Modulating Excited State Properties and Ligand Ejection Kinetics in Ruthenium Polypyridyl Complexes Designed to Mimic Photochemotherapeutics.

Ruthenium(II) polypyridyl complexes have gained significant interest as photochemotherapeutics (PCTs) due to their synthetic viability, strong light absorption, well understood excited state properties, and high phototoxicity indexes. Herein, we report the synthesis, characterization, electrochemical, spectrochemical, and preliminary cytotoxicity analyses of three series of ruthenium(II) polypyridyl complexes designed to mimic PCTs. The three series have the general structure of [Ru(bpy)2(N-N)]2+ (Series 1), [Ru(bpy)(dmb)(N-N)]2+ (Series 2), and [Ru(dmb)2(N-N)]2+ (Series 3, where N-N is a bidentate polypyridyl ligand, bpy = 2,2'-bipyridine, and dmb = 6,6'-dimethyl-2,2'-bipyridine). In the three series, the N-N ligand was systematically modified to incorporate increased conjugation and/or electronegative heteroatoms to increase dπ-π* backbonding, red-shifting the lowest energy metal-to-ligand charge transfer (MLCT) absorptions from λmax = 454 to λmax = 580 nm, nearing the therapeutic window for PCTs (600-1100 nm). In addition, steric bulk was systematically introduced through the series, distorting the Ru(II) octahedra, making the dissociative 3dd* state thermally accessible at room and body temperatures. This resulted in a 4 orders of magnitude increase in photoinduced ligand ejection kinetics, and demonstrates the ability to modulate both the MLCT* and dd* manifolds in the complexes, which is critical in PCT drug design. Preliminary cell viability assays suggest that the increased steric bulk to lower the 3dd* states may interfere with the cytotoxicity mechanism, limiting photoinitiated toxicity of the complexes. This work demonstrates the importance of understanding both the MLCT* and dd* manifolds and how they impact the ability of a complex to act as a PCT agent.

Monitoring liver transplant rates in persons diagnosed with hepatitis C: a data linkage study, England 2008 to 2017.

IntroductionLiver transplantation is an important measure of burden from hepatitis C virus (HCV)-associated liver disease.AimsTo describe transplant rates and survival in individuals with HCV infection from 2008 to 2017 in England through data linkage.MethodsThis is a retrospective observational cohort study. Laboratory reports of HCV infection were linked to the Liver Transplant Registry for individuals aged 15 years and over, first diagnosed between 1998 and 2017. We estimated age-sex standardised incidence rates and used Poisson regression to investigate predictors of liver transplantation and test for a change in incidence after introduction of direct-acting antivirals (DAAs) in 2014. Kaplan-Meier survival analysis was used to calculate post-transplant survival rates.ResultsOf 124,238 individuals diagnosed with HCV infection, 1,480 were registered and 1,217 received a liver transplant. Of individuals registered, 1,395 had post-HCV cirrhosis and 636 had hepatocellular carcinoma (618 also had post-HCV cirrhosis). Median time from HCV diagnosis to transplant was 3.4 years (interquartile range: 1.3-6.8 years). Liver transplant rates were lower 2014-17 compared with 2011-13 (incidence rate ratio: 0.64; 95% confidence interval: 0.55-0.76). Survival rates were 93.4%, 79.9% and 67.9% at 1, 5 and 10 years, respectively. Data linkage showed minimal under-reporting of HCV in the transplant registry.ConclusionIn the post-DAA era, liver transplant rates have fallen in individuals with HCV infection, showing early impact of HCV treatment scale-up; but the short time from HCV diagnosis to liver transplant suggests late diagnosis is a problem.

Mapping the hepatitis C cascade of care in people attending drug treatment services in England: A data linkage study.

INTRODUCTION: Hepatitis C (HCV) infection in England primarily affects people who inject drugs (PWID). We describe persons HCV tested, estimate incidence and establish the cascade of care (CoC) for people engaging with drug services. METHODS: Persons testing for HCV in drug services in Sentinel Surveillance of Blood Borne Virus Testing (SSBBV) between 2008 and 2016 were linked with people attending drug services in the National Drug and Treatment Monitoring System (NDTMS). We describe risk characteristics, establish the CoC, and estimate HCV incidence in PWID diagnosed in drug services. RESULTS: Of 46,721 persons tested for anti-HCV in SSBBV in drug services, 29,773 (63.7%) linked to NDTMS. Of these, 9100 (30.6%) were antiV positive and anti-HCV positivity was 45.0% in persons reporting urgent housing problems and 43.8% in persons reporting ever injecting. Among persons anti-HCV positive, half had ≥1 positive anti-HCV test. For persons' first anti-HCV positive between 2008 and 2013 (n = 3123), 74.9% were HCV RNA tested, of whom 71.2% were RNA positive, and of these, 14.0% had evidence of interferon-based treatment, with 52.8% achieving cure. Among PWID, HCV incidence was 8.7 per 100 person-years (95% CI: 8.1-9.2). CONCLUSION: Through record linkage of surveillance datasets, we estimated the HCV CoC for people attending drug services, providing a benchmark from which to monitor the impact of strategies to scale-up prevention, testing, and curative treatment with direct acting antivirals. Our study highlights wasteful repeated testing and poor linkage to care for this high risk population which need to be addressed.

HIV coinfection among persons diagnosed with hepatitis B in England in 2008-2014.

OBJECTIVES: The aim of the study was to estimate HIV prevalence among persons with hepatitis B virus (HBV) infection in England and to examine associated risk factors. METHODS: Persons aged ≥ 15 years with an HBV surface antigen (HBsAg) test reported to Public Health England (PHE) sentinel surveillance during 2008-2014 were linked to the PHE national HIV/AIDS database. Coinfection was defined as an HIV diagnosis prior to, or within 6 months following, a positive HBsAg test. RESULTS: During 2008-2014, 2 149 933 persons were tested for HBsAg and 3.9% (1129 of 28 789) of HBsAg-positive persons were HIV positive. The probable route of HIV infection was heterosexual exposure for 95.3% of female patients and 32.3% of male patients, with 61.5% of male patients reporting sex between men. Among African-born coinfected persons, 84% probably acquired HIV there. Predictors of HIV positivity included older age [adjusted odds ratio (aOR) 1.1] and being of black ethnicity (aOR 15.5 for males; aOR 16.4 for females) or being male and of white ethnicity (aOR 8.2) compared with being female and of white ethnicity. HIV coinfection was more likely when HBV was diagnosed in sexual health (aOR 55.0), specialist liver (aOR 6.7), emergency department (aOR 5.3) and renal services (aOR 2.8) compared with general practice. Most (60.4%; 682 of 1129) coinfected persons were diagnosed with HIV infection > 6 months before HBV diagnosis. CONCLUSIONS: Persons testing positive for HBsAg had a low HIV infection rate and fell largely into two groups: those of black ethnicity with probable Africa-acquired infections and white men who have sex with men (MSM) with probable UK-acquired infections. Findings reinforce existing recommendations to sustain and improve both HBV testing of migrants from HBV-prevalent countries and vaccination among HIV-positive MSM. Findings also support blood-borne virus testing in sexual health services and emergency departments.

Prevalence of diagnosed HIV infection among persons with hepatitis C virus infection: England, 2008-2014.

OBJECTIVES: In persons with hepatitis C virus (HCV) infection, HIV coinfection leads to faster progression to advanced liver disease. The aim of our study was to estimate diagnosed HIV prevalence among people with evidence of current HCV infection (polymerase chain reaction positive) and examine predictors of coinfection. METHODS: Adults (≥ 15 years old) with a current HCV infection reported to the Public Health England (PHE) sentinel surveillance of blood-borne viruses were linked to the PHE national HIV database using a deterministic methodology. Descriptive and multivariate analyses were conducted. RESULTS: Between 2008 and 2014, 5.0% (999/20 088) of adults with a current HCV infection were diagnosed with HIV coinfection. The majority acquired HIV through sex between men (441; 64.9%), followed by injecting drug use (153; 22.5%) and heterosexual contact (84; 12.4%). Of persons who were coinfected, 65.5% had been diagnosed with HIV infection > 6 months before their HCV diagnosis, 41.4% of whom had a negative anti-HCV test between their HIV and HCV diagnoses. In a multivariable model among persons with current HCV infection, an HIV diagnosis was more likely among men [adjusted odds ratio (aOR) 3.29; 95% confidence interval (CI) 2.60-4.16] and persons of black ethnicity (aOR 3.19; 95% CI 1.36-7.46), and less likely among older adults (aOR 0.85 per 10-year increase; 95% CI 0.79-0.92) and persons of Asian ethnicity (aOR 0.59; 95% CI 0.41-0.86). CONCLUSIONS: Our results indicate that the majority of diagnosed HIV and current HCV coinfections are among men who have sex with men. Safer sex campaigns should include awareness of transmission of HCV among MSM living with HIV.

Where do we diagnose HIV infection? Monitoring new diagnoses made in nontraditional settings in England, Wales and Northern Ireland.

OBJECTIVES: The objectives of the study were to describe 10-year trends in HIV diagnosis setting and to explore predictors of being diagnosed outside a sexual health clinic (SHC). METHODS: Analyses of national HIV surveillance data were restricted to adults (aged ≥ 15 years) diagnosed in 2005-2014 in England, Wales and Northern Ireland. Logistic regression identified factors associated with diagnosis outside an SHC (2011-2014). RESULTS: Between 2005 and 2014, 63 599 adults were newly diagnosed with HIV infection; 83% had a diagnosis setting reported. Most people were diagnosed in SHCs (69%) followed by: medical admissions/accident and emergency (A&E; 8.6%), general practice (6.4%), antenatal services (5.5%), out-patient services (3.6%), infectious disease units (2.7%) and other settings (4.0%). The proportion of people diagnosed outside SHCs increased from 2005 to 2014, overall (from 27% to 32%, respectively) and among men who have sex with men (MSM) (from 14% to 21%) and black African men (from 25% to 37%) and women (from 39% to 52%) (all trend P < 0.001). Median CD4 increased across all settings, but was highest in SHCs (384 cells/µL) and lowest in medical admissions/A&E (94 cells/µL). Predictors of being diagnosed outside SHCs included: acquiring HIV through heterosexual contact [adjusted odds ratio (aOR) 1.99; 95% confidence interval (CI) 1.81-2.18] or injecting drug use (aOR: 3.28; 95% CI: 2.56-4.19; reference: MSM), being diagnosed late (< 350 cells/µL) (aOR: 2.55; 95% CI: 2.36-2.74; reference: diagnosed promptly) and being of older age at diagnosis (35-49 years: aOR: 1.60; 95% CI: 1.39-1.83; ≥ 50 years: aOR: 2.48; 95% CI: 2.13-2.88; reference: 15-24 years). CONCLUSIONS: The proportion of HIV diagnoses made outside SHCs has increased over the past decade in line with evolving HIV testing guidelines. However, the rate of late diagnosis remains high, indicating that further expansion of testing is necessary, as many people may have had missed opportunities for earlier diagnosis.

Establishing the cascade of care for hepatitis C in England-benchmarking to monitor impact of direct acting antivirals.

Little is known about engagement and retention in care of people diagnosed with chronic hepatitis C (HCV) in England. Establishing a cascade of care informs targeted interventions for improving case finding, referral, treatment uptake and retention in care. Using data from the sentinel surveillance of blood-borne virus (SSBBV) testing between 2005 and 2014, we investigate the continuum of care of those tested for HCV in England. Persons ≥1 year old with an anti-HCV test and subsequent RNA tests between 2005 and 2014 reported to SSBBV were collated. We describe the cascade of care, as the patient pathway from a diagnostic test, referral into care, treatment and patient outcomes. Between 2005 and 2014, 2 390 507 samples were tested for anti-HCV, corresponding to 1 766 515 persons. A total of 53 038 persons (35 190 men and 17 165 women) with anti-HCV positive were newly reported to SSBBV. An RNA test was conducted on 77.0% persons who were anti-HCV positive, 72.3% of whom were viraemic (RNA positive) during this time period, 21.4% had evidence of treatment and 3130 49.5% had evidence of a sustained virological response (SVR). In multivariable models, confirmation of viraemia by RNA test varied by age and region/test setting; evidence of treatment varied by age, year of test and region/test setting; and SVR varied by age, year of test and region/setting of test. In conclusion, our findings provide HCV cascade of care estimates prior to the introduction of direct acting antivirals. These findings provide important baseline cascade estimates to benchmark progress towards elimination of HCV as a major public health threat.

Evaluation of hepatitis C testing in men who have sex with men, and associated risk behaviours, in Manchester, UK.

OBJECTIVE: To determine the prevalence of newly diagnosed hepatitis C virus (HCV) and associated risk behaviours among men who have sex with men (MSM) in Manchester. METHOD: A survey among MSM attending four genitourinary medicine clinics in Manchester was carried out over 9 months in 2013. Participants were asked about recent sexual behaviour, recreational drug use and HIV status. All men were offered an HCV test. RESULTS: Overall, 2030 MSM completed a questionnaire and accepted an HCV test. Of whom, 0.9% (18) were newly diagnosed with HCV, including 1.8% (13/735) of HIV-positive MSM, 0.7% (3/440) of MSM of unknown HIV status and 0.2% (2/855) of HIV-negative MSM. HCV positivity was significantly associated with HIV status (p<0.001). When compared with HIV-negative MSM, HIV-positive MSM had higher rates of sharing snorting drug equipment, injecting drugs/'slamming' and using recreational drugs (all p<0.05) but lower rates of five or more sexual partners and insertive unprotected anal intercourse (p<0.05). MSM newly diagnosed with HCV had significantly higher prevalence of unprotected sex, sex with someone HCV positive, fisting, group sex, ever injecting drugs/'slamming' and recreational drug use (p<0.002). CONCLUSIONS: In this survey, HIV-positive MSM had significantly different drug use behaviour which may explain the higher HCV burden. However, HCV was also associated with HIV-negative MSM engaging in high-risk sexual practices. All MSM attending sexual health clinics must have a risk assessment and HCV screening should be offered based on the risk. Further studies are warranted to explore the interplay between HCV and HIV risk associated with drug use versus sexual practices.

Incorporating HIV/hepatitis B virus/hepatitis C virus combined testing into routine blood tests in nine UK Emergency Departments: the "Going Viral" campaign.

OBJECTIVES: Routine HIV screening is recommended in those UK hospitals and primary care settings where the HIV prevalence is > 0.2%. For hepatitis B virus (HBV) and hepatitis C virus (HCV), however, testing is targeted at at-risk groups. We investigated the prevalence of these blood-borne viruses (BBVs) during a routine testing pilot in UK Emergency Departments (EDs). METHODS: During the "Going Viral" campaign (13-19 October 2014), nine UK EDs in areas of high HIV prevalence offered routine tests for HIV, HBV and HCV to adults having blood taken as part of routine care. Patients who tested positive were linked to care. RESULTS: A total of 7807 patients had blood taken during their ED visit; of these, 2118 (27%) were tested for BBVs (range 9-65%). Seventy-one BBV tests were positive (3.4%) with 32 (45.1%) new diagnoses. There were 39 HCV infections (15 newly diagnosed), 17 HIV infections (six newly diagnosed), and 15 HBV infections (11 newly diagnosed). Those aged 25-54 years had the highest prevalence: 2.46% for HCV, 1.36% for HIV and 1.09% for HBV. Assuming the cost per diagnosis is £7, the cost per new case detected would be £988 for HCV, £1351 for HBV and £2478 for HIV. CONCLUSIONS: In the first study in the UK to report prospectively on BBV prevalence in the ED, we identified a high number of new viral hepatitis diagnoses, especially hepatitis C, in addition to the HIV diagnoses. Testing for HIV alone would have missed 54 viral hepatitis diagnoses (26 new), supporting further evaluation of routine BBV testing in UK EDs.

Cellular exchange in an endometriosis-adhesion model using GFP transgenic mice.

BACKGROUND: Endometriosis is a debilitating disease that affects women of reproductive age and may lead to impaired fertility. Cell attachment, invasion of the underlying tissue, and vascular ingrowth are important processes in endometrial lesion development. However, the degree of cellular exchange between host peritoneum and endometrial tissue is unclear. METHODS: An experimental endometriosis model was employed whereby uterine horn fragments from wild-type mice were implanted into genetically identical eGFP (enhanced green fluorescent protein) host mice and vice versa. Hormone sensitivity of the ectopic lesions was assessed and cellular exchange determined histologically. RESULTS: White cyst-like lesions developed from implanted fibrin-rich fragments by day 7. Lesions consisted of a well-developed stroma with glandular and luminal epithelium. Both ovariectomy and treatment with a GnRH agonist, leuprorelin, resulted in the suppression of ectopic lesion growth, whereas estradiol treatment increased the size of the ectopic lesion (4 mice per group on day 14). Ingrowth and outgrowth of blood vessels was apparent as well as the exchange of cells between host peritoneum and lesion. CONCLUSION: These findings support the proposal that there is a close cellular interplay between host peritoneum and ectopic tissue and the suitability of this mouse model to study these interactions.

Remodelling of adipose tissue during experimental omental adhesion formation.

BACKGROUND: Peritoneal adhesions are fibrous bands of tissue connecting normally separated organs and frequently involve the fat-laden greater omentum. Remodelling of fibrin-rich exudate under reduced fibrinolytic conditions is thought to initiate adhesion formation following surgery. It is unclear whether adhesions that involve the omentum develop in a similar manner. To improve understanding of omental adhesion formation, adipose tissue distribution, cell proliferation and procollagen type I gene expression were investigated in a murine surgical model and in established omental adhesions from patients undergoing abdominal surgery. METHODS: Experimental murine omental adhesions and human omental adhesions were analysed for signs of tissue remodelling using histology, immunohistochemistry and in situ hybridization. RESULTS: Murine omental tissue showed intense inflammation and reduced adipose tissue 3-7 days after surgery, but increased cellularity and collagen production. Adipose tissue remodelling was reversible with increased adipose tissue and decreased cell proliferation and procollagen type I gene expression, shown by proliferating cell nuclear antigen immunolocalization and in situ hybridization respectively. Human omental adhesions were heterogeneous, with varying amounts of fibrotic and adipose-rich regions, although most displayed proliferating and collagen-producing cells. CONCLUSION: Omental adhesions are not static scar tissue as traditionally thought, but undergo active adipose tissue remodelling over-time.

Spatial distribution of mast cells in chronic venous leg ulcers.

Chronic venous leg ulcers (CVUs) show chronic inflammation but different pathological changes occur in different parts of the ulcer. There is a lack of re-epithelialisation and defective matrix deposition in the ulcer base but epidermal hyperproliferation and increased matrix deposition in the surrounding skin. The role of mast cells in wound healing, inflammation, fibrosis and epidermal hyperproliferation has been extensively studied but less is known about their role in CVUs. In the present study, we investigated the distribution of mast cells in CVUs with specific consideration of the differences between the ulcer base and the skin surrounding the ulcer. Both histochemical and immunohistological methods were used to detect the mast cell marker tryptase in frozen sections of CVU biopsies. Mast cells were counted in the dermis of normal skin, in the ulcer base and in the skin surrounding the ulcer. Double immunofluorescence staining was used to study the location of mast cells in relation to blood vessels. In normal skin few mast cells were seen in the dermis but none in the epidermis. However in CVUs there was a significant increase in intact and degranulated mast cells in the surrounding skin and ulcer edge (184 per field, p<0.003) of CVUs and a significant reduction in the ulcer base (20.5 per field p<0.05) in comparison to normal skin (61 per field). In CVUs mast cells showed a characteristic location near the epithelial basement membrane whilst mast cell granules and phantom cells (mast cells devoid of granules) were predominantly seen in the epidermis. In the dermis, mast cells were seen associated with blood vessels. The marked increase in mast cells in the surrounding skin of CVUs and depletion of mast cells in the ulcer base could implicate mast cell mediators in the pathological changes in CVUs particularly in the epidermal and vascular changes occurring in the surrounding skin.

Expression of cyclooxygenase isoforms in normal human skin and chronic venous ulcers.

Chronic venous ulcers are an example of abnormal wound healing showing chronic inflammation which together with the underlying vascular pathology results in delayed healing. Prostaglandins are among the most important mediators of inflammation. They have proinflammatory effects, predominantly by affecting the vasculature. Cyclooxygenase (COX) is the rate-limiting enzyme in prostanoid synthesis. It is present in two isoforms: COX-1 (constitutive cyclooxygenase) which is produced in the body to maintain normal haemostatic functions, and COX-2 (inducible cyclooxygenase), which is induced during inflammation in response to cytokines. Using immunoenzymatic labelling and western blot analysis, this study has shown that both COX-1 and COX-2 were up-regulated in chronic venous leg ulcers by comparison with normal human skin. De novo appearance of COX-2 in chronic venous ulcers was demonstrated, which is not seen in normal human skin. The main cellular sources of both COX isoforms are macrophages and endothelial cells. COX-2 is also produced by mast cells and fibroblasts. A COX radioimmunoassay showed up-regulation of COX activity in chronic venous ulcers compared with normal skin (p<0.05). Up-regulation of COX-1 in chronic venous leg ulcers could produce prostacyclin, which contributes to angiogenesis. Thus, inhibition of COX-1 by non-steroidal anti-inflammatory drugs (NSAIDs) could increase the local ischaemia and hypoxia associated with chronic venous ulcers. On the other hand, up-regulation of COX-2 is most likely responsible for the persistent inflammation in chronic venous leg ulcers. COX-2 selective inhibitors could therefore be effective in the treatment of chronic venous ulcers.

Desmosomes are reduced in the mouse uterine luminal epithelium during the preimplantation period of pregnancy: a mechanism for facilitation of implantation.

Dynamic regulation of intercellular junctions is an essential aspect of many developmental, reproductive, and physiological processes. We have shown that expression of the desmosomal protein desmoplakin decreases in the luminal uterine epithelium during the preimplantation period of pregnancy in mice. By the time of implantation (between Days 4.5 and 5 of pregnancy), desmoplakin protein can barely be detected by SDS-PAGE and Western blotting, and by immunocytochemistry, it is restricted to well-spaced, punctate dots at the apicolateral junction. Using confocal XZ series and electron microscope quantitation, both the density and distribution of desmosomes along the lateral cell surfaces of luminal epithelial cells were observed to change during early pregnancy. On Day 1 of pregnancy, desmosomes were found at high density in the apicolateral junctional complex, being present here in 79% of ultrathin sections examined, whereas on Day 5, the density was much reduced (present in only 18% of ultrathin sections examined). Desmosomes were found along the lateral surfaces, at or below the level of the nucleus, in 15% of ultrathin sections examined on Day 1 of pregnancy but in only 1% on Day 5. Desmoplakin mRNA declined during the first 4-5 days of pregnancy, along with the protein, suggesting that these changes are controlled at the level of mRNA. This study shows that desmosomes are regulated during early pregnancy, and we propose that a reduction in desmosome adhesion facilitates penetration of the luminal epithelium by trophoblast cells at implantation.

Expression of nitric oxide synthase isoforms and arginase in normal human skin and chronic venous leg ulcers.

Chronic venous ulcers, an example of abnormal wound healing, show chronic inflammation with defective matrix deposition which together with the underlying vascular pathology, result in delayed healing. L-arginine is known to be metabolized by one of two pathways: nitric oxide synthase (NOS), producing nitric oxide (NO), or arginase, producing ornithine. NO is involved in many pathological conditions including vascular and inflammatory disorders. This study therefore investigated the distribution, level and activity of NOS and arginase in chronic venous ulcers in comparison with normal skin, using immunocytochemistry, western blotting, and enzyme assays. The results demonstrated an increased distribution of both NOS and arginase in chronic venous ulcer tissue compared with normal skin, with inflammatory cells and vascular endothelial cells as the main sources. These data were confirmed by western blot analysis, which showed increased levels of both enzymes in chronic venous ulcers. Moreover, there was significantly increased activity of both total NOS (p<0.04) and inducible NOS (p<0.05) in chronic venous ulcer tissue compared with normal skin, and significantly increased activity of arginase (p<0.01) in chronic venous ulcer tissue in comparison with normal skin. NO is known to combine with hydroxyl free radicals forming peroxynitrite, a potent free radical which causes tissue destruction. NO overexpression in chronic venous ulcers may be involved directly or indirectly (through production of peroxynitrite) in the pathogenesis and delayed healing of chronic venous ulcers, through its effects on vasculature, inflammation, and collagen deposition. Arginase is known to enhance matrix deposition. Thus, increased levels of arginase in chronic venous ulcers could contribute to the pathogenesis of lipodermatosclerosis associated with chronic venous insufficiency, predisposing to the formation of chronic venous ulcers and also to matrix cuff formation around blood vessels.

Centration of donor trephination in human corneal transplantation.

PURPOSE: To develop and evaluate a new method to quantify centration of the trephined donor cornea relative to the limbus. METHODS: After human donor corneas were trephined for penetrating keratoplasty, the remaining corneoscleral discs were stained and subjected to image analysis. The centration of the excised donor cornea relative to the limbus was calculated by measuring their centroids from the "captured" images. RESULTS: Fifty-two corneoscleral discs were analyzed. The average deviation from the centre was 0.32 mm (SD, 0.18 mm). Neither surgeon nor the type of trephine significantly influenced the mean centroid deviation. CONCLUSION: We have developed and evaluated a method to quantify centration of human donor cornea. In a small series, decentration did not correlate significantly with either the surgeon or the trephine.

The alpha isoform of protein kinase C is involved in signaling the response of desmosomes to wounding in cultured epithelial cells.

Initiation of reepithelialization upon wounding is still poorly understood. To enhance this understanding, we focus here on changes in the adhesive state of desmosomes of cultured Madin-Darby canine kidney cells in response to wounding of confluent cell sheets. Previous results show that desmosomal adhesion in Madin-Darby canine kidney cells changes from a calcium-dependent state to calcium independence in confluent cell sheets. We show that this change, which requires culture confluence to develop, is rapidly reversed upon wounding of confluent cell sheets. Moreover, the change to calcium dependence in wound edge cells is propagated to cells hundreds of micrometers away from the wound edge. Rapid transition from calcium independence to calcium dependence also occurs when cells are treated with phorbol esters that activate PKC. PKC inhibitors, including the conventional isoform inhibitor Gö6976, cause rapid transition from calcium dependence to calcium independence, even in subconfluent cells. The cellular location of the alpha isoform of PKC correlates with the calcium dependence of desmosomes. Upon monolayer wounding, PKCalpha translocates rapidly to the cell periphery, becomes Triton X-100 insoluble, and also becomes concentrated in lamellipodia. The PKCalpha translocation upon wounding precedes both the increase in PKC activity in the membrane fraction and the reversion of desmosomes to calcium dependence. Specific depletion of PKCalpha with an antisense oligonucleotide increases the number of cells with calcium-independent desmosomes. These results show that PKCalpha participates in a novel signaling pathway that modulates desmosomal adhesion in response to wounding.

Three dimensional analysis of microaneurysms in the human diabetic retina.

The retinal vasculature of postmortem normal human and diabetic eyes was studied using an immunohistochemical technique in conjunction with confocal laser scanning microscopy. The technique, which stained for von Willebrand factor, allowed both large areas of the retinal vasculature to be visualised and abnormalities to be studied in detail without disturbing the tissue architecture. Only one microaneurysm, defined as any focal capillary dilation, was observed in 10 normal eyes but numerous microaneurysms were seen in 4 out of 5 diabetic retinas; counts varied between 0 and 26 per 0.41 mm2 sample area. Microaneurysms were classified into 3 categories according to morphology: saccular, fusiform and focal bulges. Most were saccular, these having no preferred orientation. The majority of microaneurysms were associated with just 2 vessels suggesting they were unlikely to develop at vascular junctions. The majority were observed to originate from the inner nuclear layer and were therefore in the deeper part of the inner retinal capillary plexus. Variation in the staining of microaneurysms may correlate with endothelial dysfunction seen clinically as dye leakage during fluorescein angiography.

Up-regulation of elastase in acute wounds of healthy aged humans and chronic venous leg ulcers are associated with matrix degradation.

Chronic wound healing states are often associated with aging, and despite the increased number of aged patients with nonhealing wounds, controversy still exists concerning the effects of age on wound repair. Our previous work showed that in both venous ulcers in humans and acute wounds in aged animals, fibronectin, an early component in granulation tissue, is deficient compared to normal skin and acute wounds in healthy young animals, respectively. In the present study, we have determined the protease responsible for fibronectin degradation by analyzing tissue taken from the margins of chronic venous ulcers and standardized acute cutaneous wounds collected from a large cohort of "Health status"-defined aged human subjects (screened as per the SENIEUR protocol). When tissue samples were subjected to fibronectin zymography, the main protease involved in the breakdown of fibronectin in both venous ulcers and acute wounds of elderly subjects was found to be a serine protease with a molecular weight of approximately 30 kd. This protease was identified as neutrophil elastase by immunoblotting. In tissue biopsies, elastase was localized to granulocytes by immunocytochemical techniques and shown to be present in greater quantities in venous ulcers and Day-7 and -14 healing acute wounds of healthy aged subjects relative to those of young subjects. The highest quantities were found in acute wounds of elderly women. Our results suggest that the process of aging in healthy human subjects is associated with an up-regulation of elastase during acute wound healing and that an abnormality in down-regulation of this protease could be partially responsible for the transition to chronic wound healing states in the aged.