Platelet volume indices correlate to severity of heart failure and have prognostic value for both cardiac and thrombotic events in patients with congenital heart disease

Introduction

Patients with heart failure are reported to have activated platelets leading to thrombotic events. Consequently, immature giant platelets are produced, and platelet distribution width (PDW) and mean platelet volume (MPV) increase. These platelet indices are easily, reasonably, and safely available by routine blood test and recently have been proposed as potential markers of cardiac events. However, little is known about the usefulness of platelet indices in patients with congenital heart disease (CHD).

Purpose

To test whether the hypothesis that PDW and MPV correlate to the severity of heart failure and have prognostic value in both future heart failure-related admission and thrombosis formation in patients with CHD.

Methods

We performed a retrospective, single-centre study that included 400 patients with CHD (median age, 34 years [range: 12–76]; 49% males; 35% single ventricular morphology), who were admitted in our institute between April 2014 and June 2017. We reviewed patients' medical records to assess their clinical information including medical history, blood sample data, and echocardiologic parameters. At first, we assessed the correlation between platelet indices and patients' clinical parameters. Next, we compared platelet indices before and after treatment for heart failure. Finally, using logistic regression and Kaplan-Meier analyses, we assessed prognostic factors of future heart failure-related admission and thrombosis formation.

Results

In multivariate analysis, a significant correlation was found between PDW and logBNP (brain natriuretic peptide) (p<0.001), haemoglobin (p=0.01), D-dimer (p=0.019), Fontan operation (p<0.001) and male sex (p<0.001); as well as between MPV and logBNP (p<0.001), D-dimer (p<0.001) and Fontan operation (p=0.002). Throughout treatment of heart failure, significant reduction was found both in PDW (average value before treatment = 14.2, after treatment = 13.2, p=0.002) and MPV (before = 11.2, after = 10.8, p=0.004). In multivariate logistic regression analysis, predictors of future heart failure-related admissions were PDW (hazard ratio [HR]: 1.365; 95% confidence interval [CI]: 1.005–1.768), MPV (HR: 1.472; 95% CI: 1.055–2.052), age (HR: 1.063; 95% CI: 1.010–1.119), and SpO2 under 85% (HR: 5.089; 95% CI: 1.350–19.18). Using the same analysis, predictors of thrombotic formation were PDW (HR: 1.998; 95% CI: 1.461–2.630), MPV (HR: 1.792; 95% CI: 1.155–2.781), logBNP (HR: 1.196, 95% CI: 1.085–1.320), D-dimer (HR: 1.024; 95% CI: 1.007–1.042) and male sex (HR: 3.071; 95% CI: 1.079–8.737). In addition, during median follow-up of 28 months, the Kaplan-Meier analysis showed an improvement in both heart failure and thrombosis-free survival in the low PDW, as well as the low MPV group.

Conclusion

Platelet volume indices correlate to severity of heart failure and have prognostic value for both cardiac and thrombotic events in patients with congenital heart disease.

Funding Acknowledgement

Type of funding source: None

P824The clinical impact of polyunsaturated fatty acid on clinical outcomes in acute coronary syndrome with dyslipidemia: HIJ-PROPER sub-analysis

Background

Polyunsaturated fatty acids, especially omega-3 and -6 series, are key essential nutrients that play an important role in humans to maintain cell membranes and function. A recent randomized trial reported that adding eicosapentaenoic acid (EPA) to statins was beneficial to cardiovascular disease patients who had a residual risk factor. Further, several studies have reported that the low baseline value for EPA to arachidonic acid (AA) ratio is related to worse clinical outcome and plaque vulnerability in coronary artery disease patients. However, effects of baseline EPA/AA ratio on clinical outcomes in ACS patients have not been thoroughly evaluated.

Objectives

This study aimed to examine the impact of baseline eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio on clinical outcomes of acute coronary syndrome (ACS) patients and how lipid-lowering therapy affects serum EPA/AA levels in these patients.

Methods

This is a sub-analysis of HIJ-PROPER assessing the effect of aggressive low-density lipoprotein cholesterol (LDL-C)-lowering treatment with pitavastatin+ezetimibe in 1,734 ACS patients with dyslipidemia. Patients were divided into two groups based on EPA/AA level on admission (cut-off: 0.34 μg/mL; median of baseline EPA/AA level) and clinical outcomes were examined.

Results

Percent reduction of LDL-C from baseline to follow-up and mean LDL-C level during follow-up were similar regardless of baseline EPA/AA ratio. In the low EPA/AA group, the Kaplan–Meier estimate for the primary endpoint at 3 years was 27.2% in the pitavastatin+ezetimibe group, compared with 36.6% in the pitavastatin-monotherapy group [hazard ratio (HR), 0.69; 95% confidence interval (CI), 0.52–0.93; P=0.015). However, in the high EPA/AA group, there was no significant reduction in the primary endpoint by pitavastatin+ezetimibe therapy (HR, 0.92; 95% CI, 0.70–1.20; P=0.52).

Conclusions

Aggressive lipid-lowering therapy with ezetimibe had a positive effect on clinical outcomes in the low EPA/AA group of ACS patients with dyslipidemia, but not in the high EPA/AA group. This effect was independent of LDL-C reduction and suggests that EPA/AA measurement on admission in ACS patients contributes to a “personalized” lipid-lowering approach.

Purification and characterization of the plasma membrane glycosidases of Drosophila melanogaster spermatozoa

Previous studies from our laboratory have demonstrated the presence of two integral proteins with glycosidase activity in the plasma membrane of Drosophila melanogaster spermatozoa and we have suggested that these enzymes might have a role in sperm-egg binding. In this study the glycosidases have been purified and characterized. We have evidenced the presence of three distinct enzymes, two beta-N-acetylhexosaminidase isoforms, named HEX 1 and HEX 2, and an alpha-mannosidase. The molecular size of the native enzymes estimated by gel filtration was 158 kDa for beta-hexosaminidases and 317 kDa for alpha-mannosidase. SDS-PAGE showed that HEX 1 and HEX 2 are dimers formed by subunits with different molecular sizes, whereas alpha-mannosidase consists of three subunits with different molecular weights. All the enzymes are terminally glycosylated. Characterization of the purified enzymes included their 4-methylumbelliferyl-substrate preferences, kinetic properties, inhibitor constants and thermal stability. On the basis of substrate specificity, kinetics and the results of inhibition studies, beta-hexosaminidases appear to differ from each other. HEX 1 and HEX 2 are similar to mammalian isoenzyme A and isoenzyme B, respectively. These findings represent the first report on the characterization of sperm proteins that are potentially involved in interactions with the egg in Insects.

Pathogenicity of Leucocytozoon caulleryi for specific pathogen-free laying hens

The pathogenicity of Leucocytozoon caulleryi against specific-pathogen-free laying hens was investigated. Many large schizonts (second-generation schizonts) of L. caulleryi were seen in the ovary and oviducts of chickens. Edema and pressure atrophy of the adjacent tissues were associated with these schizonts. The eggshell-secreting portion of the uterus exhibited the most severe damage in the oviduct. This experiment reconfirms that L. caulleryi may stop egg production in laying hens, presumably as a result of damage to ovaries and oviducts.

Examination of hydroxyapatite filled 4-META/MMA-TBB adhesive bone cement in vitro and in vivo environment

Bone response to hydroxyapatite (HA) fillers in the cured-4-methacryloyloxye-thyl trimellitate anhydride (4-META)/methyl methacrylate (MMA)-tri-n-butyl borane (TBB) adhesive bone cement was examined mechanically and histologically. A two-component system, consisting of powder and liquid, was formulated. The liquid portion was 5% 4-META dissolved in MMA and TBB; the powder was composed of 50 wt% poly (MMA) (PMMA) and 50 wt% dense HA fillers. The results indicated that the tensile strength decreased with the increase of HA filler size. The bone-bonding behavior of the improved cement was examined by optical microscopy and scanning electron microscopy. Seventy-two implants in six dogs for up to 24 weeks showed 4-META cement filled with HA was stable in the cement-bone interface. Histologic examinations showed that the exposed HA particles at the surface of the cured cement were generally associated with intimate attachment to bone without fibrous tissue, as well as interdigitation of cement to bone. The results suggest the importance of HA fillers in inducing bone apposition that improves cement binding to bone for long-term stability, thereby complementing rapid initial bone fixation of the cement.

Reassessment of long-term use of dense HA as dental implant: case report

Dense hydroxyapatite (HA) is widely believed to be unsuitable for clinical use as dental implants due to its poor mechanical properties, although it has excellent biocompatibility and is chemically stable and nonresorbable in vivo. However, the case in this article is one in which the patient's dense HA implants are still stable and in good functional condition 16.5 years after he received four pieces of a one-piece dense HA implant in both sides of his lower molar regions. Furthermore, almost no radiolucency is evident along the root portions of the implant sites in the bone. These findings imply that dense HA can be clinically useful and should be reevaluated as a dental implant material.

Metachronous triple cancers of the sigmoid colon, stomach, and esophagus: report of a case

We report herein an unusual case of metachronous triple cancers of the sigmoid colon, stomach, and esophagus. A 60-year-old man was initially admitted to our hospital for investigation of occult fecal blood. This was found to be caused by sigmoid colon cancer which was resected in July 1985 (T3, N0, M0; Stage II). A follow-up endoscopy performed in 1990 showed early gastric cancer, and a gastrectomy was performed in August 1990 (Tis, N0, M0; Stage 0). Another endoscopic examination performed as follow-up in 1993 revealed early cancer of the remnant stomach, and all the remnant stomach was surgically resected in March 1993 (Tis, N0, M0; Stage 0). He presented again in December 1996, complaining of discomfort in the chest which was found to be caused by cancer of the middle thoracic esophagus. Although surgery was considered necessary, the patient refused to undergo any further operations. Instead, radiation was administered from January 1997. An endoscopy after the completion of radiotherapy confirmed that the cancer had almost disappeared; however, it started to grow again from the beginning of 1998. He was hospitalized due to esophageal stenosis in April 1998, and died of carcinomatous cachexia in September of the same year.

Localization of biologically uncommon D-beta-aspartate-containing alphaA-crystallin in human eye lens

PURPOSE

Previous studies demonstrated that the Asp-151 residue of alphaA-crystallin from human eye lens is stereoinverted to the biologically uncommon D-isomer and isomerized to the beta-aspartyl residue (isoaspartate) with age. To detect the locality of the D-beta-Asp-containing peptide in aged human lens, we prepared a highly specific antibody against peptide Gly-Leu-D-beta-Asp-Ala-Thr which corresponds to positions 149-153 of human alphaA-crystallin using peptide Gly-Leu-D-beta-Asp-Ala-Thr-Gly-Leu-D-beta-Asp-Ala-Thr-Gly-Leu-D-beta- Asp-Ala-Thr (designated peptide 3R) as an immunogen.

METHODS

Peptide 3R was synthesized with F-moc (9-fluorenylmethoxycarbonyl) solid phase chemistry and then the peptide was immunized in rabbits to generate antibody against peptide 3R. The antibody in rabbit serum was purified by affinity chromatography using peptide 3R and bovine alphaA-crystallin as ligands. The specificity and titer of antibody were checked by ELISA assay. We synthesized four kinds of peptide T18 (IQTGLDATHAER; corresponding to the amino acid sequences 146-157 in human alphaA-crystallin) in which Asp-151 residues were normal L-alpha-Asp, abnormal D-alpha-Asp, L-beta-Asp, and D-beta-Asp, respectively. The specificity of antibody was confirmed by ELISA using these peptides and utilized in immunohistochemistry.

RESULTS

The antibody we prepared crossreacted specifically to D-beta-Asp-151-containing alphaA-crystallin. Immunohistochemical staining of human lens with the antibody demonstrated that D-beta-Asp-151-containing alphaA-crystallin was predominantly localized in the core of aged human lens.

CONCLUSIONS

The peptide 3R antibody clearly recognized the presence of racemized and isomerized Asp-151 in both protein solution and lens tissue obtained from aged human lens.

Lesions of bone and bone marrow in myeloid leukosis occurring naturally in adult broiler breeders

Lesions of bone and bone marrow in myeloid leukosis (ML) occurring naturally in adult broiler breeders were investigated pathologically. During gross examination, nodules and protrusions were commonly observed on the surface of the sternum, ribs, vertebrae, and synsacrum. The bone marrow of all the bones of the body was pale in color. Histologically, granulated myelocytes proliferated in the bone marrow of various bones and in the periosteum of the sternum, ribs, vertebrae, and synsacrum. The first proliferation of tumor cells occurred in the bone marrow of epiphysis. The myelocytes invaded through haversian and Volkmann's canals from the bone marrow to periosteal areas. Hematopoiesis was suppressed by marked proliferation of tumor cells in the bone marrow of the whole bone. Atrophy was also seen in the bones, including medullary bones of the chickens suffering from ML. Proliferation of myelocytes was seen in the bone marrow and periosteum of ossified cartilaginous rings of the trachea and larynx. Marked proliferation of myelocytes was seen in the dura mater of spinal cords, and it subsequently depressed the spinal cords. Bone formation with cartilage was seen in the periosteum of the sternum having marked proliferation of myelocytes in the bone marrow and periosteum. Ultrastructurally, tumor cells showed large nuclei and cytoplasm with large round electron-dense lysosomes. The virus particles were rarely detected in the cytoplasm of tumor cells. The polymerase chain reaction test of tumor samples showed positive for subgroup J avian leukosis virus. This study indicates that the myelocytes can invade through the compact bones to the periosteum in the sternum, ribs, vertebrae, synsarcum, and ossified cartilage of trachea and larynx having thinner compact bones. In addition, the periosteal osteogenesis with cartilage in the sternum may be reactive change against the bone atrophy because of the marked proliferation of myelocytes.

Neutral and acidic glycosphingolipids in glucocorticoid-induced cataract in chick lens

Administration of glucocorticoids induces transient cataract in 15-day-old chick embryos within 48 hr, and the opaque lens again becomes clear within the subsequent 48 hr. Oxidative stress is likely to be involved in the process of cataract formation, resulting in the appearance of numerous vacuoles around the perinuclear region. Chick lens contained low amounts of glycosphingolipids, which mainly consists of GM3, GD3, sialyl-LewisX gangliosides and glucosylceramide. Most lens gangliosides were immunohistochemically detected in lens epithelia, annular pads and developing fibers, but not in perinuclear and nuclear regions. Since cell surface gangliosides, for example GM3 and sialyl-LewisX gangliosides, are involved in cell adhesion, weak cell-to-cell interactions in the perinuclear and nuclear regions may allow vacuole formation in steroid-induced cataractogenesis.

Implication of glycolipids in lens fiber development

Mammalian lens contains Lewis(x), sialyl-Lewis(x) and alpha-galactosyl epitopes in neolactoseries glycosphingolipids. The expression of these three epitopes is not observed in lens epithelial cells, but is immunohistochemically detected in the inner cortical fibers and the lens nucleus. In embryonic chick lens, sialyl-Lewis(x)-containing gangliosides were also detected in the transitional zone and elongating lens fibers. Thus, the Lewis(x), sialyl-Lewis(x) and alpha- galactosyl epitopes may be associated with the differentiation and maturation of lens epithelial cells to lens fibers.

Differences in microstructural characteristics of dense HA and HA coating

Two implant types of hydroxyapatite (HA) currently are available for dental implants: dense HA-cemented titanium (Ti) and HA-coated. It has been shown in previous reports that there are differences in the chemical and mechanical stabilities between the dense HA and HA coated. The differences are thought to be due to structural differences between the two ceramic types. The aim of this study was to investigate the differences in microstructural characteristics of currently available dense HA and HA coated implants before implantation and at periods of 3 weeks and 10 months after implantation in canine bone. X-ray diffractometry, infrared analysis, transmission electron microscopy, and energy dispersive X-ray analysis were used. The dense HA is composed of crystal grains, with a well crystallized structure of HA, closely bound to each other and approximately 0.4-0.6 micron in size. Implantation did not change the original sintered structure of the dense HA. The HA coating was composed of an amorphous phase with a Ca/P ratio of 1.46 and a crystal phase consisting of oxyhydroxyapatite, tricalcium phosphate, tetracalcium phosphate, and CaO, with a Ca/P ratio of 1.57. In the amorphous phase, compared to other portions in the amorphous phase, there were some layers with lower atomic density and with no significant difference in Ca/P ratio. After implantation, the crystallization of super fine crystals of approximately 4-5 nm in thickness occurred in the amorphous phase, and with time it progressed and spread from the surface to the deeper portion of the HA coating. A Ca/P ratio of 1.58 in the crystallized portion was close to the ratio (1.60) in the dense HA, suggesting that the super fine crystals were HA. This crystallization cannot significantly decrease the solubility of the amorphous phase portion and poses risks of stress accumulation within the coating and a decrease of binding strength between the HA coating and the substrate.

Implication of glycolipids in lens fiber development

Mammalian lens contains Lewis(x), sialyl-Lewis(x) and alpha-galactosyl epitopes in neolactoseries glycosphingolipids. The expression of these three epitopes is not observed in lens epithelial cells, but is immunohistochemically detected in the inner cortical fibers and the lens nucleus. In embryonic chick lens, sialyl-Lewis(x)-containing gangliosides were also detected in the transitional zone and elongating lens fibers. Thus, the Lewis(x), sialyl-Lewis(x) and alpha- galactosyl epitopes may be associated with the differentiation and maturation of lens epithelial cells to lens fibers.

The process of physical weakening and dissolution of the HA-coated implant in bone and soft tissue

Hydroxyapatite (HA)-coated implants were developed to promote osseointegration of titanium implants and to overcome the mechanical drawbacks of solid HA implants. Although many clinical reports on the prognosis of HA-coated implants have reported high success rates, the risks of dissolution and weakening of the coating have been noted. We hypothesized that the chemical and mechanical stability of HA coating are affected by its microstructural characteristics. The present study investigates differences in the microstructures of available HA-coated implants, before and after implantation into the coxal bones of dogs for periods ranging from 3 weeks to 10 months and under the coxal periosteum of dogs for 10 months. The results of transmission electron microscopy and energy-dispersive x-ray analysis revealed that crystallization of super-fine HA crystals occurred in the amorphous phase of the HA coating and progressed over time. This crystallization weakens HA-coated implants by making the amorphous phase brittle, causing stress accumulation within the coating, and causing a decrease in the binding strength between the coating and the substrate. Furthermore, the HA coating dissolved in soft tissue. Dissolution started with the super-fine HA crystals in the crystallized portion that was originally part of the amorphous phase.

Expression of sialylated Lewisx gangliosides in cultured lens epithelial cells from rhesus monkey

Monkey and human lenses contain essentially the same glycosphingolipids, and Lewisx and sialylated Lewisx epitopes are expressed on the terminal structure of neolactotetraosylceramide. However, monolayer cultures of lens epithelial cells from rhesus monkey expressed gangliosides GM3, GD3 and a small amount of GM1, but not sialylated Lewisx epitopes. Eight-week-old cultures on various extracellular matrices resulted in morphological changes in lens epithelial cells. Monolayer of cells cultured on vitronectin or polylysine assembled into aggregates after 4 weeks of culture. Cells cultured on vitronectin expressed sialyl-Lewisx gangliosides and did not exhibit GD3. On collagens, fibronectin and laminin elongated cells were observed in cells cultured for 8 weeks. Thus, the interaction between cells and extracellular matrices influenced morphology and glycosphingolipid composition in lens epithelial cells.

Comparative push-out test of dense HA implants and HA-coated implants: findings in a canine study

Two types of hydroxyapatite (HA) implants have been developed: an HA-coated implant and a dense HA implant. For a longer in situ life span, the HA implant must remain chemically stable and possess high resistance to occlusal force. To determine which type of HA implant shows better durability, this comparative dog study was done to evaluate push-out test results of HA-coated implants and dense HA implants of approximately the same size after implantation in the mandibular and coxal bones for periods ranging from 3 weeks to 10 months. The findings revealed that for the mandibular implants, the push-out values of HA-coated implants were significantly higher than those of dense HA implants at 2 and 4 months after implantation, with significance levels of p < .001 and p < 0.05, respectively. However, there was no significant difference between the two implant types at 10 months. As for the coxal implants, no significant differences were noted for any period. Furthermore, the ratio of push-out values of the dense HA implants to those of the HA-coated implants situated in the same position bilaterally in each bone of the body for each implantation period rose with the passage of time, especially in the mandible. In the mandibular implants, the correlation coefficient of the relationship between the ratio and duration of implantation was highly significant (p < 0.001). Push-out testing caused detachment of the surface portion of the HA coating that was bound to the dense bone from the HA-coated implant at 2, 4, and 10 months after implantation. Furthermore, at 10 months the HA-coated layer in the wide areas of the implants had completely detached from the metal substrate, in contrast to the dense HA implants, which remained durable throughout the test period.

Localization of LewisX, sialyl-LewisX and alpha-galactosyl epitopes on glycosphingolipids in lens tissues

Mammalian lens contains several neutral and acidic glycosphingolipids, the core structures of which are ganglio-, neolacto-, globo-, and isoglobo-series sugar chains. Old World monkey lens shows glycosphingolipid compositions similar to those of human cataractous lens, in particular the presence of Lewisxand sialyl-Lewisxepitopes and the absence of alpha-galactosyl epitope. Dog and pig lenses contain globotriaosylceramide and the sialyl-Lewisxcontaining neolactotetraosylceramide, respectively, which were found in primate lens, together with the alpha-galactosyl epitope containing neolactotetraosylceramide. Thin-layer chromatography immunostaining revealed the enrichment of some neolacto-series glycosphingolipids in the cortical and nuclear fibers, but not in lens epithelia, of dog, pig, and Japanese monkey lenses. Immunohistochemical studies confirmed the expression of Lewisx, sialyl-Lewisx, and alpha-galactosyl epitopes in the inner cortical and nuclear fibers, in association with the differentiation and maturation of lens epithelial cells to lens fibers. Glycobiological approaches thus suggested that some neolacto-series glycosphingolipids are involved in lens fiber development, in which the physiological roles of the alpha-galactosyl epitope are evolutionarily replaced by the Lewisxand sialyl-Lewisxepitopes in Old World monkeys and humans.

Microstructural changes in bone of HA-coated implants

In our previous comparative push-out test of HA-coated implants and dense HA implants in dog bone, the ratio of the push-out value of the HA-coated implant to that of the dense HA implant decreased with time due to weakening of the HA coating as compared to the dense, more durable HA. The aim of this study was to investigate by histological examination of HA-coated implants in dog bone, using TEM, how this weakening of the HA coating occurs. The HA coating before implantation is composed of an amorphous glassy phase and a crystal phase scattered within the glassy phase. After implantation, the crystal phase remained almost unchanged. However, in the glassy phase, crystallization occurred and progressed with time. By 3 weeks after implantation, this crystallization already had started in the surface portion of the HA coating where it was covered by bone and also where it still touched the soft tissue. By 10 months, the crystallization had progressed to the deeper portion of the HA coating and had expanded to most of the glassy phase except for the narrow portions along the substrate-coating interface. These findings suggest that a progression of crystallization in the glassy phase causes stress accumulation within the HA coating, especially in the interface between the HA coating and the substrate, and that this stress accumulation results in a weakening of the HA-coated implant.

Bone formation on HA implants: a commentary

The present paper reviews bone formation on dense hydroxyapatite (HA) implants. Calcification of bone matrix formed on HA is different in areas where collagen fibers are dense and scattered with matrix vesicles than in those interfacial layers containing few or no collagen fibers and matrix vesicles. Calcification of collagen-coated areas begins with crystallization within the matrix vesicles. In contrast, calcification of the interfacial layer is initiated by epitaxial crystal growth on the HA. Crystallization within the matrix vesicles near the HA and those on the HA start simultaneously. Calcification of the interfacial layer is the most important feature of HA as a biomaterial. Such calcification is never observed on titanium implants. The recent postulation that the rate of bone formation on calcium-phosphate (CP) ceramics correlates with the solubility of CP ceramics is improbable, as in vitro immersion tests have been unable to establish correlation between osteoblast differentiation and the solubility of the CP ceramics. With regard to HA-plasma spray-coated implants, future research should focus on the purity of HA and the structure of the ceramics in order to increase the in vivo chemical and mechanical durability of HA coating.

A protein kinase inhibitor H-7 induces process extrusion in fetal rat thyroid C-cells in vitro

Calcitonin-producing cells (C-cells) are endocrine cells derived from the neural crest. We examined the effects of three types of protein kinase inhibitors on the induction of neuronal phenotypes in the rat thyroid C-cells in vitro. In a primary culture of 16-day-old fetal rat thyroid glands, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7, 25-75 microM) induced both process extrusion and expression of highly polysialylated neural cell adhesion molecule (NCAM) in the C-cells. These effects of H-7 were completely prevented by okadaic acid, a potent protein phosphatase inhibitor. In contrast to H-7, selective inhibitors for cyclic nucleotide-dependent protein kinases such as N-(2-guanidinoethyl)-5-isoquinolinesulfonamide hydrochloride (HA1004, 25-200 microM) and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89, 0.25-20 microM) failed to induce process extrusion or the expression of highly polysialylated NCAM in fetal rat C-cells. In cultured C-cells of adult origin, H-7 failed to induce marked process elongation or the expression of highly polysialylated NCAM. These results suggest that the morphological plasticity of the fetal C-cells depends upon the degree of phosphorylation of some proteins, and that the plasticity of adult C-cells are more restricted than that of fetal origin.

Developmental changes in carbohydrate antigens in embryonic rat lens

The functions of glycosphingolipids, especially those containing the alpha-galactosyl epitope, were investigated during the development and differentiation of rat lens. Glycosphingolipids in embryonic lens tissue were mainly composed of neolacto-series glycosphingolipids and sialic acid-containing ganglio-series gangliosides GM3 and GD3. These glycosphingolipids and gangliosides were widely expressed on cell membranes in the lens vesicle and the elongating lens fibers. In particular, the expression of neolacto-series glycosphingolipids with the alpha-galactosyl epitope was found to be associated with the differentiation and interaction of lens fibers. Glycoproteins with the alpha-galactosyl epitope was also involved in the elongation of lens fibers. The expression of the glycoproteins was highly specific in elongating lens fibers when these were examined in head sections obtained at various embryonic stages. Thus, the alpha-galactosyl epitope on glycosphingolipids and glycoproteins appears to be associated with the differentiation and elongation of lens fibers in the rat. Evolution-related changes in the expression of carbohydrate antigens are also discussed in relation to the development and cell-to-cell interaction of lens fibers in mammals.

Gene expression in skin tumors induced in hairless mice by chronic exposure to ultraviolet B irradiation

We investigated the expressions of c-Ha-ras, c-jun, c-fos, c-myc genes and p53 protein in the development of skin tumors induced by chronic exposure to UVB without a photosensitizer using hairless mice. When mice were exposed to UVB at a dose of 2 kJ/m2 three times a week, increased c-Ha-ras and c-myc transcripts were detected after only 5 weeks of exposure, while no tumor appeared on the exposed skin. The increase in gene expression continued until 25 weeks, when tumors, identified pathologically as mainly squamous cell carcinomas (SCC), developed in the dorsal skin. In these SCC, overexpression of c-fos mRNA was also observed along with the increases in c-Ha-ras and c-myc. A single dose of UVB (2 kJ/m2) applied to the backs of hairless mice transiently induced overexpression of the early event genes c-fos, c-jun and c-myc, but not c-Ha-ras, in the exposed area of skin. Accumulation of p53 protein was determined by Western blotting analysis or immunohistochemistry using monoclonal antibodies PAb 240 or 246, which recognize mutant or wild type, respectively. In the SCC, a mutant p53 protein accumulated in the cytoplasm and nucleus. After single-dose irradiation, the increased wild-type p53 protein was observed in the nuclei of epidermal cells. The present results suggest that overexpression of the c-fos, c-myc and c-Ha-ras genes, and the mutational changes in p53 protein might be associated with skin photocarcinogenesis. Moreover, overexpression of the c-Ha-ras and c-myc genes might be an early event in the development of UVB-induced skin tumors in mice.

Developmental change in expression of highly polysialylated neural cell adhesion molecule in C-cells in rat thyroid gland

The expression of the neural cell adhesion molecule (NCAM), highly polysialylated NCAM, and E-cadherin was immunohistochemically studied in the calcitonin-producing cells (C-cells) of developing and adult rat thyroid glands of varying ages. In fetal and neonatal rat thyroids, almost all the C-cells displayed immunoreactivity for highly polysialylated NCAM, whereas most of the follicular cells were negative. The highly polysialylated NCAM-positive C-cells markedly decreased in number between 5 and 14 days after birth. From day 14 onward, immunoreactivity for highly polysialylated NCAM was almost negative in thyroid glands. On the other hand, the expression of immunoreactivity for NCAM peptide persisted in thyroidal C-cells throughout the life span. These results suggest that conversion of the highly polysialylated NCAM into a less sialylated form occurs in the thyroid C-cells between postnatal days 5 and 14. Intense immunoreactivity for E-cadherin was observed in the entire cell surfaces of all the C-cells and follicular cells in the rats of all ages tested. In the course of thyroid organogenesis, C-cells transiently form a cell mass, an ultimobranchial body, which is fated to disappear as the C-cells migrate diffusely into the thyroid. The duration of the polysialic acid expression in the C-cell surfaces appears to coincide with the period of C-cell migration. It is possible that the expression of highly polysialylated NCAM allows the C-cells to migrate into the thyroid by reducing the cell-to-cell adhesion of C-cells with adjacent C-cells and/or with the surrounding follicular cells.

Identification and synthetic pathway of sialyl-Lewis(x)-containing neolacto-series gangliosides in lens tissues. 2. Enzymatic synthesis of sialyl-Lewis(x) gangliosides in monkey and rat lenses

In Japanese monkey lenses, 3H-labeled fucose and N-acetylneuraminic acid were enzymatically transferred to neolactotetraosylceramide (nLc4) and III 3 FucnLc4, respectively, suggesting the presence of a synthetic pathway of IV3 NeuAcIII3 FucnLc4 via III3 FucnLc4 in monkey lenses. Six rat strains, Wistar, Sprague-Dawley and pigmented strains, contained sialyl-Lewis(x) gangliosides in non-cataractous lenses in a strain-specific manner. Glycosyltransferase assay revealed that the transfer of 3H-labeled fucose to nLc4 occurred in all the strains, but that the transfer of 3H-labeled N-acetylneuraminic acid to III3 FucnLc4 was strain-specific. These results suggested that sialyl-Lewis(x) gangliosides were generally synthesized from neolactotetraosylceramide via Lewis(x) glycolipid (III3 FucnLc4) in lens tissues, differing from other tissues. Combining our results, we propose two synthetic pathways of sialyl-Le(x)- containing neolacto-series gangliosides and A-pathway ganglio-series gangliosides in human senile cataractous lens: one to sialyl-Lewis(x) gangliosides from nLc4 via Lewis(x) glycolipid, and the other to GD1a from GM3, via GM2 and GM1.

Adhesive improvement of the mechanical properties of a dense HA-cemented Ti dental implant

We have been using dense, pure hydroxyapatite (HA) dental implants for the last 15 years and results have shown that dense HA is a chemically stable material with acceptable mechanical properties. However, due to HA's physical characteristics, particularly its brittleness, there is the risk that the implant will fail if the subsequent bone binding comprises less than one half of the root portion. To ensure greater implant success, a new cementing method has been developed that uses methacrylates for the bonding of the dense HA outer shell to the titanium (Ti) inner cylinder in a two-piece HA-cemented Ti implant. Mechanical property tests were conducted to compare the HA-cemented Ti implant bonded with this new acrylic cement with existing commercially available HA-cemented Ti implants bonded with a triethyleneglycol dimethacrylate (TEGDMA)-bisphenol-A diglycidyl ether (BisGMA compound). The vertical and horizontal compressive strength of this improved implant was respectively 3.4 and 6.1 times greater than the commercial implants. This increased strength of new acrylic cement is due to its ability to compensate for shrinkage that affects adhesion during curing, thereby providing stronger bonding.

Delay method of implantation enhances implant-bone binding: a comparison with the conventional method

This report compares the conventional and delay methods of implantation, evaluating the bone formation around a dense apatite implant. In the conventional method, the implant is placed immediately after the cavity is prepared. In the delay technique, the implant is placed 2 weeks after preparation. This study found that many new thin trabeculae and capillaries formed around the cavity during the delay period, while none had formed at the time of implantation using the conventional method. The delay method showed earlier and wider bone formation, and less surrounding fibrous encapsulation. These results indicate that the delay technique can be an efficient method for establishing good bone binding.

Identification and synthetic pathway of sialyl-Lewisx-containing neolacto-series gangliosides in lens tissues. 1. Characterization of gangliosides in human senile cataractous lens

Human lens accumulates gangliosides in association with aging and senile cataract progression. In this study we purified and characterized five major gangliosides in human cataractous lenses. Structural analyses and immunological studies revealed the presence of ganglio-series gangliosides, GM3, GM2, GM1 and GD1a, and a sialyl-Lewisx-containing neolacto-series ganglioside, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1ceramide (IV3NeuAcIII3FucnLc4). Slow-moving gangliosides, although minor components, were also found to have sialyl-Lewisx-related structures, based on anti-Lewisx antiserum binding to their asialo forms. However, sialyl-paragloboside, a possible precursor of the sialyl-Lewisx ganglioside, was not identified.

Differential distribution of gangliosides in adult rat ovary during the oestrous cycle

Gangliosides are ubiquitous membrane components in mammalian cells and are suggested to play important roles in various cell functions, such as cell-cell recognition, differentiation and transmembrane signalling. Rat ovary contained GM3, GD3 and GD1a as major gangliosides, and GM1 as a minor one. In order to study their distribution in the rat ovary and its possible changes during the oestrous cycle, frozen sections were stained with specific monoclonal antibodies against 11 ganglio-series gangliosides including those mentioned above. GM3, GM1 and GD1a were expressed in a spatio-temporally different manner during the oestrous cycle, but GD3 and other gangliosides were not immunohistochemically detected. In primary and secondary follicles, GM3, GM1 and GD1a were expressed in theca cells, but not in granulosa cells. The oocyte in primary, but not secondary, follicles was positive to the anti-GD1a antibody. In Graafian follicles, GM1 and GD1a were similarly expressed as in secondary follicles, however, the expression of GM3 spread gradually from theca cells to granulosa cells. In early Graafian follicles, only GM3 was expressed to a detectable extent from the outer part of the granulosa layer to the inner part. Shortly before ovulation, all granulosa cells and cumulus cells became positive to anti-GM3 antibody. After ovulation, differential distribution of GM3, GM1 and GD1a was also observed in luteal cells. GD1a was localized in thread-like structures, while GM3 was distributed throughout the cytoplasm, but not in the nucleus. GM1 was localized only in the plasma membrane and/or its close vicinity. Other ganglio-series gangliosides, including GD3, were not detected to an appreciable extent in the ovaries by immunohistochemistry.

Localization of neutral and acidic glycosphingolipids in rat lens

Rat lens was found to contain several neutral and acidic glycosphingolipids in lens epithelia, cortex and nucleus, and showed developmental changes in their content and localization. TLC-immunostaining of gangliosides revealed the enrichment of some ganglio-series gangliosides (GM3, GM1, GD3 and GD1b) in lens epithelia and the presence of GM3 and GD3 in the lens nucleus. Immunohistochemical studies confirmed the distribution of GM3 and GM1 in anterior lens epithelial cells and the cortex, with expression decreasing toward the lens nucleus. Immunoreaction to GD3 was more intense in the lens nucleus than in epithelial cells. In contrast, the expression of neolacto-series glycosphingolipids was restricted to the lens nucleus. In order to investigate the pathological changes of glycosphingolipids in cataract, galactose-induced cataractous lenses were examined. However, no significant changes were observed in the content and composition of glycosphingolipids. In addition, Lewisx epitopes found in human cataractous lenses were not detected in the cataractous lenses of galactosaemic rats and hereditary cataractous Emory mice.

Age-related changes in ganglioside composition in human lens

We previously reported that human lens accumulates gangliosides in association with aging and senile cataract progression. Structural analysis revealed that gangliosides in human cataractous lenses were composed of ganglio-series gangliosides, such as GM3, GM2, GM1 and GD1a, and sialyl-Lewisx-containing neolacto-series gangliosides. Although Lewisx-containing neolacto-series glycolipid was found to accumulate in association with aging and cataract progression, the sialyl-Lewisx gangliosides did not show much accumulation in individual lenses from subjects between 16 and 80 years old. The content of sialyl-Lewisx gangliosides was about two to four times higher than that of Lewisx glycolipids, suggesting the possibility that the increase in Le(x) glycolipid is partly due to the desialylation of sialyl-Le(x) gangliosides. On the other hand, the expression of ganglio-series gangliosides increased in an age-related manner. Thus, age-related changes in lens glycolipids may modify the cell-to-cell interaction induced by cell surface sugar chains, leading to the initiation and progression of cataract.

Characterization of neutral glycosphingolipids in rat lens

Neutral glycosphingolipids were purified from non-cataractous lenses of Sprague-Dawley rats by a combination of solvent extraction, Folch's partition, and column chromatography using DEAE-Sephadex and Iatrobeads. Six major GSLs from monohexosylceramide to pentahexosylceramide were identified by sugar composition analysis, methylation analysis and glycosidase digestion. Structural relationships among the six neutral glycosphingolipids revealed metabolic pathways leading to the synthesis of Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1 ceramide (IV3Gal alpha nLc4), instead of a Lewis(x) glycolipid (Gal beta 1- 4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1 ceramide, III3FucnLc4), from neolactotetraosylceramide (nLc4), together with isoglobotriaosylceramide (iGb3). The alpha-galactosyl epitope, Gal alpha 1-3Gal-R, is evolutionarily conserved in many types of cells of non-primate mammals, prosimians and New World monkeys, but not in those of Old World monkeys or humans. This evolution-related difference in carbohydrate epitopes suggests different cell-to-cell attachments, which may be mediated through cell surface glycosphingolipids, between rat and human lenses.

A matched-pair longitudinal study on the relationship between maternal smoking and head circumference of newborns

The relationship between maternal smoking and the head circumference of newborns were analyzed using a matched-pair longitudinal method. For the study, data was collected from Japanese primiparas in Aichi, Japan. Forty-seven smoking and nonsmoking mothers were matched using multivariate caliper matching for birth weight and gender for their newborns, and gestational period and age for the gravidas. Significantly smaller head circumferences of the newborns from the smoking mothers were observed.

Comparative study of glycosphingolipid composition in mammalian lenses

The carbohydrate epitope Gal alpha 1-3Gal-R (alpha-galactosyl epitope), which is detectable by its binding with Bandeiraea simplicifolia-IB4 lectin, was found in glycosphingolipids (GSLs), both neutral and acidic (gangliosides), from lens tissues of non-primate mammals, but not in those of human senile cataracts and Old World monkeys. Instead, human cataractous and Old World monkey non-cataractous lenses expressed Lewisx (Le(x)) epitopes (Gal beta 1-4(Fuc alpha 1-3)GlcNAc-R) in neutral GSLs. Sialylated Le(x) epitopes were found in rat and pig lenses as well as in human and Old World monkey lenses. Ganglio-series gangliosides, consisting mainly of GM3, GM1, GD1a and GD3, were detected in a species-specific fashion. On the other hand, alpha-galactosyl epitopes were expressed in lens tissues only in water-insoluble proteins of non-primate mammals, but Le(x) and sialylated Le(x) epitopes were not detectable in lens proteins. Among the several mammalian lenses examined, humans and Old World monkeys showed similar GSL compositions, in particular the presence of Le(x) and sialylated Le(x) epitopes and the absence of alpha-galactosyl epitopes, in lens tissue.

The delay method: a new surgical technique for enhancing the bone-binding capability of HAP implants to bone surrounding implant cavity preparations

To confirm the efficacy of a new apatite-implantation technique, in vivo research was undertaken on 12 dogs. The project was designed to determine the time-dependent effects on alveolar tissues surrounding implant cavity preparations without implantation in bone. In addition, a group of hydroxyapatite (HAP) implants was placed immediately after cavity preparation (conventional method). A second group was placed after a delay of 2 weeks (delay method). Hemorrhagic infiltration occurred within the cavity and into the surrounding fatty marrow, a phenomenon attributed to cavity preparation. Subsequent to absorption of infiltrated blood cells into the surrounding marrow, fibrous tissue was formed, followed by osseous formation initiated by the original bone. Formation of newly formed, thin trabeculae reached a peak at 14 days. Most of the original marrow near the cavity, where few trabeculae were originally present, was transformed into thin trabecular-forming areas. In addition, sinusoidal capillaries and hematopoiesis were formed at the site. At 30 days, the number of new trabeculae and sinusoidal capillaries formed decreased, and adipose cells began to appear. These results indicate that tissue surrounding the prepared cavity was centrally activated at 14 days, and that this activation may be beneficial in the biologic ability of an apatite implant to advantageously affect bone binding and chemical bonding activity. It is concluded that bone formation was faster and wider around implants placed by the delay method than that surrounding conventionally placed implants. These results indicate that more efficient bone formation around implants was encouraged by bone activation stimulated during the 14 day delay period.

Glycosphingolipids in cultured lens epithelial cells from dog and rhesus monkey

Vertebrate lens tissues contain several species of acidic and neutral glycosphingolipids in relatively high amounts. However, the epithelia with capsule from dog and rhesus monkey lenses had a simpler composition and lower content of glycosphingolipids than whole lenses. Gangliosides and neutral glycosphingolipids in monolayer cultures of lens epithelial cells were also different from those in whole lenses. Although alpha-galactosyl (Gal alpha 1-3Gal-R) or Lewis(x) (Gal beta 1-4[Fuc alpha 1-3]GlcNAc-R) epitopes were found in glycosphingolipids from whole lenses, they were not detected in those from monolayer cultures of dog and rhesus monkey lens cells. In addition, significant changes in ganglio-series gangliosides were induced in monolayer cultures of both cells, where GM3 and GD3 were predominant. Immunofluorescence study revealed a characteristic distribution of cell surface gangliosides in confluent monolayers. These findings suggest that glycosphingolipid synthesis in lens epithelia is intrinsically different from that in cortical and nuclear fibres, and that the expression of Lewis(x) and alpha-galactosyl epitopes in glycosphingolipids appears to be associated with the differentiation of epithelial cells to fibres.

A histologic comparison of the functional loading capacity of an occluded dense apatite implant and the natural dentition

A histologic comparison of the functional loading capacity of an occluded dense apatite implant and the natural dentition at a ratio of one implant to three natural teeth was carried out on six monkeys. Single implants were placed in the maxillary left second molar and mandibular right second molar of each monkey. Four months later, the vertical dimension of occlusion was raised at the contacting areas between the implant and the connected first, second, and third opposing molar teeth by placing metal crowns on them. The three connected molars gradually intruded over time, whereas the supporting bone of the mandibular and maxillary implants showed no abnormalities and was able to bear the load because of thickening and remodeling of the surrounding bone.

Expression of highly polysialylated neural cell adhesion molecule in calcitonin-producing cells

Calcitonin-producing cells are endocrine derivatives of the neural crest and have several neuron-like properties. Expression of the neural cell adhesion molecule in calcitonin-producing cells was examined using two types of antibodies to neural cell adhesion molecule: monoclonal antibody 12E3 recognizes the polysialic acid portion of highly polysialylated neural cell adhesion molecule, and monoclonal antibody AF11 and polyclonal antiserum react with the polypeptide portion common to three major isoforms of neural cell adhesion molecule. An immunohistochemical study revealed that highly polysialylated neural cell adhesion molecule was expressed both in fetal rat thyroidal calcitonin-producing cells and in a calcitonin-producing cell line, rMTC 6-23, established from explantable neoplasm of rat calcitonin-producing cells. The neural cell adhesion molecule in the rMTC 6-23 cells was further characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis. Two anti-neural cell adhesion molecule monoclonal antibodies, 12E3 and AF11, revealed a broad positive band around 200,000-250,000 mol. wt in solubilized proteins. When the polysialic acids were eliminated by neuraminidase treatment, the immunoreactivity to monoclonal antibody 12E3 was completely abolished, and core polypeptide corresponding to neural cell adhesion molecule with a molecular weight of 120,000 was detected by monoclonal antibody AF11. These results suggest that cells of the calcitonin-producing cell line express on their surfaces highly polysialylated 120,000 mol. wt form of neural cell adhesion molecule polypeptide.

Characterization of neutral glycosphingolipids in human cataractous lens

Neutral glycosphingolipids were purified from human senile cataractous lenses by a combination of solvent extraction, Folch's partition, acetylation, and column chromatography using DEAE-Sephadex and Iatrobeads. Six major glycosphingolipids (A-F) from monohexosylceramide to pentahexosylceramide were identified by sugar composition analysis, methylation analysis, secondary ion-mass spectrometry, glycosidase digestion, and chromium trioxide oxidation. Their structures suggested that they were closely related in their metabolism: their sugar chains were in sequence and their ceramide moieties were similarly composed, namely C16:0 and C24:1 constituted most of the fatty acids, and long-chain base components were mostly C18-dihydrosphingosine with a small portion of C18-sphingosine. The sugar chains implied two pathways branching from lactosylceramide: one to globotriaosylceramide and the other to lactotriaosylceramide, which leads to the production of Le(x) glycolipid via neolacto type 2 core chain.

[Examination of confusion loci in acquired color vision deficiency with surface color]

Miscellaneous color vision tests were performed on 66 eyes in 46 acquired blue-yellow deficiency cases, in which the deficiency resembled congenital tritanopia. The confusion loci converged at a point on the short wavelength side of the spectrum in central chorioretinopathy, diabetic retinopathy, branch retinal vein occlusion, retinal pigmentary degeneration, and macular degeneration. However, the confusion loci of glaucoma differed from those of the other 5 diseases of the retina. They crossed the purple boundary, showing a unique tendency among the diseases exhibiting acquired blue-yellow deficiency. In these diseases, except in chorioretinopathy, no correlation was observed between visual acuity, visual field and color confusion.

Clinical evaluation of two-piece apatite dental implants in 189 cases

A two-piece apatite implant composed of a titanium abutment and a titanium tubular root portion cemented to an outer dense hydroxyapatite (D-HAP) tubular shell by resin cement has been authorized as High Advanced Medical Technology (H.M.A.T.) and applied since December 1987. We will show the success rate and the evaluation of the implants applied through May 1992. A successful implant was considered as one that provides functional comfort with no mobility and the absence of surrounding mucosal inflammation. The number of implants applied during the last 4.5 years was 810 pieces in 189 cases with an overall success rate of 92.5% for the 704 implants with abutment. The extirpation rate has no clear linear association with the duration of the implant or with the patient's age. Most of the extirpations resulted from cases where the patient used a provisional denture during the bone healing period, the time between implantation and abutment cementation. Extirpation rate of implant was high in cases using large maxillary provisional dentures with ten or more missing teeth. It is believed that all implant cases in which large dentures were used frequently contributed to the extirpation. These observations led us to suggest that provisional dentures may be harmful to the implant. When we shifted from the traditional method to the Delay Method 2.5 years ago, no incidence of extirpation was experienced in the mandible, even with the use of provisional dentures. In the maxilla, the Delay Method proved to be effective without the provisional denture. However, the results of the Delay Method with provisional dentures remains to be evaluated. The reason is that too few cases were encountered with large missing teeth to suffice for our observation. This Delay Method (named by us) consists of delaying the insertion of the implant for approximately 2 months after the first socket preparation, until the bone tissue activity has risen. After some adjustment in the prepared socket, the implant is then inserted during the second surgical procedure. We therefore consider this method of potential benefit over the traditional method.

Tissue response of apatite-filled resin cement and titanium-reinforced apatite dental implants in dogs

Abutment and root portion divided two-piece dental implants were designed to modify the one-piece dense hydroxyapatite (D-HAP) implant. The initial placement of the root portion endosseously ensured an aseptic environment and physical stability for the implant during the bone healing period. The outer D-HAP shell of the root portion was fortified by an inner titanium cylinder and cemented with an adhesive resin cement containing 4-methacryloyoxyethyl trimellitate anhydride (4-META) and reinforced by fine apatite filler. Upon attaining integration of the bone and implant, the abutment was screwed and fixed into the screw hole of the root portion. The tissue response of both the apatite-filled resin cement and root portion of the two-piece implant was studied by animal canine experiments. Light and electron microscopic examination of specimens taken from experimental animal tissue showed bone contacted directly not only the exposed apatite filler at the surface of the apatite-filled resin cement, but also the resin portion. These findings of direct bone contact suggested that the tissue response of apatite-filled resin cement was approximately similar to the usual D-HAP. Because most of the surface of the outer D-HAP shell of the root portion came in contact with bone, it prevented the deposition of contamination on the D-HAP surface during the manufacturing procedures of the root portion.

Neuronal ganglioside increases dependent on the neuron--glia interaction in primary culture

Dissociated neuronal cells from rat embryonic hemispheres were cultivated on astroglial layers. The increase in ganglioside content of the cocultures was more rapid than that of neuronal cultures seeded on polylysine surfaces for the first 24 h, and the extent of the increase was greater 7 days after inoculation, probably because of interaction between the preformed astroglial layers and the neuronal cells in vitro. The promoted expression of the a-pathway gangliosides, GM1 and GD1a, was recognized by TLC and the increase in GM1 was immunologically ascertained. The incorporation of 3H-labeled N-acetyl-D-mannosamine into GD3 and b-series gangliosides was elevated for the first 24 h. However, cocultures in which there was no contact between neuronal cells and the astroglial sheet showed no appreciable increase in incorporation. Thus, cell surface changes were induced at the membrane glycolipid level in the neuronal cells by contact with astroglial layers. The synthesis and expression of neuronal gangliosides are discussed in relation to the onset of neuron--glia interaction.

Senile cataract-related accumulation of Lewis(x) glycolipid in human lens

A glycosphingolipid that reacted positively to anti-stage-specific embryonic antigen-1 (SSEA-1) antiserum accumulated in human lens in association with aging and senile cataract formation. Since this antiserum recognizes Lewis(x) (Le(x)) structure, Gal beta 1-4(Fuc alpha 1-3)GlcNAc-, which is a typical tumor-associated and differentiation-related saccharide chain, the lens glycolipid was predicted to be a Lex antigen. The glycolipid purified from cataractous lens tissues was indeed a Lex glycolipid, Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1- 4Glc beta 1-1 ceramide. Enhanced expression of the Lex glycolipid may affect the organization of lens plasma membranes through Le(x)-Le(x) interactions, as suggested for compaction in mouse preimplantation embryos and embryonic teratocarcinomas, resulting in lens opacification, namely cataract.