty years after use of this technique can be compared with the results of other techniques in studies with similar long-term follow-up periods.

Retinal detachment following surgery for congenital cataract: presentation and outcomes.

AIMS: To review the current management and outcomes of retinal detachment following cataract surgery in childhood. METHODS: A retrospective review of 59 eyes of 52 patients. RESULTS: In 37% of patients, the fellow eye was blind (<3/60). The macula was detached at presentation in 81% of eyes. The detachment was obscured by residual lens matter, or a miotic pupil in 67% of eyes that had cataract surgery before 1970, but in only 30% of eyes operated after 1970. The retina was reattached with one operation in 59% of eyes, and final reattachment was achieved in 81%. No retina was reattached by scleral buckling alone. Visual outcomes were slightly better in eyes that had retinal detachment repair after 1 January 1998. Nine patients were blind in both eyes at the latest follow-up. CONCLUSIONS: Retinal detachment following childhood cataract surgery remains a serious condition. There has been some improvement in the prognosis due to a combination of advances in childhood cataract surgery as well as to improvements in the management of retinal detachment. Early recognition and prompt surgery, using an internal approach, may prevent blindness in most cases.

Marked regional differences of brain human apolipoprotein E expression in targeted replacement mice.

We used three human apolipoprotein (apo) E targeted replacement mouse lines, each expressing one of the three common human apoE isoforms to study the pattern of apoE expression in the central nervous system (CNS). Immunocytochemistry on brain sections from all three lines of targeted replacement mice, wild type mice, African green monkeys, and humans show a predominantly glial pattern of apoE expression. The levels of human apoE protein in hippocampus and frontal cortex were similar between targeted replacement mice and non-demented human tissue. Within a given brain region, the levels of apoE were very similar amongst all three isoforms, which contrasts sharply with plasma, where apoE2 levels are 16-fold higher than apoE3 and E4 levels. Across brain regions, cerebellar apoE levels were significantly higher than cerebral apoE levels. In conclusion, we provide detailed analysis of a human apoE animal model system that recapitulates both the pattern and level of apoE expression in non-demented humans. The neurobiology of human apoE isoforms can now be studied in both the normal and post-injury state, since all apoE regulatory sequences are intact. Finally, the differences in apoE levels we observed may explain the regional vulnerability of neuronal degeneration in Alzheimer's disease.

Impaction allografting with cement for extensive femoral bone loss in revision hip surgery: a 4- to 8-year follow-up study.

The current study evaluates the 4- to 8-year results of 26 cemented femoral revisions with impaction allografting using a collared femoral component in cases of extensive femoral bone loss. Patients were followed prospectively and were evaluated at an average of 6.0 years after the allograft revision procedure. The average age at the time of surgery was 69.3 years. At final follow-up, 20 patients (20 hips) were living, and 6 patients (6 hips) were deceased. No femoral component rerevisions were performed for any reason in any patient, and none were radiographically loose at final follow-up. There was 1 subsided femoral component of <5 mm, 3 postoperative periprosthetic femoral fractures, and a greater trochanter nonunion rate of 32%. At the current follow-up interval, these cemented femoral revisions with impaction allografting have performed well with excellent clinical and radiographic durability in this difficult patient population. The prevalence of periprosthetic fracture is a significant concern. This study shows durable results using the impaction allografting technique in cases of severe bone loss.

Revision of a cemented acetabular component to a cementless acetabular component. A ten to fourteen-year follow-up study.

BACKGROUND: Although cementless acetabular components are routinely used in revision hip surgery, few investigators have evaluated the retention and efficacy of these components in the long term. In the current study, the clinical and radiographic outcomes of a series of arthroplasties performed by one surgeon with a cementless acetabular component were assessed at a minimum of ten years. METHODS: From 1986 through 1988, sixty-one consecutive revision total hip arthroplasties were performed in fifty-five patients because of aseptic failure of one or both components of a prosthesis in which both components had been cemented. Twenty-eight patients (thirty-two hips) were alive at a mean of 12.9 years (range, 11.5 to 14.3 years) after the operation. In all of the patients, the acetabular component was revised to a porous-coated Harris-Galante component inserted without cement, and the femoral component was revised to an Iowa component affixed with contemporary cementing techniques. The hips were evaluated clinically and radiographically at a minimum of ten years subsequent to the index revision. No hips were lost to follow-up. RESULTS: None of the acetabular components required revision because of aseptic loosening. Two hips (3%) demonstrated radiographic evidence of aseptic loosening of the acetabular component. The polyethylene liner was exchanged during the follow-up period in eight hips. CONCLUSION: After a minimum of ten years of follow-up, cementless acetabular fixation in revision hip arthroplasty had produced durable results that were markedly better than those reported for acetabular fixation with cement.

Dislocation after total hip arthroplasty: a single surgeon's experience.

The purpose of this article is to evaluate the dislocations that occurred in a single surgeon practice over a 26 year period. After extensive research, the authors concluded that dislocation continues to occur long after the initial arthroplasty procedure. Patients should be aware that more than a quarter of dislocations occur 2 years following surgery. Use of modular 22 millimeter components were associated with the highest dislocation rate. These components should be used very cautiously. Constrained liners have helped decrease the dislocation rate following revision for dislocation.