Glaucoma after penetrating keratoplasty and keratoprosthesis.

PURPOSE: To compare visual and glaucoma outcomes in patients with known glaucoma after a penetrating keratoplasty (PKP) or a Boston Keratoprosthesis Type 1 (KPro) as a second corneal replacement procedure. DESIGN: Retrospective interventional case series. PARTICIPANTS: Charts of 141 eyes that underwent either a PKP or KPro at the Centre hospitalier de l'Université de Montréal after one failed PKP from 2008 to 2020 were reviewed. Forty-six eyes with preoperative glaucoma were included. METHODS: Data collected included demographics, indication for the initial surgery, best corrected visual acuity (BCVA), concurrent ocular disorders, number of glaucoma medications, need for glaucoma surgery, cup-to-disc ratios (CDRs), mean RNFL thickness, and visual field (VF) characteristics. Primary outcomes were glaucoma progression trends. Secondary outcomes were visual outcomes and need for additional procedures. RESULTS: Mean follow-up was 4.7 years for the PKP and 7.3 for the KPro group (P<0.007). 30.6% of PKP compared to 70.5% of KPro patients were diagnosed with glaucoma preoperatively. Glaucoma worsened similarly in both groups; this is based on an analysis of the number of glaucoma medications, CDR, need for glaucoma surgery, and characteristic VF changes. Patients in the PKP group required significantly more regrafts than patients in the KPro group (31.8 vs. 8.3%; P=0.045). CONCLUSIONS: A preoperative diagnosis of glaucoma does not preclude KPro implantation. In glaucomatous eyes, the disease progressed similarly in both groups. Since both procedures increase the risk of worsening glaucoma, close follow-up is recommended. KPro may decrease the need for further corneal transplantation surgery.

[Long-term changes in pupil size after implantation of an Artisan phakic intraocular lens for correction of high myopia]. / Modifications à long terme du diamètre pupillaire après insertion d'un implant phaque Artisan pour la correction des fortes amétropies myopiques.

PURPOSE: To evaluate the long-term changes in pupil size after implantation of an Artisan phakic intraocular lens for correction of high myopia. PATIENTS AND METHODS: Fourteen myopic eyes of seven patients were included in the study. Pupil size was measured under photopic conditions, under scotopic conditions after 10 min of dark adaptation, and after topical medical mydriasis. The pupil size was measured using the eye image of the OPD scan (Nidek). RESULTS: The mean follow-up was 46 months after surgery. The mean photopic pupil diameter was 2.94+/-0.33 mm (range, 2.54-3.6 mm). The diameter of the scotopic pupil remained less than 6.0 mm in all patients (4.68+/-0.59 mm, with maximal pupil diameter of 5.67 mm). The mean pupil diameter after pharmacological dilation was also reduced (5.39+/-1.08 mm; range, 4.19-7.59 mm), with pupil dilation more than 7 mm in only one patient. CONCLUSION: The iris-fixated intraocular lens mechanically limited pupil dilation in our patients. The long-term reduction in pupil size after Artisan phakic intraocular lens implantation may contribute to the maintenance of the quality of vision in scotopic conditions.

Citizen Involvement in Waste Management: An Application of The STOPER Model via an Informed Consensus Approach.

/ Waste management planning and implementation is not only a technological issue, but a social and political one as well. In this paper, we discuss a proposal to rethink certain aspects about waste management planning and implementation. Specifically, we present a framework whereby the ordinary citizen can proactively and constructively participate in the decision-making process. After briefly discussing the STOPER research team and certain limits inherent in current waste-management practices, we propose a mode of consultation known as the informed consensus approach. We assert that this approach incorporates social perceptions of key intervenors such as experts, decision makers, interest groups, and ordinary citizens and that this can enrich the decision-making process concerning complex environmental issues such as waste management. We focus our presentation on the results of the application of an informed consensus approach to waste management strategies in the municipality of Sherbrooke (Québec, Canada). KEY WORDS: Informed consensus; Public participation; Decision-making process; Social acceptability; Waste management

Adhesion of Helicobacter pylori to polarized T84 human intestinal cell monolayers is pH dependent.

Epithelial cells, which form tight polarized monolayers on porous substrates, constitute ideal model systems to study bacterial adhesion and invasion. The binding of Helicobacter pylori to the apical membrane of T84 cells, an epithelial cell line derived from a human colon carcinoma, was assessed biochemically and morphologically. Attachment was rapid, and binding remained constant over time, with a significant (P < 0.01, Mann-Whitney U test) ca. fourfold increase at pH 5.4 (76% +/- 22%) compared with pH 7.4 (18% +/- 7%). In contrast, adhesion of enteropathogenic Escherichia coli was not enhanced at pH 5.4. The transepithelial electrical resistance of the T84 cell monolayers was not affected by pH or by H. pylori. Following binding, H. pylori induced a reorganization of the brush border as reflected by actin condensation, facilitating the intimate association of the bacteria with the apical plasma membrane. H.pylori was not internalized, as shown by confocal microscopy. Some bacteria, found in deep invaginations of the apical membrane, were probably inaccessible to gentamicin, thus accounting for the observed tolerance to the antibiotic. These data provide the first evidence that an acidic environment favors Helicobacter adhesion and that binding is followed by survival of the survival of the bacteria in pockets of the apical membrane.

Expansion of the humoral effector cell compartment of both systemic and mucosal immune systems in a weanling murine model which duplicates critical features of human protein-energy malnutrition.

A direct comparison of systemic (spleen) and mucosal (intestine) antibody-producing systems was made in weanling male C57BL/6J mice subjected to wasting protein-energy malnutrition (PEM) by means of a low-protein protocol known to duplicate immunological and physiological features of human malnutrition. ELISA revealed low concentrations of biliary and gut lumen immunoglobulin (Ig) A in malnourished mice concomitantly with a high concentration of blood IgA. The low-protein model, therefore, exhibited fidelity to human protein-energy malnutrition in its influence on the concentrations of the mucosal Ig, IgA, in critical biological fluids. The number of IgA-, IgM- and IgG-containing cells was estimated morphometrically on a per organ basis. The low-protein protocol supported expansion in numbers of mucosal IgA-containing cells (18 x relative to a zero-time control group) and of splenic IgG-containing cells (135x), albeit an attenuated expansion in comparison with that of well-nourished control animals (132x and 571x respectively relative to zero-time controls). Up to terminal differentiation of Ig-containing cells, systemic and mucosal antibody-producing systems exhibited similarly remarkable resistance to wasting malnutrition. Epithelial transport of IgA may be an aspect of the mucosal antibody response which is particularly sensitive to PEM.

Distribution of albumin, alpha 1-inhibitor 3 and their respective mRNAs in periportal and perivenous rat hepatocytes isolated by the digitonin-collagenase technique.

The expression of albumin and alpha 1-inhibitor 3 genes was investigated in rat cell suspensions enriched in periportal (n = 10) and perivenous (n = 10) hepatocytes obtained by the digitonin-collagenase technique. The degree of enrichment of the cell suspensions was assessed: (1) by enzymic assays for the periportal marker alanine aminotransferase and for the perivenous marker glutamine synthetase; and (2) by their content of mRNAs for the periportal marker hepatic glutaminase and for glutamine synthetase. The existence of an antegrade intra-lobular gradient for albumin and alpha 1-inhibitor 3 mRNAs was demonstrated, with periportal:perivenous ratios of 2.33 and 3.80, respectively. However, no gradient was demonstrated for the respective protein contents with corresponding ratios of 0.98 and 1.21. A certain degree of overlap existed between periportal and perivenous suspensions for their content in albumin and alpha 1-inhibitor 3 mRNAs. A morphometrical analysis of the surface of digitonin-permeabilized hepatic tissue revealed that this overlap could be explained by a variable extent of permeabilization of the mediolobular zone from one rat to another and from one lobule to another in a given animal. These results suggest that while the digitonin-collagenase technique is well suited for studies in vitro of proteins expressed in sharp intra-lobular gradients or restricted to an intra-lobular compartment, it is not completely reliable for proteins distributed in continuous moderate intra-lobular gradients, such as albumin and alpha 1-inhibitor 3.

Endothelial cell heterogeneity in the normal human liver acinus: in situ immunohistochemical demonstration.

While a certain degree of structural and functional intra-lobular heterogeneity of sinusoidal endothelial cells has been observed in rodents, little information is available about the zonal characteristics of sinusoidal endothelial cells in the human liver acinus. We have therefore examined the intra-acinar distribution of a panel of endothelial markers in the normal human liver, including: (a) structural markers of continuous and sinusoidal endothelia (PECAM-1, CD-34 protein, VE-cadherin, 1F10 antigen), (b) functional markers specific for sinusoidal endothelial cells, as previously determined in the laboratory (CD4 protein, the lipopolysaccharide-binding protein receptor (CD 14), aminopeptidase N, ICAM-1, receptors II and III for the Fc fragment of immunoglobulins G), (c) endothelial cell-matrix adhesion proteins and leukocyte-endothelial cell adhesion molecules. We observed a heterogeneous distribution for: (a) the 1F10 antigen, whose distribution in the human liver acinus was restricted to vessels situated along the axis of acinar zone 1, (b) the lipopolysaccharide-binding protein receptor and the receptor III for the Fc fragment of IgG, not expressed or only barely expressed in acinar zone 1. The distribution of the other markers tested did not display significant intra-lobular variation. Our in situ results suggest the existence of a degree of zonal heterogeneity in the structural and functional characteristics of sinusoidal endothelial cells in the human liver acinus. This might contribute to the constitution of distinct microenvironments within the human liver parenchyma.

Effects of digitonin on the intracellular content of rat hepatocytes: implications for its use in the study of intralobular heterogeneity.

Anterograde or retrograde perfusion of rat liver with digitonin selectively permeabilizes the periportal or the perivenous zone of the hepatic lobule. Digitonin perfusion is used to analyze the effluents released by permeabilized hepatocytes or, combined with collagenase perfusion, to obtain cell suspensions enriched in either periportal or perivenous hepatocytes. Despite the wide use of digitonin to study lobular heterogeneity, its affects on rat hepatocytes are not well documented. We therefore analyzed the effects of digitonin perfusion on the intracellular content of rat hepatocytes by combining electron microscopy, histoenzymology, immunohistochemistry, and in situ hybridization. At the concentration currently used for the study of lobular heterogeneity, digitonin perfusion induced a marked cytosolic clarification of permeabilized hepatocytes, while most organelles except mitochondria were well preserved. In the digitonin-altered zones, there was no histochemical detection of non-membrane-bound enzymes (lactate dehydrogenase, glutamate dehydrogenase), whereas membrane-bound enzymes (succinate dehydrogenase, beta-hydroxybutyrate dehydrogenase, NADPH dehydrogenase, glucose-6-phosphatase) were still detected. Immunohistochemistry and in situ hybridization revealed significant amounts of several plasma proteins (albumin, alpha 2-macroglobulin, alpha 1-inhibitor 3, alpha 1-acid glycoprotein) and their respective mRNAs in digitonin-permeabilized hepatocytes. The demonstration that digitonin-permeabilized hepatocytes retain many intracellular constituents shows that biochemical analysis of cellular effluents released from digitonin-permeabilized hepatocytes must be interpreted with caution and that the apparent characteristics of cell suspensions obtained by the digitonin-collagenase technique might be significantly altered by contamination with permeabilized hepatocytes from the opposite zone.

Parenchymal innervation of normal and cirrhotic human liver: a light and electron microscopic study using monoclonal antibodies against the neural cell-adhesion molecule.

Hepatic innervation participates in the control of sinusoidal blood flow and in the regulation of certain metabolic functions of the liver. The study of the distribution of hepatic nerves has been hampered by the lack of adequate markers. We therefore tested the value of the neural cell-adhesion molecule (NCAM) as a probe for the study of parenchymal nerves in the normal and cirrhotic human liver. Four antibodies against various epitopes of NCAM were tested by light and electron microscopic immunohistochemistry: Leu19, ERIC-1, VC1.1, and HNK-1. Their reactivity was compared with that of antibodies against the following neural cell markers: S100 protein, neurofilaments, and neuron-specific enolase (NSE). The tissue reactivity of anti-NCAM antibodies was variable, suggesting a microheterogeneity of the NCAM molecule in the normal liver. Clones Leu19 and ERIC-1 proved to be the most sensitive of the anti-NCAM antibodies. Their sensitivity was superior to that of the antibodies directed against the other neural cell markers tested. In the normal liver, both Leu19 and ERIC-1 demonstrated a heterogeneous distribution of nerve fibers inside the hepatic lobule. Intralobular nerve fibers predominated in Zone 1. This might contribute to the constitution of distinct zonal microenvironments inside the hepatic lobule. In cirrhosis, no nerve fiber was detected inside parenchymal nodules; no nerve plexus was visible at the contact of proliferating neoductules. These alterations might contribute to the pathogenesis of the hemodynamic and metabolic disorders observed in cirrhosis.

[Mitchell's osteotomy in the treatment of hallux valgus]. / Ostéotomie de Mitchell dans le traitement de l'hallux valgus.

Ninety-one (91) Mitchell osteotomies on 63 patients (60 females and 3 males) were reviewed. The average follow-up was 40 months (min. 12, max. 70). The average age at the time of the surgery was 51 years (min. 20, max. 74). The presence of a apinful bunion justified the surgery in a majority of cases (92%). The clinical evaluation was done by an independent observer. Weight bearing X-rays of the feet were made in each case. The results show a satisfactory improvement of the pain in 92% of the cases. The patients were satisfied with the appearance of their foot in 93% of the cases. The average active articular range of motion was 47 degrees (min. 20 degrees, max. 120 degrees). The Das De scale showed 75% of excellent and good results. Twelve per cent (12%) of the patients presented residual metatarsalgia. We observed minor complications in 10 cases (11%). We report no cases of avascular necrosis, pseudarthrosis or infection. Clinico-radiological correlations were made. We obtained an average correction of 13 degrees (min. -5 degrees, max. 28 degrees) of the hallux valgus and 3.5 degrees (min. -7 degrees, max. 7 degrees) of the intermetatarsal angle. We recommend the Mitchell osteotomy as long as the indication criterias and the surgical technique are respected.

Functional hepatocellular heterogeneity for the production of plasma proteins.

It is now well established that hepatocytes are the main liver cells responsible for the synthesis of plasma proteins produced by the liver. That these cells are not specialized in the production of the different plasma proteins is also well established. Presently the point still debated is whether a functional hepatocellular heterogeneity exists for plasma protein synthesis as for many other hepatocyte functions. Several physiological and pathological situations suggest that this heterogeneity takes place in the hepatocytes of two opposite hepatic lobular zones, the periportal and centrilobular zones. However, this zonal difference, which supposes different regulatory mechanisms, must be confirmed by techniques other than the now classical immunocytochemistry or the in situ hybridization technique recently proposed for the demonstration of mRNAs in hepatocytes. Another hepatocellular heterogeneity, the intercellular heterogeneity, which can be observed in the same lobular zone, is more difficult to analyze, but shows that from hepatocyte to hepatocyte a variation exists in the synthesis of a given plasma protein.

Transfection of lipoma cells with papilloma bovine virus subgenomic fragment.

Lipoma cells with consistent chromosomal aberration have been transfected with plasmids carrying papilloma bovine virus subgenomic fragment (PBV 69). The successful transformation of the cells was ascerted on the changed growth pattern of the cells in liquid medium, colony formation in soft agar and modified cell appearance in electron microscopy; transfection with PBV 69 has not been, however, sufficient to immortalize lipoma cells.

HIV infection among Quebec women giving birth to live infants.

This is the first anonymous unlinked seroprevalence study in Canada to use serum samples from newborns to determine the seroprevalence rate of human immunodeficiency virus (HIV) infection among childbearing women. Of the 68,808 samples tested 42 were confirmed as positive, for an overall crude seroprevalence rate of 6.1 per 10,000 live births (95% confidence interval [CI] 4.4 to 8.3), or 1 woman in 1638. Women who lived on Montreal island had an overall rate of 17.9 per 10,000 live births (95% CI 12.2 to 25.4), or 1 woman in 559. We observed a significant association between revenue index and seroprevalence; the rates were as high as 46.4 per 10,000 live births (95% CI 18.7 to 95.3), or 1 woman in 216, for Montreal island postal code areas with revenue indexes 20% or more below the provincial median. Extrapolation of the data suggested that 56 women with HIV infection gave birth to a live infant during 1989 in Quebec. Even though attempts to generalize the data from childbearing women to women of childbearing age have an inherent conservative bias, the results of our study suggest that 988 women (95% CI 713 to 1336) aged 15 to 44 years in Quebec had HIV infection in 1989. The actual number is likely substantially higher. The need for well-designed, creative interventions to prevent further HIV transmission to women is evident. Planning for the provision of medical and psychosocial services sensitive to specific needs of women who are already infected should start immediately.

Polarized transport of the polymeric immunoglobulin receptor in transfected rabbit mammary epithelial cells.

A cDNA for the rabbit low Mr polymeric immunoglobulin (poly-Ig) receptor was expressed in an immortalized rabbit mammary cell line. The intracellular routing of the receptor and its cell surface expression was analyzed in stably transfected cells grown on permeable supports. Initially the cells formed a monolayer with no transmural electrical resistance. All monolayer cells expressed the poly-Ig receptor and cytokeratin 7 filaments characteristic of luminal mammary cells but absent in myoepithelial cells. Within 7 d in culture, the cells underwent cytodifferentiation and formed a bilayer with a transepithelial electrical resistance of approximately 500 omega x cm2. Upper layer cells formed tight junctions with adjacent cells and gap junctions with basal cells. Expression of the poly-Ig receptor and cytokeratin 7 was restricted to the cells from the upper layer. The kinetics of receptor biosynthesis and processing was similar to that reported for rabbit mammary gland and rat liver. The receptor was cleaved at the apical cell surface and release of secretory component into the apical medium occurred with a half-time of approximately 2 h. Selective cell surface trypsinization combined with pulse-chase experiments served to determine at which cell surface domain newly synthesized receptor appeared first. The receptor was digested with a half-time of approximately 60 min with trypsin present in the basolateral medium and 90 min with apical trypsin. These data are consistent with selective targeting of newly synthesized receptor to the basolateral surface. The results indicate that transcytosis of the receptor from basolateral to apical membrane in the presence or the absence of its ligand requires approximately 30 min. Cleavage of the receptor by endogenous protease is not concomitant with its appearance at the apical surface, but requires additional time, thus explaining the presence of intact receptor on the apical membrane.

Processing of the polymeric immunoglobulin receptor.

The transcellular transport of polymeric immunoglobulins (pIg) across mucosal epithelia is mediated by a membrane glycoprotein known as the polymeric immunoglobulin receptor (pIgR). The intracellular routing of the pIgR has been used as a model to study protein traffic. Examination of the biosynthesis and processing of the pIgR in mammary gland and liver have led to a working hypothesis for pIgR routing in the cell. These hypotheses are currently being tested in an immortalized cell line derived from rabbit mammary gland alveolar cells.

Distribution and processing of the polymeric immunoglobulin receptor in the rat hepatocyte: morphological and biochemical characterization of subcellular fractions.

The transepithelial transport of polymeric immunoglobulins is an essential process in the mucosal immune system. Transport across the epithelial cells of mucous or exocrine glands is affected by an integral membrane glycoprotein receptor known as membrane secretory component (SCm) or as polymeric immunoglobulin receptor (pIgR). This receptor binds polymeric immunoglobulins at the basolateral cell surface and mediates their transcellular translocation and their release from the apical plasma membrane into external secretions. Release depends on cleavage of the membrane-anchoring domain of the receptor, resulting in liberation of polymeric immunoglobulin bound to the ectoplasmic domain of the receptor (secreted SC or SCs) into extracellular secretions. Using a monoclonal antibody directed against the cytoplasmic tail of the receptor and a polyclonal antibody directed against the secreted ectoplasmic domain, we have combined cell fractionation and Western blotting techniques to examine the fate of these receptor domains in the hepatocyte. In this study, we characterize biochemically and morphologically the various subcellular components separated by our fractionation scheme, and correlate this with biochemical analysis of the receptor in each fraction.

Effect of cell shape change on the function and differentiation of rabbit mammary cells in culture.

We examined the role of cell shape, cytodifferentiation, and tissue topography on the induction and maintenance of functional differentiation in rabbit mammary cells grown as primary cultures on two-dimensional collagen surfaces or in three-dimensional collagen matrices. Mammary glands from mid-pregnant rabbits were dissociated into single cells, and epithelial cells were enriched by isopycnic centrifugation. Small spheroids of epithelial cells (approximately 50 cells) that formed on a rotary shaker were plated on or embedded in collagen gels. The cells were cultured for 1 d in serum-containing medium and then for up to 25 d in chemically defined medium. In some experiments, epithelial monolayers on gels were mechanically freed from the dishes on day 2 or 5. These gels retracted and formed floating collagen gels. On attached collagen gels, flat monolayers of a single cell type developed within a few days. The cells synthesized DNA until the achievement of confluence but did not accumulate milk proteins. No morphological changes were induced by prolactin (PRL). On floating gels, two cell types appeared in the absence of cell proliferation. The cells in direct contact with the medium became cuboidal and developed intracellular organelles typical of secretory cells. PRL-induced lipogenesis, resulting in large fat droplets filling the apical cytoplasm and accumulation of casein and alpha-lactalbumin in vesicles surrounding the fat droplets. We detected tranferrin in the presence or absence of PRL intracellularly in small vesicles but also in the collagen matrix in contact with the cell layer. The second cell type, rich in microfilaments and reminiscent of the myoepithelial cells, was situated between the secretory cell layer and the collagen matrix. In embedding gels, the cells formed hollow ductlike structures, which grew continuously in size. Secretory cells formed typical lumina distended by secretory products. We found few microfilament-rich cells in contact with the collagen gels. Storage and secretion of fat, caseins and alpha-lactalbumin required the presence of PRL, whereas the accumulation and vectorial discharge of transferrin was prolactin independent. There was no differentiation gradient between the tip and the cent of the outgrowth, since DNA synthesis and milk protein storage were random along the tubular structures. These results indicate that establishment of functional polarity and induction of cytodifferentiation are influenced by the nature of the interaction of the cells with the collagen structure. The morphological differentiation in turn plays an important role in the synthesis, storage, and secretion of fat and milk proteins.

Attempts to quantitate immunocytochemistry at the electron microscope level.

The ability to localize intracellular macromolecules in situ by high resolution techniques has been made possible by the development of antibody labelling of thin sections obtained either from tissues embedded in an hydrophilic matrix, or by ultracryotomy or from conventional plastic embedded tissue. When particle-tagged immunological reagents are used to visualize intracellular antigens, quantitative information can be obtained by combining particle counts with morphometric estimations of compartment volume. Various detection systems have been used successfully for quantitation, which include ferritin-conjugated antibodies, biotin-avidin-ferritin complexes and, more recently, gold-protein A conjugates. Examples of the use of these techniques the localization of secretory proteins in pancreatic exocrine cells, opsin and a large membrane protein in photoreceptor cells of frog retina, and contractile proteins in skeletal muscle are given. Quantitative data obtained by morphometric analysis, both in bovine and rat pancreatic exocrine cells, are compared with values assessed by biochemical methods.