Enrichment of the R77C alpha-sarcoglycan gene mutation in Finnish LGMD2D patients.

Limb-girdle muscular dystrophy 2D (LGMD2D) is caused by mutations in the alpha-sarcoglycan gene (SGCA). The most frequently reported mutation, 229CGC>TGC (R77C) in exon 3 of SGCA, results in the substitution of arginine by cysteine. We present here the clinical, immunohistochemical, and genetic data of 11 Finnish patients with LGMD2D caused by mutations in SGCA. Mutational analysis showed 10 patients homozygous and 1 compound heterozygous for R77C. A wide spectrum of SGCA mutations has been reported previously. Our results show an enrichment of R77C in Finland, further underlined by the observed carrier frequency of 1 per 150. According to the annual birth rate of approximately 60,000 in Finland, one LGMD2D patient with a homozygous mutation is expected to be born every 1 or 2 years on average. The presence of an ancient founder mutation is indicated by the fact that all patients shared a short common haplotype extending > or = 790 kilobases. Our results emphasize the need to include the SGCA gene R77C mutation test in routine DNA analyses of severe dystrophinopathy-like muscular dystrophies in Finland, and suggest that the applicability of this test in other populations should be studied as well.

Reconstruction with rectus abdominis myocutaneous free flap after orbital exenteration in children.

OBJECTIVE: To present a 1-stage technique for orbital reconstruction after exenteration with the use of myocutaneous rectus abdominis free flap in children. SURGICAL TECHNIQUE: After orbital exenteration, a myocutaneous rectus abdominis free flap with long vascular pedicle is harvested from the abdomen. The flap is transferred to the orbit and the vascular pedicle is passed through an opening made in the lateral orbital wall, where it is anastomosed to superficial temporal vessels. The skin of the flap is trimmed to correspond to the eyelid defect and the incisions are closed. METHODS: After informed consent was obtained, 2 children, 3 and 8 years old, underwent orbital reconstruction with a rectus abdominis free flap after exenteration for orbital rhabdomyosarcoma and orbital osteosarcoma in the setting of retinoblastoma. RESULTS: This technique allowed easy postoperative wound care. Viability of the flap was excellent. The technique provided sufficient volume to fill the orbit, with improved aesthetic results and minimal donor site deformity. CONCLUSIONS: The postoperative care and aesthetic outcome in patients with rectus abdominis free flap after exenteration are much improved over those provided with traditional surgical techniques. This primary reconstruction is recommended for any patient requiring orbital exenteration, but particularly for pediatric patients who tolerate debridement of traditional exenteration sites poorly.

Evaluation of chemoprophylaxis in patients with unilateral retinoblastoma with high-risk features on histopathologic examination.

OBJECTIVES: To identify risk factors for metastatic disease on histopathologic specimens of enucleated eyes from patients with unilateral retinoblastoma, and to evaluate the value of chemoprophylaxis in preventing disease dissemination. METHODS: Medical records from patients with unilateral retinoblastoma who underwent primary enucleation were reviewed at the University of California, San Francisco (1977-1998) and Bascom Palmer Eye Institute, University of Miami, Miami, Fla (1991-1998). All routine histopathologic specimens were reexamined. The extent of tumor invasion into the optic nerve or ocular coats and the prescribed chemoprophylactic regimen were recorded. RESULTS: This retrospective study included 129 patients followed for a median of 54 months. Three patients had tumor invading the sclera. The optic nerve was involved to some extent in 82 patients, 11 of whom had tumor extension beyond the lamina cribrosa. The surgical margin of the optic nerve was involved in an additional 4 patients. The choroid was involved in 43 patients, and was considered massively affected in 12 patients. Anterior segment involvement was observed in 10 patients. Postenucleation chemoprophylaxis was administered to 4 of 4 patients who had tumor cells at the surgical margin of the optic nerve and to 7 of 11 patients with postlaminar disease, all of whom had at least 1 mm of postlaminar tumor extension. External beam radiotherapy was administered to 3/4 and 1/11 of these patients, respectively. Chemoprophylaxis was not administered to patients with choroidal or anterior chamber involvement unless the optic nerve was also involved beyond the lamina cribrosa. One patient with tumor extending to the surgical margin of the optic nerve died of metastatic disease. CONCLUSIONS: Chemoprophylaxis is necessary for patients with tumor extending to the surgical margin of the optic nerve and is likely to be beneficial in preventing metastases in patients with tumor extending beyond the lamina cribrosa. We did not offer chemoprophylaxis to patients with prelaminar optic nerve disease or isolated choroidal involvement, and these patients remained free of disseminated disease.

The HNK-1 carbohydrate epitope in the eye: basic science and functional implications.

The HNK-1 carbohydrate epitope is part of many cell membrane and extracellular matrix molecules. It has been implicated in cell to cell and cell to extracellular matrix adhesion, and antibodies to the HNK-1 epitope are emerging as a versatile tool in eye research. They have been used to identify a novel cell type in the human eye, the subepithelial matrix cells that reside in the inner connective tissue layer (ICTL) of the ciliary body. Although these cells resemble fibroblasts in ultrastructure, they form a distinct cell population that differs in its antigenic profile from fibroblasts of other tissues. These cells are associated with the elastic fiber system of the ICTL. Other structures in the human eye that harbor the HNK-1 epitope in a nonrandom pattern are the ciliary and iris epithelia, the zonular lamella, the lens capsule, the retina, glial cells of the optic and ciliary nerves, and scleral fibroblasts. The HNK-1 epitope in the eye appears early during embryonic development and is phylogenetically conserved, but many interspecies differences exist in its distribution. The role of the HNK-1 epitope may be to structurally stabilize the ciliary body and the retina, and to participate in zonular attachments. The HNK-1 epitope has been linked with many common eye diseases. The subepithelial matrix cells seem to be susceptible to undergo irreversible damage as a result of glaucoma, thermal injury, and tissue compression. This epitope has proved to be useful in identifying intraocular deposits of exfoliation syndrome. It can explain the adhesiveness of exfoliation material. Intraocular exfoliation material differs in HNK-1 immunoreactivity from the extraocular fibrillopathy of exfoliation syndrome and its presence in fellow eyes also argues against the concept of unilateral exfoliation syndrome. The HNK-1 epitope is found in the extracellular matrix of secondary cataract and anterior subcapsular cataract, and it may contribute to their pathogenesis. Finally, the HNK-1 epitope can be used to trace neuroepithelial derivatives of the optic vesicle in developmental anomalies and in tumors of the eye. Eventual identification of molecules that bear the HNK-1 epitope in the eye will likely shed light on many aspects of ocular physiology and pathobiology

A road to kidney tubules via the Wnt pathway.

Classical in vitro studies indicate that tubule induction in the kidney mesenchyme is mediated by cell-cell contacts between the inducer tissue and the metanephric mesenchyme. Induction is completed within the first 24 h, after which tubules will form because of stimulated cell proliferation, migration, and cell adhesion. Recent evidence has revealed an essential role for the secreted signals from the Wnt gene family. Of these, Wnt-4 is expressed in developing tubules and knocking out its function perturbed kidney development. More detailed studies demonstrated normal condensation, but tubules were missing. Subsequent experiments indicated that Wnt-4 is also a sufficient signal to trigger tubulogenesis. Cells that were engineered to express Wnt-4 not only induced tubulogenesis in the kidney mesenchyme of Wnt-4 mutant embryos, but also induced tubules in the wild type mesenchyme. With the transfilter induction assay, Wnt-4-mediated induction was completed within the first 24 h, depending on the presence of proteoglycans and cell-cell contacts between the interactants. In addition, Wnt-4 autoinduced expression of its own gene and a panel of other components of the Wnt signalling pathway, such as frizzleds and a candidate Wnt antagonist from the secreted frizzled-related protein family. Taken together, the data provide evidence of an essential role for Wnt signal transmission and transduction pathways in the induction of kidney tubules, and the findings have paved the way for detailed molecular studies.

Search for autoantibodies against the HNK-1 carbohydrate epitope in the human eye in intermediate uveitis.

PURPOSE: Molecules bearing the immunogenic HNK-1 epitope are present in the inner connective tissue layer and epithelia of the ciliary body. We investigated whether autoantibodies to these molecules can be detected in patients with intermediate uveitis, which affects the ciliary body. METHODS: Serum was collected from 9 patients with intermediate uveitis, and from 6 controls with idiopathic iritis and 3 controls with sarcoid uveitis, representing nongranulomatous and granulomatous uveitis, respectively. The sera were used as polyclonal antibodies to immunostain 3 formalin-fixed, paraffin-embedded normal human donor eyes by the avidin-biotinylated peroxidase complex method. RESULTS: No immunostaining in the ciliary body could be detected using the sera from patients with intermediate uveitis or from the controls. Serum within blood vessels was nonspecifically immunolabelled with the secondary anti-human anti-serum. CONCLUSION: No autoantibodies against the HNK-1 epitope or other antigens of the ciliary body could be demonstrated in patients with intermediate uveitis. It is unlikely that such autoantibodies against the HNK-1 epitope have a role in intermediate uveitis.

Immunolocalization of transforming growth factor-beta1 and tenascin in human secondary cataract.

PURPOSE: This study was carried out to investigate the distribution of transforming growth factor-beta1 (TGF-beta1) and the extracellular matrix (ECM) glycoprotein tenascin in secondary cataract and anterior subcapsular cataract. METHODS: Twenty-four pseudophakic human eyes with secondary cataract, obtained at autopsy 1 d to 10 yr (mean 2.4 yr) after cataract surgery, were studied. Additionally, a specimen from an anterior subcapsular cataract was included. Immunohistochemistry was used to localize TGF-beta1 and tenascin in secondary cataract and in anterior subcapsular cataract. RESULTS: Polyclonal antibody to TGF-beta1 immunolabelled spindle-shaped cells in the plaques of secondary cataract in all eyes. Instead, the cells present in Soemmering's ring cataract were not labelled. The ECM in the plaques of secondary cataract was immunoreactive for tenascin in all eyes. In anterior subcapsular cataract spindle-shaped cells and ECM showed similar immunoreactivity. CONCLUSION: Spindle-shaped cells that are immunolabelled with TGF-beta1 and ECM showing tenascin-like-immunoreactivity are present in secondary cataract and in anterior subcapsular cataract, thus implicating a possible role in secondary cataract.

Wnts as kidney tubule inducing factors.

Since the discovery that inductive tissue interactions regulate nephrogenesis, one of the aims has been to identify the molecules that mediate this induction. The small size of embryonic tissue has limited the possibilities to identify the inducers biochemically, even though such efforts were directed to study, e.g. neural induction (for a comprehensive review, Saxén and Toivonen, Primary embryonic induction, Academic Press, London, 1962). The rapid progress in molecular biology made it possible to identify genes from minute amounts of tissue and provided techniques to generate recombinant proteins to assay their action in classic experimental systems. This led to the identification of some signals that are involved in primary and secondary inductive interactions during embryogenesis. Here, we will review evidence suggesting that secreted signaling molecules from the Wnt gene family mediate kidney tubule induction.

Electron spin resonance (ESR) probe for interventional MRI instrument localization.

This article presents a miniaturized electron spin resonance (ESR) probe for deducing the position of a surgical instrument on an MR image. The ESR probe constructed was small enough to fit inside a 14-G biopsy needle sheath, and position information of the sheath could be acquired using a simple gradient sequence. The position accuracy was estimated from needle trajectories as inferred from the needle artifact, the actual physical trajectory, and measured coordinates. The probe was able to track the tip of a biopsy needle quickly (10 samples/sec) and precisely with accuracy better than +/-2 mm. J. Magn. Reson. Imaging 1999;10:216-219.

Small airway obliteration in a new swine heterotopic lung and bronchial allograft model.

BACKGROUND: We studied a heterotopic large-animal model with obliterative airway lesions caused by allograft rejection. METHODS: Lung fragments (1 cm3) with airways (LB), and 1 to 2 mm diameter bronchi alone (B) were implanted subcutaneously in 11 domestic piglets weighing 20 kg. Six animals each received 40 implants from nonrelated donors without immunosuppression (group A). Another 5 animals had autograft implants (group U). The implants were harvested consecutively for histologic analysis over 3 months in group A and 6 months in group U. RESULTS: In group U, the initial ischemia caused mild to moderate epithelial damage with moderate metaplasia but with a return to normal ciliary epithelium within 1 month. Transient mild luminal obliteration with granulation tissue and mononuclear cells was observed during the first weeks, but after 4 weeks the lumen was patent and filled with mucus. In the bronchial wall, moderate fibrosis developed in LB implants, whereas mild fibrosis was seen in B implants. In group A, the epithelium was totally absent by 2 weeks, and mild inflammation, fibrosis, and destruction of the cartilage with pericartilaginous mononuclear accumulation were observed in the bronchial wall. Small airways were gradually obliterated between days 7 and 21, initially by granulation tissue and mononuclear cells and later by progressive fibrosis. CONCLUSIONS: In this model, autografted airway implants stayed patent for at least 6 months, whereas total luminal obliteration histologically resembling obliterative bronchiolitis developed in allografts within 21 days. Because small airways, including bronchioli, can be transplanted with the use of this model, it may be useful for research into the causes of airway obliteration, which may be relevant to the pathogenesis of obliterative bronchiolitis in lung recipients.

Structure, development and function of cytoskeletal elements in non-neuronal cells of the human eye.

The cytoskeleton, of which the main components in the human eye are actin microfilaments, intermediate filaments and microtubules with their associated proteins, is essential for the normal growth, maturation, differentiation, integrity and function of its cells. These components interact with intra- and extracellular environment and each other, and their profile frequently changes during development, according to physiologic demands, and in various diseases. The ocular cytoskeleton is unique in many ways. A special pair of cytokeratins, CK 3 and 12, has apparently evolved only for the purposes of the corneal epithelium. However, other cytokeratins such as CK 4, 5, 14, and 19 are also important for the normal ocular surface epithelia, and other types may be acquired in keratinizing diseases. The intraocular tissues, which have a relatively simple cytoskeleton consisting mainly of vimentin and simple epithelial CK 8 and 18, differ in many details from extraocular ones. The iris and lens epithelium characteristically lack cytokeratins in adults, and the intraocular muscles all have a cytoskeletal profile of their own. The dilator of the iris contains vimentin, desmin and cytokeratins, being an example of triple intermediate filament expression, but the ciliary muscle lacks cytokeratin and the sphincter of the iris is devoid even of vimentin. Conversion from extraocular-type cytoskeletal profile occurs during fetal life. It seems that posttranslational modification of cytokeratins in the eye may also differ from that of extraocular tissues. So far, it has not been possible to reconcile the cytoskeletal profile of intraocular tissues with their specific functional demands, but many theories have been put forward. Systematic search for cytoskeletal elements has also revealed novel cell populations in the human eye. These include transitional cells of the cornea that may represent stem cells on migration, myofibroblasts of the scleral spur and juxtacanalicular tissue that may modulate aqueous outflow, and subepithelial matrix cells of the ciliary body and myofibroblasts of the choroid that may both participate in accommodation. In contrast to the structure and development of the ocular cytoskeleton, changes that take place in ocular disease have not been analysed systematically. Nevertheless, potentially meaningful changes have already been observed in corneal dystrophies (Meesmann's dystrophy, posterior polymorphous dystrophy and iridocorneal endothelial syndrome), degenerations (pterygium) and inflammatory diseases (Pseudomonas keratitis), in opacification of the lens (anterior subcapsular and secondary cataract), in diseases characterized by proliferation of the retinal pigment epithelium (macular degeneration and proliferative vitreoretinopathy), and in intraocular tumours (uveal melanoma). In particular, upregulation of alpha-smooth muscle actin seems to be a relatively general response typical of spreading and migrating corneal stromal and lens epithelial cells, trabecular cells and retinal pigment epithelial cells.

Cell types of secondary cataract: an immunohistochemical analysis with antibodies to cytoskeletal elements and macrophages.

BACKGROUND: The study was carried out to identify cell types of secondary cataract after extracapsular cataract extraction and implantation of an intraocular lens. METHODS: Twenty-five formalin-fixed, paraffin-embedded pseudophakic human eyes with secondary cataract, obtained at autopsy, were studied and compared to a specimen from an anterior subcapsular cataract with a panel of six monoclonal antibodies (MAbs, to vimentin, cytokeratin (CK) 8 and 18, desmin, alpha-smooth muscle actin, and the CD68 epitope of macrophages by the avidin-biotinylated peroxidase complex (ABC) method. RESULTS: MAb Vim 3B4 to vimentin immunolabeled spindle-shaped cells in 16 of 17 central plaques of secondary cataract as well as cells in all 16 Soemmering's ring cataracts. Spindle-shaped cells reacted with MAb CAM 5.2 to CK 8 in 13 of 18 eyes, but only one specimen was labeled with MAb CY-90 to CK 18. No immunoreaction was seen with MAb D33 to desmin, whereas MAb 1A4 to alpha-smooth muscle actin immunolabeled spindle-shaped cells in 15 of 18 plaques of secondary cataract. Macrophages were seen with MAb PG-M1 in 13 of 19 secondary cataracts. In the anterior subcapsular cataract, spindle-shaped cells under a wrinkled but otherwise intact capsule reacted with MAb Vim 3B4 to vimentin, MAb CAM 5.2 to CK 8, and MAb 1A4 to alpha-smooth muscle actin. CONCLUSION: Spindle-shaped cells in secondary and anterior subcapsular cataracts react with antibodies to vimentin, CK 8 and alpha-smooth muscle actin, suggesting them to be metaplastic epithelial cells that derive from the lens epithelium. alpha-Smooth muscle actin persists in them at least 10 years postoperatively, but CK 8 starts to disappear after 3 years. Macrophages are one possible modulator of this transdifferentiation.

Visual motion activates V5 in dyslexics.

A recent functional magnetic resonance imaging (fMRI) study concluded that the motion-specific visual area V5 is not activated in dyslexic subjects. We report here opposing evidence based on whole-scalp neuromagnetic recordings. Apparent-motion stimuli elicited similar activation of V5 in both dyslexic and control subjects, with a trend for longer latencies in dyslexics. Both high- and low-contrast stimuli activated the V5 region in dyslexics. The lack of significant blood flow changes despite modified neuronal synchrony would explain the absence of fMRI signals and the presence of neuromagnetic signals in dyslexic subjects.

Detection of acute rejection by 133Xe radiospirometry after single lung transplantation in an experimental porcine model.

Aim of this experimental study was to evaluate acute rejection in a porcine single-lung transplantation model by using 133Xe radiospirometry. Left lung allotransplantation was performed on 11 and autotransplantation on 5 piglets. Postoperative monitoring consisted of 77 radiospirometric examinations with assessments of regional perfusion (Qtx), ventilation (V) and ventilation/perfusion ratio (V/Qtx). Results were compared with transbronchial biopsy. A significant decrease in Qtx (p < 0.01) and an increase in V/Qtx (p < 0.01) were observed during acute rejection, whereas V remained unaltered. These changes were significant already at minimal rejection (grade A1), and further increased at moderate rejection (grade A3). Sensitivity and specificity of Qtx were 82 and 74%, and those of V/Qtx, 87 and 65%. 133Xe radiospirometry detects even minimal acute rejection after single lung transplantation.

Acute rejection diagnosed with computed tomography in a porcine experimental lung transplantation model.

The role of computed tomography (CT) in the diagnosis of acute rejection was studied in an experimental lung transplantation model, with 15 left lung allotransplantations and six autotransplantations performed on piglets weighing 16-24 kg. There were 31 episodes of acute rejection. In the allotransplantation group the development of acute rejection was monitored 115 times with CT, transbronchial biopsy (TBB) and bronchoalveolar lavage (BAL). The stages of acute rejection were 1) ill-defined centrilobular micronodules or minimal patchy ground-glass opacities. 2) dense, small-nodular infiltration or extensive ground-glass opacities, and bronchial wall thickening. 3) lung volume loss and dense, patchy ground-glass opacities and 4) consolidation of the lung. In the autotransplantation group monitoring was done 42 times. After allotransplantation, TBB and BAL suggested rejection 60 times and infection 23 times. CT had 86.7% sensitivity and 85.6% specificity. During the first month these figures were, respectively, 71.4% and 84.2%. Rising histologic grade was associated with increasing stage of acute rejection on CT, which thus proved to be a sensitive and specific method for diagnosing acute rejection of lung transplant.

The HNK-1 epitope in the pseudophakic and aphakic eye and secondary cataract.

PURPOSE: To search for changes in the presence and distribution of the cell-adhesion-related HNK-1 carbohydrate epitope after cataract extraction. METHODS: Twenty-five pseudophakic and two aphakic human autopsy eyes and, for comparison, one anterior subcapsular cataract obtained at surgery were studied with monoclonal antibodies (MAbs) HNK-1 and NC-1 to the HNK-1 epitope using the avidin-biotinylated peroxidase complex method. RESULTS: MAbs to the HNK-1 epitope constantly immunolabelled the inner connective tissue layer of the ciliary body in all pseudophakic and aphakic eyes studied. The distribution of the immunoreaction was similar to that reported for normal eyes. They also labelled the extracellular matrix in each of 18 plaques of secondary cataract on the posterior capsule, in each of 13 plaques at the rim of the capsular bag, and in the anterior subcapsular cataract. Bladder cells in each of 16 Soemmering's rings remained unlabelled. CONCLUSION: The distribution of the HNK-1 epitope in the ciliary body does not appreciably change after cataract extraction, although the accommodative demand of the eye is altered. Its presence in an anterior subcapsular cataract suggests that the epitope may be locally produced by lens epithelial cells also in secondary cataract. The epitope is associated with cell adhesion and migration, both of which may play a role in the pathogenesis of secondary cataract.

Lectin and immunohistochemical comparison of glycoconjugates in the conjunctiva of patients with and without exfoliation syndrome.

AIMS--The study was carried out to search for labelling similar to that of intraocular exfoliation material in the conjunctiva by light microscopy using lectin and immunohistochemistry. METHODS--Ten formalin fixed and paraffin embedded conjunctival biopsy specimens both from patients with and without exfoliation syndrome were studied with a panel of 11 lectins and with three monoclonal antibodies to the HNK-1 carbohydrate epitope, all of which react with intraocular exfoliation material. RESULTS--The lectin binding profile was essentially the same in specimens from patients with and without exfoliation syndrome. The superficial epithelium reacted similarly with Phaseolus vulgaris (PHA-E), Caragana arborescens (CAA), Helix pomatia (HPA), concanavalin A (ConA), and wheat germ (WGA) agglutinins. Binding was also detected with peanut (PNA) and Bauhinia purpurea (BPA) agglutinins, particularly in patients with exfoliation. The basement membrane generally reacted with Ricinus communis (RCA-I), PHA-E, Vicia villosa (VVA), ConA, and Lens culinaris (LCA) agglutinins. The stroma was weakly labelled with RCA-I, PHA-E, ConA, and LCA. Lectin binding to the vascular endothelium was moderate with RCA-I, PHA-E, CAA, ConA, LCA, and WGA. Inconsistent labelling was also detected with PNA, BPA, and Erythrina cristagalli agglutinin (ECA). The subendothelial region reacted weakly but consistently with PHA-E, ConA, and LCA, and inconsistently with PNA. Pretreatment with neuraminidase did not change that pattern. Antibodies to the HNK-1 epitope reacted only with myelinated stromal nerve branches. CONCLUSION--No evidence of abnormal deposits in any specimen was found. The carbohydrate composition of intraocular exfoliation material may differ from that of exfoliation-like fibres often detected in the conjunctiva by electron microscopy.

Immunohistochemical localization of chondroitin sulfate proteoglycan and tenascin in the human eye compared with the HNK-1 epitope.

BACKGROUND: A previous study revealed the HNK-1 epitope in the human ciliary body beneath the ciliary epithelium. The molecules bearing this 3-sulphoglucuronic acid-containing oligosaccharide epitope in the eye remain unknown. As chondroitin sulphate proteoglycan (CSPG) and tenascin are potential candidates as bearers of the HNK-1 epitope, their distribution in the human eye was compared with that of the HNK-1 epitope. METHODS: Fifty-five formalin-fixed, paraffin-embedded human eyes, including 20 normal eyes and 35 eyes with exfoliation syndrome or glaucoma, were studied immunohistochemically with monoclonal antibody (MAb) CS-56 to CSPG, MAb TN2 to tenascin, and MAbs HNK-1 and VC1.1 to the HNK-1 epitope. Additionally, four frozen lens capsules with exfoliation material were studied by indirect immunofluorescence. RESULTS: A population of dendritic cells in the inner connective tissue layer of the ciliary body and exfoliation material were immunoreactive with antibodies to the HNK-1 epitope, but no labelling for CSPG and tenascin was seen in them, including frozen sections. The inner surface of the nonpigmented ciliary epithelium was reactive for the HNK-1 epitope, and at the ora serrata also for CSPG. In some eyes with glaucoma, immunoreaction for CSPG and tenascin was seen beneath the epithelium and endothelium of the cornea. The nerve fibre layer of the retina was labelled for tenascin. In the sclera, all antibodies labelled the ground substance, and in some large blood vessels immunoreaction for CSPG and tenascin was seen subendothelially. CONCLUSION: Apart from the sclera, the distribution of CSPG and tenascin was different form that of the HNK-1 epitope, suggesting that this carbohydrate epitope may not be borne by these molecules in the human ciliary body.