Unguarded Tricuspid Valve and Pulmonary Atresia With Intact Ventricular Septum Complicated With Right Coronary Artery Fistula and Advanced Atrioventricular Block in a Fetus: A Case Report

The unguarded tricuspid valve is a rare and severe condition. When found in the fetus, they mostly undergo abortion or intrauterine death. The details of the fetal course in such cases are poorly understood. Here, we report a case of an unguarded tricuspid valve detected at 20 weeks of gestation who developed a complete atrioventricular block and survived in utero. The fetus also had pulmonary atresia with intact ventricular septum, Uhl's disease, hypoplastic right ventricle, noncompacted left ventricle, valvular aortic stenosis, and right coronary artery fistula to the right ventricle. Despite this serious condition, the fetal hydrops did not develop. The baby was born at 33 weeks of gestation but died on day two. Our experience suggests that some babies may survive the fetal period even with the severe type of an unguarded tricuspid valve. Hence, efficient fetal and neonatal treatment strategies for fetal unguarded tricuspid valves are crucial.

A novel LSD1 inhibitor NCD38 ameliorates MDS-related leukemia with complex karyotype by attenuating leukemia programs via activating super-enhancers

Lysine-specific demethylase 1 (LSD1) regulates gene expression by affecting histone modifications and is a promising target for acute myeloid leukemia (AML) with specific genetic abnormalities. Novel LSD1 inhibitors, NCD25 and NCD38, inhibited growth of MLL-AF9 leukemia as well as erythroleukemia, megakaryoblastic leukemia and myelodysplastic syndromes (MDSs) overt leukemia cells in the concentration range that normal hematopoiesis was spared. NCD25 and NCD38 invoked the myeloid development programs, hindered the MDS and AML oncogenic programs, and commonly upregulated 62 genes in several leukemia cells. NCD38 elevated H3K27ac level on enhancers of these LSD1 signature genes and newly activated ~500 super-enhancers. Upregulated genes with super-enhancer activation in erythroleukemia cells were enriched in leukocyte differentiation. Eleven genes including GFI1 and ERG, but not CEBPA, were identified as the LSD1 signature with super-enhancer activation. Super-enhancers of these genes were activated prior to induction of the transcripts and myeloid differentiation. Depletion of GFI1 attenuated myeloid differentiation by NCD38. Finally, a single administration of NCD38 causes the in vivo eradication of primary MDS-related leukemia cells with a complex karyotype. Together, NCD38 derepresses super-enhancers of hematopoietic regulators that are silenced abnormally by LSD1, attenuates leukemogenic programs and consequently exerts anti-leukemic effect against MDS-related leukemia with adverse outcome.

Fgfr2 is integral for bladder mesenchyme patterning and function

While urothelial signals, including sonic hedgehog (Shh), drive bladder mesenchyme differentiation, it is unclear which pathways within the mesenchyme are critical for its development. Studies have shown that fibroblast growth factor receptor 2 (Fgfr2) is necessary for kidney and ureter mesenchymal development. Our objective was to determine the role of Fgfr2 in bladder mesenchyme. We used Tbx18cre mice to delete Fgfr2 in bladder mesenchyme (Fgfr2^BM-/-). We performed three-dimensional reconstructions, quantitative real-time PCR, in situ hybridization, immunolabeling, ELISAs, immunoblotting, void stain on paper, ex vivo bladder sheet assays, and in vivo decerebrated cystometry. Compared with controls, embryonic (E) day 16.5 (E16.5) Fgfr2^BM-/- bladders have thin muscle layers with reduced α-smooth muscle actin levels and thickened lamina propria with increased collagen expression that intrudes into muscle. From postnatal (P) day 1 (P1) to P30, Fgfr2^BM-/- bladders demonstrate progressive muscle loss and increased collagen expression. Postnatal Fgfr2^BM-/- bladder sheets exhibit decreased contractility and increased passive stretch tension compared with controls. In vivo cystometry revealed high baseline and threshold pressures and shortened intercontractile intervals in Fgfr2^BM-/- bladders compared with controls. Mechanistically, while Shh expression appears normal, mRNA and protein readouts of hedgehog activity are increased in E16.5 Fgfr2^BM-/- bladders compared with controls. Moreover, E16.5Fgfr2^BM-/- bladders exhibit higher levels of Cdo and Boc, hedgehog coreceptors that enhance sensitivity to Shh, than controls. Fgfr2 is critical for bladder mesenchyme patterning by virtue of its role in modulation of hedgehog signaling.

Fgfr2 is integral for bladder mesenchyme patterning and function

While urothelial signals, including sonic hedgehog (Shh), drive bladder mesenchyme differentiation, it is unclear which pathways within the mesenchyme are critical for its development. Studies have shown that fibroblast growth factor receptor (Fgfr)2 is necessary for kidney and ureter mesenchymal development. The objective of the present study was to determine the role of Fgfr2 in the bladder mesenchyme. We used Tbx18cre mice to delete Fgfr2 in the bladder mesenchyme (Fgfr2(BM-/-)). We performed three-dimensional reconstructions, quantitative real-time PCR, in situ hybridization, immunolabeling, ELISAs, immunoblot analysis, void stain on paper, ex vivo bladder sheet assays, and in vivo decerebrated cystometry. Compared with control bladders, embryonic day 16.5 (E16.5) Fgfr2(BM-/-) bladders had thin muscle layers with less α-smooth muscle actin and thickened lamina propria with increased collagen type Ia and IIIa that intruded into the muscle. The reciprocal changes in mutant layer thicknesses appeared partly due to a cell fate switch. From postnatal days 1 to 30, Fgfr2(BM-/-) bladders demonstrated progressive muscle loss and increased collagen expression. Postnatal Fgfr2(BM-/-) bladder sheets exhibited decreased agonist-mediated contractility and increased passive stretch tension versus control bladder sheets. Cystometry revealed high baseline and threshold pressures and shortened intercontractile intervals in Fgfr2(BM-/-) versus control bladders. Mechanistically, whereas Shh expression appeared normal, mRNA and protein readouts of hedgehog activity were increased in E16.5 Fgfr2(BM-/-) versus control bladders. Moreover, E16.5 Fgfr2(BM-/-) bladders exhibited higher levels of Cdo and Boc, hedgehog coreceptors that enhance sensitivity to Shh, compared with control bladders. In conclusion, loss of Fgfr2 in the bladder mesenchyme leads to abnormal bladder morphology and decreased compliance and contractility.

Emergence of resistant variants detected by ultra-deep sequencing after asunaprevir and daclatasvir combination therapy in patients infected with hepatitis C virus genotype 1

Daclatasvir (DCV) and asunaprevir (ASV) are NS5A and NS3 protease-targeted antivirals respectively, currently under development for the treatment of chronic hepatitis C virus (HCV) infection. We analysed the relationship between pre-existing drug-resistant variants and clinical outcome of the combination treatment with DCV and ASV. Ten patients with HCV genotype 1b were orally treated with a combination of ASV and DCV for 24 weeks. The frequencies of amino acid (aa) variants at NS3 aa positions 155, 156 and 168 and at NS5A aa31 and 93 before and after treatment were analysed by ultra-deep sequencing. We established a minimum variant frequency threshold of 0.3% based on plasmid sequencing. Sustained virological response (SVR) was achieved in 8 out of 10 patients (80%), and relapse of HCV RNA after cessation of the treatment and viral breakthrough occurred in the other two patients. Pre-existing DCV-resistant variants (L31V/M and/or Y93H; 0.9-99.4%) were detected in three out of eight patients who achieved SVR. Pre-existing DCV-resistant variants were detected in a relapsed patient (L31M, Y93H) and in a patient with viral breakthrough (Y93H); however, no ASV-resistant variants were detected. In these patients, HCV RNA rebounded with ASV- and DCV- double resistant variants (NS3 D168A/V plus NS5A L31M and Y93H). While pre-existing DCV-resistant variants might contribute to viral breakthrough in DCV and ASV combination therapy, the effectiveness of prediction of the outcome of therapy based on ultra-deep sequence analysis of pre-existing resistant variants appears limited.

Endothelial and inflammatory markers in relation to progression of ischaemic cerebral small-vessel disease and cognitive impairment: a 6-year longitudinal study in patients with type 2 diabetes mellitus

BACKGROUND

Progression of silent brain infarctions (SBIs) and white-matter lesions (WMLs) seen on brain MRI is associated with an increased risk of cognitive impairment, but their relation to endothelial and inflammatory markers is unknown in type 2 diabetes mellitus.

METHODS

In 190 type 2 diabetic outpatients (mean age 62.7 years), the authors related baseline levels of soluble intercellular adhesion molecule-1 (sICAM-1) and high-sensitivity C-reactive protein (hs-CRP) to subsequent brain MRI findings and cognitive function. The authors assessed incident SBIs and changes in periventricular and subcortical WMLs (PVWMLs and SCWMLs) on MRI performed at baseline and 3 and 6 years. Neuropsychological tests were administered to 83 patients older than 65 years at 6 years. This present study represents an extension of the authors' previously published study.

RESULTS

SBIs were observed in 46 patients (24.2%), PVWMLs in 93 (48.9%) and SCWMLs in 87 (45.8%) on baseline MRI. After adjustment for age, gender, hypertension, duration of diabetes, baseline MRI findings and medication use, the relative odds associated with a 1SD increase in sICAM-1 levels at baseline were 1.67 (95% CI 1.02 to 3.05) for SBI progression and 2.17 (95% CI 1.29 to 3.62) for PVWML progression at 6 years. In contrast, baseline hs-CRP levels were significantly associated with SBI progression only at 3 years. Significant trends were observed between quartiles of sICAM-1 at baseline and scores in Digit Symbol substitution (p for trend=0.01).

CONCLUSIONS

The findings suggest that higher sICAM-1 levels are associated with SBI and PVWML progression, and may predict impairment in psychomotor function in type 2 diabetes.

Mucosal muscarinic receptors enhance bladder activity in cats with feline interstitial cystitis

PURPOSE

Interstitial cystitis is a chronic pelvic pain syndrome of which the origin and mechanisms involved remain unclear. In this study Ca(2+) transients in the bladder wall of domestic cats diagnosed with naturally occurring feline interstitial cystitis were examined.

MATERIALS AND METHODS

Cross-sections of full-thickness bladder strips from normal cats and cats with feline interstitial cystitis were examined by optically mapping Ca(2+) transients and recording tension. Responses of Ca(2+) activity and detrusor contractions to pharmacological interventions were compared. In addition, pharmacological responses were compared in mucosa denuded preparations.

RESULTS

Optical mapping showed that feline interstitial cystitis bladders had significantly more spontaneous Ca(2+) transients in the mucosal layer than control bladders. Optical mapping also demonstrated that feline interstitial cystitis bladders were hypersensitive to a low dose (50 nM) of the muscarinic receptor agonist arecaidine when the mucosal layer was intact. This hypersensitivity was markedly decreased in mucosa denuded bladder strips.

CONCLUSIONS

In feline interstitial cystitis cat bladders there is increased Ca(2+) activity and sensitivity of muscarinic receptors in the mucosal layer, which can enhance smooth muscle spontaneous contractions.

Urotheliogenic modulation of intrinsic activity in spinal cord-transected rat bladders: role of mucosal muscarinic receptors

We examined the modulation of intrinsic (i.e., spontaneous) detrusor contractions by the urothelium and the lamina propria through optical mapping approaches. Normal adult and spinal cord-transected (SCT) rat bladders were stained with Ca2+- and voltage-sensitive dyes, and optical activity generated from intrinsic contractions was mapped from the mucosal surface of whole bladder sheets. Both normal adult and SCT rat bladders displayed intrinsic contractions, where normal bladders showed low-amplitude, high-frequency contractions with disorganized patterns of activity. In contrast, in the SCT animals there were high-amplitude, low-frequency contractions that displayed an organized spread of membrane potential and intracellular Ca2+. The difference in contractile activity was mirrored in the Ca2+ and membrane potential maps of bladder sheets. Normal bladders showed multiple initiation sites across the mucosal surface, whereas SCT bladders showed only one or two fixed initiation sites localized to the dome. The magnitude of intrinsic contractions could be enhanced by stretch or low-dose arecaidine (50 nM), a muscarinic-specific agonist. Partial removal of the mucosa decreased the amplitude of the intrinsic contractions and decreased the response to stretch or arecaidine. Optical mapping of mucosa-denuded sheets, where enhanced spontaneous activity was abolished, or application of 1 microM nifedipine to remove smooth muscle signals, but not the mucosal signals, shows that intrinsic activity in pathological bladders is driven by the mucosal layer. In summary, we suggest an urotheliogenic origin for intrinsic activity, where structures within the mucosal layer organize and thereby enhance intrinsic detrusor contractions.

Role of gap junctions in spontaneous activity of the rat bladder

Increased gap junction expression in lamina propria myofibroblasts and urothelial cells may be involved in detrusor overactivity, leading to incontinence. Immunohistochemistry was used to compare connexin (Cx) 26, 43, and 45 expression in the bladders of neonatal, adult, and spinal cord-transected rats, while optical imaging was used to map the spread of spontaneous activity and the effects of gap junction blockade. Female adult Sprague-Dawley rats were deeply anesthetized, a laminectomy was performed, and the spinal cord was transected (T8/T9). After 14 days, their bladders and those of age-matched adults (4 mo old) and neonates (7-21 day old) were excised and studied immunohistochemically using frozen sections or optically using whole bladders stained with voltage- and Ca(2+)-sensitive dyes. The expression of Cx26 was localized to the urothelium, Cx43 to the lamina propria myofibroblasts, and Cx45 to the detrusor smooth muscle. While the expression of Cx45 was comparable in all bladders, the expression of Cx43 and Cx26 was increased in neonate and transected animals. In the bladders of adults, spontaneous activity was initiated at multiple sites, resulting in a lack of coordination. Alternatively, in neonate and transected animals spontaneous activity was initiated at a focal site near the dome and spread in a coordinated fashion throughout the bladder. Gap junction blockade (18beta-glycyrrhetinic acid, 1 microM) abolished this coordinated activity but had no effect on the uncoordinated activity in adult bladders. These data suggest that coordinated spontaneous activity requires gap junction upregulation in urothelial cells and lamina propria myofibroblasts.

Origin of spontaneous activity in neonatal and adult rat bladders and its enhancement by stretch and muscarinic agonists

This study examined the origin of spontaneous activity in neonatal and adult rat bladders and the effect of stretch and muscarinic agonists and antagonists on spontaneous activity. Rats were anesthetized and their bladders were excised, cannulated, and loaded with voltage- and Ca(2+)-sensitive dyes. Intracellular Ca(2+) and membrane potential transients were mapped using photodiode arrays in whole bladders, bladder sheets, or cross-section preparations at 37 degrees C. Intravesical pressure was recorded from whole bladders. In neonatal bladders and sheets, spontaneous Ca(2+) and electrical signals arose at a site near the dome and spread in a coordinated manner throughout the bladder with different dome-to-neck conduction velocities (Ca(2+): 3.7 +/- 0.4 mm/s; membrane potential: 46.2 +/- 3.1 mm/s). In whole bladders, optical signals were associated with spontaneous contractions (10-20 cmH(2)O). By contrast, in adult bladders spontaneous Ca(2+) and electrical activity was uncoordinated, originating at multiple sites and was associated with smaller (2-5 cmH(2)O) contractions. Spontaneous contractions and optical signals were insensitive to tetrodotoxin (2 muM) but were blocked by nifedipine (10 muM). Stretch or low carbachol concentrations (50 nM) applied to neonatal whole bladders enhanced the amplitude (to 20-35 cmH(2)O) of spontaneous activity, which was blocked by atropine. Bladder cross sections revealed that Ca(2+) and membrane potential transients produced by stretch or carbachol began near the urothelial-suburothelial interface and then spread to the detrusor. In conclusion, spontaneous activity in neonatal bladders, unlike activity in adult bladders, is highly organized, originating in the urothelium-suburothelium near the dome. Activity is enhanced by stretch or carbachol and this enhancement is blocked by atropine. It is hypothesized that acetylcholine is released from the urothelium during bladder filling to enhance spontaneous activity.

Intranasal lidocaine 8% spray for second-division trigeminal neuralgia

BACKGROUND

Trigeminal nerve block has been widely used for trigeminal neuralgia. This may induce paraesthesia. The second division of the trigeminal nerve passes through the sphenopalatine ganglion, which is located posterior to the middle turbinate and is covered by a mucous membrane. We examined the effectiveness of intranasal lidocaine 8% spray on paroxysmal pain in second-division trigeminal neuralgia.

METHODS

Twenty-five patients with second-division trigeminal neuralgia were randomized to receive two sprays (0.2 ml) of either lidocaine 8% or saline placebo in the affected nostril using a metered-dose spray. After a 7 day period, patients were crossed over to receive the alternative treatment. The paroxysmal pain triggered by touching or moving face was assessed with a 10 cm visual analogue scale (VAS) before and 15 min after treatment. Patients used a descriptive scale to grade pain outcome, and were asked to note whether the pain returned and how long after therapy it recurred.

RESULTS

Intranasal lidocaine 8% spray significantly decreased VAS [baseline: 8.0 (2.0) cm, 15 min postspray: 1.5 (1.9) cm, mean (SD)], whereas the placebo spray did not [7.9 (2.0) cm, 7.6 (2.0) cm]. Moreover, pain was described as moderate or better by 23 patients of the lidocaine spray and 1 of the placebo group. The effect of treatment persisted for 4.3 h (range 0.5-24 h).

CONCLUSIONS

Intranasal lidocaine 8% administered by a metered-dose spray produced prompt but temporary analgesia without serious adverse reactions in patients with second-division trigeminal neuralgia.

Symposium Report on Urothelial Dysfunction: Pathophysiology and Novel Therapies

PURPOSE

The basic premise of this symposium (Workshop 7) at the 2004 International Continence Society meeting in Paris was to elucidate different mechanisms of urothelial cell pathology, explore their impact on bladder function and discuss novel therapeutic interventions.

RESULTS

The topics included 1) urothelial structure and function, 2) the role of adenosine triphosphate in urothelial signaling and cystitis, 3) lamina propria myofibroblasts and purinergic receptors, 4) antiproliferative factor involvement in interstitial cystitis, 5) the urothelium as a reservoir for bacterial infections, 6) radiation cystitis, nitric oxide and gene therapy, and 7) intravesical treatments.

DISCUSSION

It was agreed that the urothelium can no longer be regarded merely as a passive barrier separating urine from the underlying tissues. The epithelial cells of the urothelium form part of an integrated network that also includes afferent and possibly efferent nerves, and suburothelial myofibroblasts. It has a central role in several functions, including bladder wall sensation, local blood flow modulation, pathogen removal and active barrier provision. These functions are achieved through several autocrine and paracrine pathways that involve transmitter release from the urothelium and its ability to integrate incoming signals through its battery of membrane receptors. Several pathological processes were discussed using this knowledge, including the role of small glycoproteins released during interstitial cystitis, the molecular basis of radiation induced urothelial damage, the origin of recurrent urinary tract infections and the mode of action of potential intravesical treatments for overactive bladder.

CONCLUSIONS

Overall it was concluded that the urothelium has a key role in regulating lower urinary tract physiology and pathology.

Painful neuropathy alters the effect of gabapentin on sensory neuron excitability in rats

BACKGROUND

Pain following peripheral nerve injury is associated with increased excitability of sensory neurons. Gabapentin (GBP), a novel anticonvulsant with an uncertain mechanism of action, is an effective treatment for neuropathic pain. We therefore investigated the effect of GBP on dorsal root ganglion (DRG) neurons from normal rats and those with painful peripheral nerve injury.

METHODS

Dorsal root ganglions were excised from rats with neuropathic pain behaviour following chronic constriction injury (CCI) of the sciatic nerve, and from normal rats. Intercellular recordings were made from myelinated sensory neuron somata using a microelectrode technique from DRGs bathed in artificial CSF with or without GBP (100 microM).

RESULTS

Compared with normal neurons, injury decreased the refractory interval (RI) for repeat action potential (AP) generation increased the number of APs during sustained depolarization, and shortened the after hyperpolarization following an AP. In normal neurons, GBP decreased the RI and increased the AP number during sustained depolarization. In an opposite fashion, the result of GBP application to injured neurons was a decreased number of APs during depolarization and no change in RI. In injured neurons only, GBP increased the time-to-peak for AP depolarization.

CONCLUSIONS

Nerve injury by CCI is associated with increased sensory neuron excitability, associated with a decreased AHP. In normal peripheral sensory neurons, GBP has pro-excitatory effects, whereas GBP decreases excitability in injured neurons, possibly on the basis of altered sodium channel function.

H626R and R124C mutations of the TGFBI (BIGH3) gene caused lattice corneal dystrophy in Vietnamese people

BACKGROUND/AIMS

Mutations of the human transforming growth factor beta induced gene (TGFBI) were reported to cause lattice corneal dystrophy (LCD) in various nationalities. This study analysed the TGFBI gene in Vietnamese people with LCD.

METHODS

13 unrelated families, including 34 patients and 21 unaffected members were examined. 50 normal Vietnamese people served as controls. Blood samples were collected. Genomic DNA was extracted from leucocytes. Analysis of TGFBI gene was performed using the polymerase chain reaction and direct sequencing. Corneal buttons were studied histopathologically.

RESULTS

Two clinically distinguishable forms of LCD were revealed: one was typical of LCDI; the other was characterised by the late onset, thick lattice lines, and asymmetry between two eyes. Sequencing of the TGFBI gene revealed R124C mutation in three families and H626R mutation in 10 families. Congo red staining of the H626R-LCD cornea showed amyloid deposits in the subepithelial and stromal layers.

CONCLUSIONS

R124C and H626R mutations of TGFBI gene caused LCD in Vietnamese people. R124C, a common cause of LCDI in many nationalities, was relatively rare, whereas H626R reported in several white people but not yet in Asians was most common (>75%) in Vietnamese people. Since the phenotype caused by H626R represents a new variant intermediate between LCDI and LCDIIIA, we proposed to consider it as LCD type IIIB.

Analysis of the mouse transcriptome based on functional annotation of 60,770 full-length cDNAs

Only a small proportion of the mouse genome is transcribed into mature messenger RNA transcripts. There is an international collaborative effort to identify all full-length mRNA transcripts from the mouse, and to ensure that each is represented in a physical collection of clones. Here we report the manual annotation of 60,770 full-length mouse complementary DNA sequences. These are clustered into 33,409 'transcriptional units', contributing 90.1% of a newly established mouse transcriptome database. Of these transcriptional units, 4,258 are new protein-coding and 11,665 are new non-coding messages, indicating that non-coding RNA is a major component of the transcriptome. 41% of all transcriptional units showed evidence of alternative splicing. In protein-coding transcripts, 79% of splice variations altered the protein product. Whole-transcriptome analyses resulted in the identification of 2,431 sense-antisense pairs. The present work, completely supported by physical clones, provides the most comprehensive survey of a mammalian transcriptome so far, and is a valuable resource for functional genomics.

Corneal dystrophies in Japan

Recent advances in molecular genetics have increased our understanding of the role of genes. Four autosomal dominant corneal dystrophies (CDs); granular CD (GCD), Avellino CD (ACD), lattice CD (LCD), and Reis-Bücklers CD (RBCD) were mapped to the long arm of chromosome 5 (5q31). These four diseases were shown, in a Caucasian series, to result from different missense mutations in the TGFBI (BIGH3, keratoepithelin) gene. The same mutations were also detected in Japanese patients, from a different ethnic background. Gelatinous drop-like corneal dystrophy (GDLD), on the other hand, which was found in Japanese patients in 1914, is a rare autosomal recessive disorder characterized by corneal amyloidosis. Parents of the patients had a markedly higher frequency of consanguineous marriages than the general population. The gene responsible for GDLD, the membrane component, chromosome 1, surface marker 1 (M1S1) gene was mapped to the short arm of chromosome 1(1p). Four deleterious mutations in this gene were detected in Japanese patients. We review here additional studies on mutations of the TGFBI and M1S1 genes found in Japanese patients. In the TGFBI gene, nine different mutations were detected in Japanese patients with GCD, ACD, LCD, or RBCD. The codons R124 and R555 of the TGFBI gene were hotspots in Japanese patients, of whom many were ACD patients with the R124H mutation. New mutations responsible for LCD were detected in the TGFBI gene of patients with LCD, in addition to the P501T mutation in LCD type IIIA found earlier. These studies showed a clear genotype/phenotype correlation associated with the TGFBI gene. In the M1S1 gene, the Q118X mutation was the most common alteration, and a founder mutation in Japanese GDLD patients, as previously reported. Ninety-two percent of the mutated alleles were the Q118X.

The effect of cigarette smoking on soluble adhesion molecules in middle-aged patients with Type 2 diabetes mellitus

AIMS

To investigate the effect of smoking on soluble adhesion molecules in middle-aged diabetic patients.

METHODS

One hundred out-patients with Type 2 diabetes and 100 age- and sex-matched non-diabetic subjects without clinical macrovascular disease were selected. Soluble serum levels of adhesion molecules were analysed using enzyme immunoassay. Carotid atherosclerosis was assessed using an ultrasound system.

RESULTS

When compared with non-diabetic subjects, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and sE-selectin were found at significantly high levels in diabetic patients and significantly higher levels of sICAM-1, sE-selectin, and sP-selectin were observed in current smokers than never-smokers among diabetic or non-diabetic subjects, respectively. The combined, but not enhanced, effects of diabetes mellitus and smoking were observed in sICAM-1 and sE-selectin levels. Additionally, levels of sICAM-1 (P < 0.05) and sE-selectin (P < 0.01), but not sP-selectin, were high in ex-smokers when compared with never-smokers among diabetic patients. Diabetic smokers were also found to have marked carotid atherosclerosis, which was related to increased levels of sICAM-1.

CONCLUSIONS

Our present study shows that levels of adhesion molecules were higher in diabetic smokers than diabetic non-smokers or non-diabetic smokers, and that cessation after chronic smoking did not restore the levels of sICAM-1 and sE-selectin, though sP-selectin levels were restored. These data suggest a possible mechanism for accelerated atherosclerosis induced by smoking in patients with diabetes.

Three novel mutations of the RPGR gene exon ORF15 in three Japanese families with X-linked retinitis pigmentosa

We describe three new mutations in a recently identified exon, ORF15, of the retinitis pigmentosa GTPase regulator gene (RPGR) in three unrelated Japanese families (Families 1-3) with X-linked retinitis pigmentosa (XLRP). The affected males had typical retinitis pigmentosa (RP), whereas the obligate carrier females showed a wide clinical spectrum, ranging from minor symptoms to severe visual disability. Some carrier females in Families 1 and 2 showed typical RP, most carriers manifested high myopia and astigmatism, and their corrected visual acuity was insufficient. They showed an impairment of cone function following the rod dysfunction and accompanied by refractive errors. Microsatellite analysis of Family 1 revealed that the RP in the family was linked to the RP3 locus. Although one patient in the family had no mutation in the previously published exons 1-19 including exon 15a, he had a single-nucleotide insertion in exon ORF15 (g.ORF15 + 753-754 insG). Likewise, patients in Families 2 and 3 had two-base insertion/deletion in the exon, i.e., g.ORF15 + 833-834delGG and g.ORF15 + 861-862insGG, respectively. These insertional/deletional mutations observed in the three families are all different and new, and are predicted to lead to a frameshift, resulting in a truncated protein. These findings may support the previous hypothesis that RPGR-ORF15 is a mutational hot spot.

[Safety studies on collagen viscoelastic substance as an auxiliary agent in anterior segment surgery--assays of anti-collagen antibodies in blood and residual concentration of collagen in the anterior chamber of rabbits]

PURPOSE

Alkali-soluble collagen solution was assessed as a possible viscoelastic substance in anterior segment surgery, in terms of its safe applicability by assaying antigenicity, disappearance rate of collagen from the anterior chamber, and histopathological effect on the corneal tissue.

METHODS

The aqueous humor of rabbits was replaced with collagen solution three times. Then, follow-up clinical examinations with hand-slitlamp-microscopy, tonometry, pachymetry, and specular microscopy as well as ophthalmic histopathological examination were performed. Remaining collagen concentration in the aqueous humor at 1, 3, 5, 8, 24 and 72 hours after injection was determined to evaluate the disappearance rate of collagen from the aqueous humor with time. In vivo effects of chemical modification of collagen and buffer concentration on the corneal tissue were further studied by using transmission electron microscope (TEM) to find an optimum condition for collagen application.

RESULTS

Neither anti-collagen antibody formation, nor inflammatory responses in the anterior segment and systemic symptoms were observed even after 3 injections of collagen solution, except for 1 case which showed corneal opacity. As much as 97.4% of the collagen injected into the anterior chamber disappeared from the eyeball. On the basis of TEM findings, succinylated collagen in diluted phosphate buffer seems to be superior to alkali soluble collagen in terms of corneal tissue protection.

CONCLUSION

Collagen specifically prepared for this study showed no antigenecity and disappeared promptly from the anterior chamber. The optimal form of collagen in terms of corneal protection was discussed.

Studies on the uptake and release of fluoroquinolones by disposable contact lenses

PURPOSE

To evaluate the ability of three types of disposable contact lenses to take up and release three kinds of fluoroquinolones in vitro.

METHODS

We evaluated three FDA-approved disposable soft contact lenses (1-Day Acuvue, Medalist, and 14UV) for their ability to absorb and release three kinds of fluoroquinolones. Contact lenses were presoaked in fluoroquinolones for 1, 4, and 24 hours, and the uptake was determined by measuring the concentration of fluoroquinolones in the three types of disposable soft contact lenses by high pressure liquid chromatography (HPLC). After uptake, the lenses were placed in fresh saline baths, and release rates from the lenses were determined by measuring the concentration of fluoroquinolones in the saline baths by HPLC.

RESULTS

The disposable soft contact lens with the highest uptake of fluoroquinolones was the 1-Day Acuvue. After presoaking, drug concentrations in the 1-Day Acuvue and Medalist were higher than their theoretical saturation concentrations (i.e., the concentration of the fluoroquinolone eye drops [0.3%]). The release rates from the 1-Day Acuvue and Medalist lenses were slower than for the 14 UV lens.

CONCLUSIONS

These results indicate that among the lenses tested, the most practical drug delivery system is the 1-Day Acuvue disposable soft contact lens.

Disposable 1-day Acuvue contact lenses for the delivery of lomefloxacin to rabbits' eyes

PURPOSE

To investigate the ability of a disposable soft contact lens (1-Day Acuvue) to deliver lomefloxacin, a fluoroquinolones antibiotic, into the cornea and aqueous humor of rabbits.

METHODS

Experiments were conducted on adult albino rabbits. 1-Day Acuvue lenses were immersed for 1 hour in commercially-available lomefloxacin eye solution and then placed on the cornea. After 0.5, 2, 4,6, and 8 hours, the animals were killed and the lenses were removed and placed into a 20 mL saline bath. Corneal tissue and aqueous humor samples were also obtained at these times. The release of lomefloxacin from the lenses was calculated by measuring the amount of drug remaining in the lenses after removal from the rabbit eyes. The concentration of lomefloxacin in the cornea and anterior chamber following the wearing of lomefloxacin-loaded lenses was compared with the concentrations following frequent-drop therapy (one drop of lomefloxacin hourly for 8 hours).

RESULTS

In vivo, lomefloxacin was released from 1-Day Acuvue lenses gradually over 8 hours. The cornea and aqueous humor levels in the eyes following the wear of lomefloxacin-loaded lenses were significantly higher than those achieved by frequent-drop therapy. The drug levels in the cornea and aqueous humor generally remained above the 90% minimal inhibitory concentration for 8 hours in the 1-Day Acuvue lens group.

CONCLUSIONS

1-Day Acuvue contact lenses soaked in 0.3% lomefloxacin can release sufficient amounts of lomefloxacin and in this study produced higher levels in both the cornea and aqueous humor than that achieved by frequent-drop therapy for up to 8 hours. We conclude that 1-Day Acuvue contact lens can be used as a drug delivery system for lomefloxacin.

[Endogenous substance P in corneal epithelial cells and keratocytes]

PURPOSE

To detect endogenous substance P(SP) and neurokinin receptor 1(NK1R) in cultured human epithelial cells of the cornea(HE) and human keratocytes(HK).

METHOD

Messenger RNA(mRNA) expression of SP and endogenous SP in HE and HK were detected by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). mRNA expression of NK1R in HE and HK was detected by RT-PCR.

RESULTS

The mRNA expression of SP and endogenous SP were recognized in HE and HK. The mRNA of NK1R was also expressed in HE and HK.

CONCLUSION

It appears that endogenous SP regulates the biological functions of HE and HK in an autocrine or paracrine fashion.

Low-concentration lidocaine rapidly inhibits axonal transport in cultured mouse dorsal root ganglion neurons

BACKGROUND

Axonal transport plays a critical role in supplying materials for a variety of neuronal functions such as morphogenetic plasticity, synaptic transmission, and cell survival. In the current study, the authors investigated the effects of the analgesic agent lidocaine on axonal transport in neurites of cultured mouse dorsal root ganglion neurons. In relation to their effects, the effects of lidocaine on the growth rate of the neurite were also examined.

METHODS

Isolated mouse dorsal root ganglion cells were cultured for 48 h until full growth of neurites. Video-enhanced microscopy was used to observe particles transported within neurites and to measure the neurite growth during control conditions and in the presence of lidocaine.

RESULTS

Application of 30 microM lidocaine immediately reduced the number of particles transported in anterograde and retrograde axonal directions. These effects were persistently observed during the application (26 min) and were reversed by lidocaine washout. The inhibitory effect was dose-dependent at concentrations from 0.1 to 1,000 microM (IC50 = 10 microM). In Ca2+-free extracellular medium, lidocaine failed to inhibit axonal transport. Calcium ionophore A23187 (0.1 microM) reduced axonal transport in both directions. The inhibitory effects of lidocaine and A23187 were abrogated by 10 microM KN-62, a Ca2+-calmodulin-dependent protein kinase II inhibitor. Application of such low-concentration lidocaine (30 microM) for 30 min reduced the growth rate of neurites, and this effect was also blocked by KN-62.

CONCLUSIONS

Low-concentration lidocaine rapidly inhibits axonal transport and neurite growth via activation of calmodulin-dependent protein kinase II.

Late-onset form of lattice corneal dystrophy caused by leu527Arg mutation of the TGFBI gene

PURPOSE

To report two Japanese patients who were clinically diagnosed with late-onset and sporadic lattice corneal dystrophy (LCD) in whom a Leu527Arg mutation in the TGFBI gene was found.

METHODS

Molecular genetic analysis was performed on DNA extracted from peripheral leukocytes from the patients. Exons 4, 11, and 12 of the TGFBI gene were amplified by polymerase chain reaction and directly sequenced. Histopathologic study was performed on the corneal tissue obtained during deep lamellar keratoplasty (DLK) from one of the patients.

RESULTS

Patient 1 was a 74-year-old man who noticed a visual disturbance at the age of 72 years. Deep stromal opacities with nodular deposits and thick lattice lines were observed only in the right cornea, and DLK was performed. Patient 2 was an 82-year-old man who had LCD (similar in appearance to that in patient 1) in both eyes without visual disturbance. Neither of the patients had a family history of corneal problems and had no episode of corneal erosion. A heterozygous single base-pair transition (CTG to CGG, leucine to arginin) was detected in codon 527 of the TGFBI gene in both patients. No mutation was found in codons 124, 501, 518, 546, or 555. Histopathologically, relatively large amyloid deposits in the deep corneal stroma and ribbons of amyloid deposits just beneath the Bowman's layer were observed in the corneal tissue of patient 1.

CONCLUSIONS

Clinical features and pathologic findings of the late-onset form of LCD with an L527R mutation in the TGFBI gene were made clear.

[The present state of blindness in the world]

PURPOSE

To investigate the present state of blindness around the world.

METHODS

The article reviews significant studies by WHO and literature on the topic.

RESULTS

Current global estimates indicate that blindness affects close to 45 million people, with nine out of ten blind people living in developing countries. Two-thirds or more of all blindness is avoidable, in that the causes are preventable or treatable. Cataract is the major cause of blindness in the world and the number of cases is increasing. The second cause is glaucoma, and the third is trachoma. The extent of disability of blindness itself is very high compared to that of other illnesses. Also, in terms of the burden of diseases in society, blindness is a relatively huge problem in the developing world.

CONCLUSIONS

Intervention should be focused on the factors that have the higheat possibility of change. Manpower development is the most important countermeasure. The aid required to support developing countries is what can make them stand on their own in long term ophthalmic care.

[Amiodarone-induced keratopathy]

BACKGROUND

We studied 17 patients who received oral administration of amiodarone.

CASES

The patients were 13 males and 4 females with the mean age of 65.7 years. The periods of follow-up observation ranged from 120 to 1,085 days. Keratopathy was found in 7 cases(41.2%), during the follow-up period. The grade of keratopathy showed no fixed tendency in age, total drug dose, or duration of administration, nor was there any correlation between the grade on the one hand and the period from inception of amiodarone administration to the development of keratopathy and total drug dose on the other. The effects of amiodarone on the cornea, conjunctival epithelium, anterior subcapsular lens, and tear fluid were studied histologically in 2 cases. Effects of amiodarone were found in the cornea and anterior subcapsular lens, but not in the conjunctival epithelium and tear fluid.

CONCLUSION

It is possible that keratopathy may be an indicator for long-term administration and for predicting the development of other complications of amiodarone.

The expression of laminin-5 and ultrastructure of the interface between basal cells and underlying stroma in the keratoconus cornea

PURPOSE

We investigated the expression of laminin-5 and integrins, and the ultrastructure of the interface between basal cells and the basement membrane in the keratoconus cornea. These findings were compared to those in normal central cornea and limbus.

METHODS

Frozen sections of the normal cornea (center and limbus) and the keratoconus cornea were immunostained with monoclonal antibodies against three chains of laminin-5 and integrins. To investigate the ultrastructure of the interface between basal cells and the underlying stroma, we used transmission electron microscopy.

RESULTS

As compared to those in the normal central cornea, immunostaining patterns of the three chains of laminin-5 were thick and irregular in the keratoconus cornea and the normal limbus. Using electron microscopy analysis, the same characteristic structure of the interface between basal cells and the underlying stroma was recognized in the keratoconus cornea and the normal limbus. The expression of integrin alpha(6)beta(4) was restricted to the basal aspect of basal cells in the normal cornea. In the keratoconus cornea, however, integrin alpha(6)beta(4) was expressed in all aspects in basal and suprabasal cells. CONCLUSION The expression patterns of laminin-5 and the ultrastructure of the interface between basal cells and the basement membrane in the keratoconus cornea were similar to those in the normal limbus.

Effects of topical unoprostone and latanoprost on acute and recurrent herpetic keratitis in the rabbit

PURPOSE

To determine the effect of the topical ocular hypotensive drug, isopropyl unoprostone, a docosanoid molecule with very weak prostaglandin activity, on herpes keratitis in the rabbit eye.

METHODS

For acute disease, rabbit corneas inoculated with the corticosteroid-sensitive F(MP)E strain of herpes simplex virus type 1 were treated with various combinations of 0.12% isopropyl unoprostone, latanoprost, trifluridine, benzalkonium chloride 0.02%, dexamethasone sodium phosphate, ketorolac tromethamine, or saline solution beginning 1 day after infection. Severity of keratitis was evaluated in a masked manner. For recurrent disease, rabbit corneas infected with McKrae strain herpes simplex virus type 1 were treated with unoprostone or saline solution on postinfection days 25 to 42, and the presence or absence of lesions was recorded.

RESULTS

Eyes treated with unoprostone showed significantly less severe disease than saline-treated or latanoprost-treated eyes during acute infection. Unoprostone-treated and saline-treated eyes showed no significant difference in the frequency of recurrent lesions. Eyes treated with latanoprost and/or dexamethasone, separately or in combination, showed increased severity of acute herpes simplex virus keratitis, whereas benzalkonium chloride 0.02%--treated eyes showed no significant difference, compared with saline treatment. Trifluridine resulted in rapid healing.

CONCLUSIONS

Unoprostone did not increase the severity or recurrence rate of herpes simplex virus keratitis. Unoprostone requires twice-a-day administration, compared with once-a-day for latanoprost, and unoprostone lowers intraocular pressure less than latanoprost. Nevertheless, unoprostone's superior safety profile may make its use advantageous. Benzalkonium chloride alone did not make the keratitis worse.

Sensory blockade of S3 dermatome prevents pain during bladder catheterization

PURPOSE

We often encounter patients who do not complain of pain on undergoing invasive urogenital or rectal procedures, despite incomplete epidural blockade of sacral cutaneous sensation. To clarify whether or not urethral pain is blocked faster than sacral cutaneous sensation during lumbar epidural anesthesia, we investigated the correlation between occurrence of urethral pain and loss of cold sensation in the S1-3 dermatomes.

METHODS

In 46 gynecological patients, Group A (n=22) received 15 ml of 2% mepivacaine via an epidural catheter inserted cephaladly. Group B (n=24) received 5 ml of 2% mepivacaine directly in the epidural needle directed caudally and 10 ml of 2% mepivacaine via the epidural catheter inserted cephaladly. A Foley catheter was inserted into the urethra 30 min after the injection.

RESULTS

Urethral pain, which was defined as a pained facial expression and/or complaint of pain, was observed in seven patients in Group A, and none in Group B. The caudad level of epidural blockade was significantly lower in patients without urethral pain (S3, median) than with urethral pain (L4) (P <0.05). In 39 patients without urethral pain, 19 (49%) experienced loss of cold sensation in the S1 dermatome, 27 (69%) in the S2 and 38 (97%) in the S3 25 min after the injection.

CONCLUSION

Blockade of urethral visceral pain often occurs before complete sacral somatosensory blockade, and S3 somatosensory blockade is the important sacral level as an indicator of successful urethral sensory blockade.

Study on Collagen Viscoelastic Substance as an Auxiliary Agent in Anterior Segment Surgery. Ocular Irritation Study by Replace ment of the Aqueous Humor in Rabbits

Purpose: Collagen solution was assessed as a possible visoelastic substance in anterior segment surgery, in terms of the depth of the anterior chamber and ocular irritation.Methods: The depth of the anterior chamber of enucleated rabbit eyes was evaluated 5 minutes after injection of collagen solution. For ocular irritation test, the aqueous humor of rabbits was replaced with collagen using sodium hyaluronate (HEALON((R))) and phosphate buffer (PB) as controls. Follow-up clinical examinations with hand-slit-lamp-microscopy, tonometry, pachymetry, and specular microscopy were performed for 7 days or 28 days, and then aqueous humor, corneal endothelium, and eye tissues were evaluated by gel electrophoresis, scanning electron microscopy, and light microscopy, respectively.Results: 2.5% to 3% collagen solution was found to be optimal for maintaining the depth of the anterior chamber. No significant differences in clinical findings such as anterior chamber and corneal thickness or in biochemical and histological findings were observed among collagen-, hyaluronate- and PB-treated groups, except for intraocular pressure which was increased in the hyaluronate-treated group, but not in the collagen-treated group.Conclusion: Collagen specifically prepared for this study seems to be an excellent auxiliary agent for anterior segment surgery, providing an appropriate anterior chamber with little ocular irritation. (Jpn Ophthalmol Soc 104:458-65, 2000)

Decreased GlcNAc 6-O-sulfotransferase activity in the cornea with macular corneal dystrophy

PURPOSE

Macular corneal dystrophy (MCD) is an autosomal recessive inherited disorder that is accompanied by corneal opacity. Explants from MCD-affected corneas have been reported to synthesize low-sulfated KS, suggesting that sulfate groups attached to KS may play critical roles in maintaining corneal transparency. To clear the biosynthetic defect in the MCD cornea, sulfotransferase activities were determined that are presumably involved in the biosynthesis of KS: galactose-6-sulfotransferase (Gal6ST) activity and N-acetylglucosamine 6-O-sulfotransferase (GlcNAc6ST) activity.

METHODS

Gal6ST and GlcNAc6ST activities, which were contained in the corneal extracts from corneas affected by MCD and keratoconus and from normal control corneas, were determined by measuring the transfer of (35)SO(4) from [(35)S]3'-phosphoadenosine 5'-phosphosulfate into the Gal residue of partially desulfated KS and the nonreducing terminal GlcNAc residue of GlcNAcbeta1-3Galbeta1-4GlcNAc (oligo A), respectively.

RESULTS

The level of Gal6ST activity in corneal extracts from eyes with MCD, which was measured by using partially desulfated KS as an acceptor, was nearly equal to that in eyes with keratoconus and normal control eyes. In contrast, GlcNAc6ST activity in the extracts from MCD-affected corneas, which was measured by using oligo A as an acceptor, was much lower than in those in corneas with keratoconus and in normal control corneas.

CONCLUSIONS

The decrease in GlcNAc6ST activity in the cornea with MCD may result in the occurrence of low- or nonsulfated KS and thereby cause corneal opacity.

Six different mutations of TGFBI (betaig-h3, keratoepithelin) gene found in Japanese corneal dystrophies

PURPOSE

To investigate mutations of the human transforming growth factor beta-induced gene (TGFBI), transforming growth factor-beta-induced gene product (betaig-h3, keratoepithelin), in Japanese patients with Avellino corneal dystrophy (ACD), lattice corneal dystrophy (LCD), granular corneal dystrophy (GCD), and Reis-Bücklers corneal dystrophy (RBCD).

METHODS

Genomic DNA was extracted from the peripheral blood of 75 patients and 7 unaffected relatives from 60 families with ACD, 34 patients and 8 unaffected relatives from 21 families with LCD, 4 patients and 4 unaffected relatives from 4 families with GCD, and 4 patients and an unaffected relative from 3 families with RBCD. Fifty normal volunteers served as controls. Exons 4, 11, and 12 of the TGFBI gene were amplified by polymerase chain reaction and were directly sequenced.

RESULTS

Six different heterozygous missense mutations were detected in codons R124, L518, L527, and R555 of the TGFBI gene in the 117 patients from 88 families. A R124H mutation was detected in the patients with ACD. A R124C mutation was detected in the patients with LCD type 1 (LCD1), L518P was in atypical LCDI, and L527R in LCD with opacities deep in stroma. A R555W mutation was detected in the patients with GCD. A R555Q mutation was detected in the patients with RBCD.

CONCLUSIONS

We conclude that codons R124 and R555 of the TGFBI gene are also hot spots in Japanese patients with ACD, LCD, GCD, and RBCD. Many Japanese patients with CD had ACD with R124H mutation. GCD with R555W mutation was rare.

Visual function in retinitis pigmentosa related to a codon 15 rhodopsin gene mutation

To determine the phenotype of a Japanese family in which retinitis pigmentosa cosegregates with a rhodopsin gene mutation, i.e. an asparagine-to-serine change at codon 15 (Asn-15-Ser), 5 affected and 5 unaffected members of one pedigree underwent several ophthalmic examinations as well as Ganzfeld electroretinography (ERG) and multifocal ERG. Genomic DNA samples were analyzed by PCR amplification, sequencing and restriction enzyme digestion. A codon 15 rhodopsin gene mutation (Asn-15-Ser) was found in all affected members. The region of pigmentary degeneration was localized in the lower hemiretina, and visual field defects corresponded to the retinal pigmentary changes. Scotopic ERG amplitudes, rather than photopic ERG amplitudes, were reduced. Multifocal ERG revealed a low magnitude of response density, even for the upper hemiretina, which showed no bony corpuscle pigmentation. Visual function in sectorial retinitis pigmentosa associated with rhodopsin gene codon 15 mutation is on the basis of the rod-cone dystrophy, regardless of differences in phenotypic expression.

Distribution and isoform characterization of type XII collagen in bovine cornea

Streptavidin peroxidase immunohistochemistry and immunoelectron microscopy were used to determine the localization of type XII collagen in sections from bovine corneas. Type XII collagen extracted from bovine cornea and skin was assayed by Western blotting. Immunohistochemical experiments showed that type XII collagen was restricted to the corneal stroma; it was not present in corneal epithelium, epithelial basement membrane, Descemet's membrane or endothelium. Type XII collagen was distributed throughout the corneal stroma, and it was prominently localized at the superficial stroma. Immunoelectron-microscopic examination demonstrated that type XII collagen was regularly found along the surface of banded collagen fibrils with a periodic distribution. By Western blot analysis, we observed that extracts from bovine cornea contained both the long and short isoforms of type XII collagen, whereas extracts from bovine skin contained only the short isoform. The homogeneous distribution and/or presence of the long isoform of type XII collagen may be related to the characteristically regular arrangement of collagen fibrils and thereby the transparency of corneal tissue.

Novel mutations in the myocilin gene in Japanese glaucoma patients

Myocilin is a gene responsible for juvenile onset primary open angle glaucoma (POAG) mapped as the GLC1A locus and, many mutations have been reported worldwide. Some mutations were found not only in patients with juvenile onset POAG, but also in patients with late onset POAG and in patients with normal tension glaucoma. To investigate the mutation prevalence in Japan, we performed a mutation analysis in 140 unrelated Japanese patients. We have identified the 10 sequence variants, of which four were highly probable for disease-causing mutations (Arg46ter, Arg158Gln, Ile360Asn, and Ala363Thr), and six polymorphisms (Gln19His, Arg76Lys, Asp208Glu, Val439Val, Arg470His, and Ala488Ala). Thus, myocilin mutations were found at the rate of 4/140 (2.9%) probands, similar to previous reports with other ethnic populations.

Secondary keratoconus with corneal epithelial iron ring similar to Fleischer's ring

BACKGROUND

Fleischer's ring is considered to be a characteristic of keratoconus, but we have seen a ring similar to Fleischer's ring in patients with secondary keratoconus, in which the cornea becomes thinner secondarily for undetermined reasons.

CASES

We report 6 cases of secondary keratoconus with a corneal epithelial ring similar to the Fleischer's ring pattern.

OBSERVATIONS

In these 6 cases (2 men and 4 women), the causes of secondary keratoconus were trachoma in 2 cases, trauma in 2 cases, keratitis in 1 case and unknown etiology in one case. All showed thinning of the cornea and a corneal iron ring similar to Fleischer's ring pattern. The corneal button obtained after keratoplasty in 1 case showed the deposition of hemosiderin in the corneal epithelium after staining with Prussian blue. At the same time we confirmed the existence of iron in the corneal epithelium by x-ray ultimate analysis.

CONCLUSIONS

All 6 patients we encountered had a past history of corneal disease in their childhood except for 1 case with unknown etiology. Primary keratoconus is also considered to develop by the early teens at the latest. These facts led us to an assumption that the occurrence of some abnormalities in the cornea during the growth period may result in iron deposition in the epithelium and thinning of the stroma. In light of these facts, abnormalities of the iron metabolism must be thoroughly investigated in considering the etiology of keratoconus.

Trial for new intraocular lens power calculation following phototherapeutic keratectomy

PURPOSE

To determine an equation to calculate the intraocular lens (IOL) power for eyes that have undergone laser phototherapeutic keratectomy (PTK).

METHODS

The Gullstrand series was used to determine the power and radius of curvature of a convex-plane IOL, which will alter the focal point from the cornea to the conjugate point on the retina using the ray tracing method.

RESULTS

The radius of curvature of the anterior corneal surface (R), axial length (AXL), the predicted postoperative anterior chamber depth (ACD), and lens thickness (LT) were used in the following formula to calculate the refractive power of the IOL to be used: K = R/7.7, DC = 337.5/R, VC = lOOO/DC x 1.336 where VC is the posterior vertex focal length, A(1) = -(VC - ACD), B(1) = AXL - 0.5 x K - ACD - 0.103LT, S = l/A(1) + l/B(1), K is the proportional expression for anterior corneal curvature, DC = anterior corneal refractive power, A(1) = distance from anterior surface of IOL to posterior vertex focal point, B(1) = distance from the second principal point of IOL to the retina, S = 1/focal length of IOL in air. Using this equation, the power (in diopters) of the IOL in liquid was determined to be 1000/(l/S). 1. 336. In eyes that have undergone PTK, the keratometric value prior to cataract surgery is not used. Instead a value, R', is introduced. R' is defined as (R - 376/1376. dT), where R is the radius of corneal curvature prior to PTK and dT the amount of corneal tissue removed. The corneal thickness after cataract surgery, CT', was defined as CT - dT, where CT is the corneal thickness prior to PTK.

CONCLUSION

The new equation appears to be useful for determining the IOL power, although it is important to select a lens that has the accurate predicted anterior chamber depth.

The functions of exogenous and endogenous laminin-5 on corneal epithelial cells

Recent evidence suggests that the basement membrane not only separates basal cells from Bowman's layer, but also has a crucial role in the proliferation, differentiation and migration of corneal epithelial cells. The basement membrane is composed of a mixture of matrix components including collagens, laminins and heparan sulfate proteoglycans. In these extracellular matrixes, laminin is a major component of the basement membrane. Of 11 laminin isoformes, laminin-5 is a variant, composed of three nonidentical subunits alpha3, beta3, gamma2 and is a major component of the corneal basement membrane. However, little is known about the interactions of laminin-5 with corneal epithelial cells. In this study, we investigated the functions of laminin-5 on SV-40 transfected human corneal epithelial cells (HCE cells). We also revealed different functions between exogenous and endogenous laminin-5 on HCE cells. Laminin-5 is synthesized initially as a 490 kDa molecule that undergoes specific processing to cleavaged isoforms after being secreted. The alpha3 subunit is processed from 200-190 kDa to 160 kDa/145 kDa. The gamma2 subunit is processed from 150 kDa to 105 kDa/80 kDa. The beta3 subunit (140 kDa) is not processed. Exogenously added laminin-5 (soluble form) in this study was purified from a serum-free, conditioned medium of a human gastric carcinoma cell line STKM-I. This soluble laminin is a processed isoform containing alpha3 (160 kDa), beta3 (140 kDa) and gamma2 (105 kDa) chains. On the other hand, immunocytochemical analysis showed that HCE cells themselves secreted laminin-5 endogenously. Western blotting analysis revealed that HCE cells initially produced unprocessed isoform containing 190 kDa alpha3, 140 kDa beta3 and 150 kDa gamma2 chains and that after being secreted, the alpha3 chain was processed to 160 kDa/145 kDa and the gamma2 chain was processed to 105 kDa. Initially we investigated the functions of exogenous (processed) laminin-5 on HCE cells. Exogenously added laminin-5 strongly promoted cell adhesion via alpha3beta1 integrin, cell spreading, assembly of hemidesmosomes and mildly inhibited cell migration. Next we estimated the effect of endogenous (unprocessed) laminin-5 on HCE cells. Using an anti laminin-5 monoclonal antibody (mAb) or anti integrin alpha3beta1 mAbs, the blocking of the interaction between endogenously secreted laminin-5 and HCE cells caused strong inhibition of cell migration. Integrin alpha3beta1 and alpha6beta4 were expressed in HCE cells. These integrins are receptors of laminin-5. But, anti integrin alpha6beta4 mAbs did not have any blocking ability against cell migration. These results indicated that endogenous (unprocessed) laminin-5 has a crucial role in cell migration on HCE cells via alpha3beta1 integrin. In conclusion, structural differences between exogenous (processed) and endogenous (unprocessed) laminin-5 regulated their functions on HCE cells. Exogenously added laminin-5 strongly promoted cell adhesion, cell spreading and assembly of hemidesmosomes. Endogenously secreted laminin-5 had a crucial role in cell migration. In the future, processed soluble laminin-5 could be a useful drug for the prevention of recurrent corneal erosion, and unprocessed soluble laminin-5 could be applied for the treatment of prolonged corneal epithelial defects.

Q118X mutation of M1S1 gene caused gelatinous drop-like corneal dystrophy: the P501T of BIGH3 gene found in a family with gelatinous drop-like corneal dystrophy

PURPOSE

To analyze BIGH3 and M1S1 genes in two Japanese brothers with gelatinous drop-like corneal dystrophy and five unaffected family members.

METHODS

DNA was extracted, and each part of the two genes was amplified and directly sequenced.

RESULTS

On the BIGH3 gene, a heterozygous P501T mutation was found in the elder brother and three unaffected family members. On the M1S1 gene, both brothers with gelatinous drop-like corneal dystrophy showed a homozygous Q118X mutation, whereas all unaffected members were heterozygous.

CONCLUSIONS

The Q118X mutation of M1S1 gene caused gelatinous drop-like corneal dystrophy. Although the P501T of the BIGH3 gene found in this pedigree was precisely the one reported for lattice corneal dystrophy IIIA, no clinical feature was shown, even in the 85-year-old father. This fact shows that the P501T mutation for LCDIIIA has low penetrance.

Corneal wound healing: Immunohistological features of extracellular matrix following penetrating keratoplasty in rabbits

PURPOSE

To study the distribution and the constituents of the extracellular matrix in the cornea during wound healing following penetrating keratoplasty (PKP).

METHODS

Penetrating keratoplasty (PKP) was performed on albino rabbit eyes, and immunohistochemical techniques were used to determine the distribution of types I, III, IV collagens, large proteoglycans, chondroitin 6-sulfate, chondroitin 4-sulfate, and vimentin. The expression of these substances was determined at postoperative times of 3 days, 1 week, 2 weeks, 1 month, and 3 months.

RESULTS

By day 3, staining for type IV collagen was observed along the host-graft junction. By day 7, staining for type III collagen, large proteoglycans, and chondroitin 6-sulfate had increased in the repair region but then decreased with increasing postoperative times. Epithelial wound healing required more than one month, whereas the remodeling of Descemet's membrane did not terminate until 3 months after PKP.

CONCLUSION

These results suggest that type III collagen, large proteoglycans, and chondroitin 6-sulfate probably play important roles in corneal wound healing after PKP.

[Study on collagen viscoelastic substance as an auxiliary agent in anterior segment surgery--ocular irritation study by replacement of the aqueous humor in rabbits]

PURPOSE

Collagen solution was assessed as a possible viscoelastic substance in anterior segment surgery, in terms of the depth of the anterior chamber and ocular irritation.

METHODS

The depth of the anterior chamber of enucleated rabbit eyes was evaluated 5 minutes after injection of collagen solution. For ocular irritation test, the aqueous humor of rabbits was replaced with collagen using sodium hyaluronate (HEALON) and phosphate buffer (PB) as controls. Follow-up clinical examinations with hand-slit-lamp-microscopy, tonometry, pachymetry, and specular microscopy were performed for 7 days or 28 days, and then aqueous humor, corneal endothelium, and eye tissues were evaluated by gel electrophoresis, scanning electron microscopy, and light microscopy, respectively.

RESULTS

2.5% to 3% collagen solution was found to be optimal for maintaining the depth of the anterior chamber. No significant differences in clinical findings such as anterior chamber and corneal thickness or in biochemical and histological findings were observed among collagen-, hyaluronate- and PB-treated groups, except for intraocular pressure which was increased in the hyaluronate-treated group, but not in the collagen-treated group.

CONCLUSION

Collagen specifically prepared for this study seems to be an excellent auxiliary agent for anterior segment surgery, providing an appropriate anterior chamber with little ocular irritation.

Corneal amyloidosis caused by Leu518Pro mutation of betaig-h3 gene

AIM

To report a Japanese family diagnosed clinically as having lattice corneal dystrophy type I (LCDI) in which a Leu518Pro mutation in the betaig-h3 gene and not the R124C mutation reported previously was found.

METHODS

Molecular genetic analysis was performed on DNA extracted from peripheral leucocytes from four members (three affected and one unaffected) of a family. Exon 4 of the betaig-h3 gene was amplified by PCR and directly sequenced. Histopathological study was performed on the corneal tissue from the proband obtained during deep lamellar keratoplasty.

RESULTS

All the affected members were clinically diagnosed as having LCDI, and the pedigree indicated an autosomal dominant inheritance. A heterozygous single base pair transition (CTG to CCG, leucine to proline) was detected in codon 518 of the betaig-h3 gene in the three affected members, and not in the unaffected member. No mutation was found in codon 124. Amyloid deposits were observed between the collagen bundles of the corneal stroma and were seen to extend deep into the stroma.

CONCLUSION

The Leu518Pro mutated betaig-h3 forms amyloidogeneic intermediates which precipitate in the cornea and gives rise to a clinical appearance of LCDI.

[Intraocular lens calculation for cataract treated with photorefractive keratectomy using ray tracing method]

PURPOSE

Conventional methods (such as the SRK-II formula) do not accurately calculate the power of the intraocular lens (IOL) after refractive surgery. Therefore, we compared a new formula including a ray tracing method to the conventional method for foldable IOL lens implantation.

METHOD

Foldable IOLs (MA 60 BM) were implanted in 26 patients (32 eyes) using the phakoemulsification technique. The power of the IOL was measured preoperatively using the SRK-II formula in all cases. From the results of postoperative refractive errors of these cases, the power of IOL calculated by the ray tracing method was compared to the SRK-II formula. Cataract patients first treated with photorefractive keratectomy (PRK) received IOL implants using our ray tracing method and their postoperative refraction was measured.

RESULTS

The average postoperative refractive error was 1.32 D in SRK-II formula, 0.95 D in the ray tracing method with Ray 1 used and 0.89 D with Ray 2 used. Postoperative refraction of both eyes first treated with PRK was--1.00 D.

CONCLUSION

The average postoperative refractive error was reduced in the ray tracing method using Olsen's predicted ACD (Ray 2) compared to SRK-II formula. This new tracing method appears to be useful for determination of IOL power and it may be applied for IOL calculation for cataract surgery after refractive surgery.