[Analysis of the profile of CD4+ cells in Behçet's disease]

The cell-mediated immune response and disorders of the cytokine-producing cells play an important role in the pathogenic mechanisms of Behçet's disease. Recently, CD4+ T helper cells have been categorized into at least two distinct subsets based on their profiles of cytokine production. We analyzed the number of interleukin (IL)-2 producing type 1 helper T (Th1) cells and IL-4 producing Th2 cells from 22 patients (male: 12, female: 10) with Behçet's disease and 19 normal controls (male: 9) by flow cytometric analysis. The patients with Behçet's disease were categorized into two groups by the activity of ocular inflammation; one group comprised the active cases (13 patients) and the other the inactive cases (9 patients). Peripheral blood mononuclear cells (PBMCs) from patients and normal controls were stimulated with immobilized anti-CD3 mAb for 6 hours and immunostained with anti IL-2 and anti IL-4 mAbs followed by fluorescein isothiocyanate (FITC) conjugated 2nd Abs. The number of IL-2 producing CD4+ cells in Behçet's disease patients with active uveoretinitis was significantly higher than that from both inactive cases (p < 0.005) and controls (p < 0.01). In contrast, the number of IL-4 producing CD4+ cells showed no significant difference among the groups. These results may indicate that Th1 cells play an important role in the immunopathogenesis of ocular inflammation of Behçet's disease. Thus, analysis of Th subsets in Behçet's disease may be useful for management of the disease.

Membrane skeletons in avian erythrocytes as revealed by the quick-freezing and deep-etching method

Ultrastructure of chicken erythrocytes were examined by the quick-freezing and deep-etching (QF-DE) method. Some erythrocytes were fixed with paraformaldehyde and prepared with erythrocyte-splitting method or saponin treatment to remove soluble proteins before quick-freezing. Others were prepared in the cytosol buffer with the erythrocyte-splitting method to obtain natural state of cytoskeletons. Non-expanding membrane skeletons were highly condensed on the cytoplasmic side of lipid membrane in the paraformaldehyde-fixed specimens. Under unilateral extension of the specimens, long stretched filaments were connected alternately with condensed filamentous or granular structures under erythrocyte membranes. As the membrane skeletons got closer to the marginal bands, they become more dense network structures. Moreover, in the fresh unfixed specimens, dense networks of filaments were localized underlying erythrocyte membranes in a relatively intact state. Fine filaments connected the marginal microtubule bands to the cytoplasmic sides of erythrocyte membranes. The different distribution of each cytoskeletal component and the association of these structures may support the elliptocytic shape of chicken erythrocytes and resist the dynamic circumstance.

Novel isoform of myotonin protein kinase: gene product of myotonic dystrophy is localized in the sarcoplasmic reticulum of skeletal muscle

It is quite important to know the exact localization and function of myotonin protein kinase (MtPK), identified as the gene product of myotonic dystrophy, the most prevalent disease with multisystem disorders among muscular dystrophies. To investigate the localization of MtPK, we raised a polyclonal antibody against a synthetic peptide chosen within the deduced sequence of MtPK. This antibody detected both a membrane-bound 70-kd protein and a soluble 55-kd protein on Western blots of human muscles. By using this antibody for immunohistochemical studies of both biopsied human skeletal muscle fibers and mature innervated cultured muscle fibers, we can now demonstrate by confocal laser scanning microscopy that MtPK is localized mainly in the I-band. By immunoelectron microscopy, it was determined that MtPK is a membrane-bound protein localized mainly in the terminal cisternae of the sarcoplasmic reticulum. To our knowledge, this is the first documentation of the ultrastructural localization of MtPK. This finding is quite important for clarifying the pathophysiological basis of myotonic dystrophy, which might be due to a dysregulation of calcium metabolism.

Interaction of Nck-associated protein 1 with activated GTP-binding protein Rac

Bacterially expressed glutathione S-transferase fusion proteins containing Rac1 were used to identify binding proteins of this Rho family GTPase present in a bovine brain extract. Five proteins of 85, 110, 125, 140 and 170 kDa were detected, all of which were associated exclusively with guanosine 5'-[gamma-thio]triphosphate-bound Rac1, not with GDP-bound Rac1. The 85 and 110 kDa proteins were identified as the regulatory and catalytic subunits respectively of phosphatidylinositol 3-kinase. Several lines of evidence suggested that the 125 kDa protein is identical with Nck-associated protein 1 (Nap1). The mobilities of the 125 kDa protein and Nap1 on SDS/PAGE were indistinguishable, and the 125 kDa protein was depleted from brain extract by preincubation with the Src homology 3 domain of Nck to which Nap1 binds. Furthermore, antibodies to Nap1 reacted with the 125 kDa protein. Nap1 was co-immunoprecipitated with a constitutively active form of Rac expressed in Chinese hamster ovary cells. The observation that complex formation between activated Rac and PAK, but not that between Rac and Nap1, could be reproduced in vitro with recombinant proteins indicates that the interaction of Nap1 with Rac is indirect. The 140 kDa Rac-binding protein is a potential candidate for a link that connects Nap1 to Rac. The multimolecular complex comprising Rac, Nap1 and probably the 140 kDa protein might mediate some of the biological effects transmitted by the multipotent GTPase.

A protein kinase Cdelta-binding protein SRBC whose expression is induced by serum starvation

West-Western screening of a cDNA expression library using 32P-labeled, autophosphorylated protein kinase Cdelta (PKCdelta) as a probe, led us to identify cDNA clones encoding a PKCdelta-binding protein that contains a leucine zipper-like motif in its N-terminal region and two PEST sequences in its C-terminal region. This protein shows overall sequence similarity (43.3%) to the serum deprivation response (sdr) gene product, and we named it SRBC (sdr-related gene product that binds to c-kinase). PKCdelta binds to the C-terminal half of SRBC through the regulatory domain and phosphorylates it in vitro. In COS1 cells, the phosphorylation of over-expressed SRBC is stimulated by 12-O-tetradecanoylphorbol-13-acetate and further enhanced by the over-expression of PKCdelta. The mRNA for SRBC is detected in a wide variety of cultured cell lines and tissues and is strongly induced by serum starvation. Furthermore, SRBC mRNA is induced during retinoic acid-induced differentiation of P19 cells. These results suggest that SRBC serves as a substrate and/or receptor for PKC and might be involved in the control of cell growth mediated by PKC.

A domain containing the Cdc42/Rac interactive binding (CRIB) region of p65PAK inhibits transcriptional activation and cell transformation mediated by the Ras-Rac pathway

The molecular bases of the versatile functions of Rho-like GTPases are still unknown. Using luciferase assays with rat 3Y1 cells, we found that Rac1 is integrated downstream of Ras in the TRE (TPA response element) activation pathway. Coexpression of a mutant of p65PAK, PAK/RD, lacking the kinase domain but containing the Cdc42/Rac interactive binding (CRIB) region, suppressed the TRE activation and cell transformation caused by constitutively activated forms of Ras (RasV12) and Rac1 (Rac1V12). PAK/RD is a good tool to investigate the signaling pathways in which Rac and Cdc42 are involved.

Serologic survey for HTLV-I in Kanagawa Prefecture

To investigate the seroprevalence of HTLV-I in Kanagawa Prefecture (central Japan), we tested the sera of 8,264 healthy volunteers and 2,414 pregnant women. Of the 8,264 healthy volunteers, 66 (0.80%) were seropositive. The seroprevalence of HTLV-I in the pregnant women was 14/2,414 (0.58%), and this rate was almost identical to that in the healthy female volunteers 15 to 44 years of age (0.59%). These figures indicate that the seroprevalence of HTLV-I in Kanagawa Prefecture is very low and that sexual contact may not be an important contributory factor.

Overexpression of p53 is associated with growth pattern and prognosis in advanced gastric cancer

BACKGROUND/AIMS

The growth pattern of advanced gastric carcinoma, based on volumetric analysis, is closely associated with the biological characteristics of tumors, including DNA ploidy, and is an important prognostic factor. Abnormality of the p53 tumor suppressor gene plays an important role in alteration of cells and possibly leads to cancer development.

MATERIALS AND METHODS

Expression of tumor suppressor gene p53 was investigated immunohistochemically in the primary lesion of 196 patients with advanced gastric cancers, and the relationship of p53 immunopositivity with the growth pattern and prognosis was analyzed.

RESULTS

Positive p53 staining was found in 94 (48%) of the 196 primary carcinomas. Vessel invasions were more frequent and lymph node metastasis was more extensive in p53-positive tumors (p < 0.05), whereas p53 immunopositivity was not associated with depth of cancer invasion nor with the stage of cancer. In the column and mountain type tumors, characterized by vertical or penetrative growth, positive p53 staining was found in 53.8% and 52.9%, respectively. In the funnel type tumor, characterized by superficially spreading growth, positive p53 staining was found in significantly lower incidence (28.9%, p < 0.05). The 5-year survival rates were 44.2% and 25.4% for patients with p53 negative and positive gastric carcinomas, respectively (p < 0.01). Multivariate analysis showed that p53 overexpression was an independent prognostic factor of patients with advanced gastric cancer.

CONCLUSIONS

These findings suggest that p53 gene alteration is associated with less favorable prognosis of advanced gastric cancer, possibly by providing tumors with a potential of vertical growth into the gastric wall.

Characterization of a cartilage-derived 66-kDa protein (RGD-CAP/beta ig-h3) that binds to collagen

A 66-kDa collagen fiber-associated protein (RGD-CAP) was isolated from a fiber-rich fraction of pig cartilage by ultrafiltration and collagen-affinity chromatography. Amino acid sequencing and cDNA cloning indicated that the RGD-CAP is identical or closely related to beta ig-h3 protein which is induced in human adenocarcinoma cells by transforming growth factor-beta (TGF-beta) (Skonier, J., Neubauer, M., Madisen, L., Bennett, K., Plowman, G.D., and Purchio, A.F. (1992) DNA Cell. Biol. 11, 511-522). The RGD-CAP, as well as beta ig-h3, has the RGD sequence in the C-terminal region. The native RGD-CAP bound to type I, II, and IV collagens even in the presence of 1 M NaCl. A recombinant preparation of RGD-CAP expressed in Escherichia coli cells also bound to collagen but not to gelatin. The RGD-CAP mRNA was expressed in chondrocytes throughout all stages, although the expression level was highest during the prehypertrophic stage. In addition, TGF-beta increased the RGD-CAP mRNA level in chondrocyte cultures. Since RGD-CAP transcripts were found in most tissues, this novel collagen-binding protein may play an important role in cell-collagen interactions in various tissues including developing cartilage.

Conformation-dependent activation of type II adenylyl cyclase by protein kinase C

Phorbol ester treatment enhanced the catalytic activity of type II adenylyl cyclase overexpressed in insect cells. In cells coexpressing type II adenylyl cyclase and protein kinase C-alpha, type II adenylyl cyclase catalytic activity was higher even in the absence of phorbol ester treatment; phorbol ester treatment further and markedly enhanced type II adenylyl cyclase catalytic activity. However, this enhancement, either by phorbol ester treatment or by coexpression of protein kinase C-alpha, was lost following membrane solubilization with detergents. This attenuation was unaffected by phosphatase inhibitor or salts. In contrast, membrane solubilization did not affect forskolin-stimulated type II adenylyl cyclase catalytic activity. Purified type II adenylyl cyclase was stimulated by forskolin and Gs alpha, but not by protein kinase C-alpha. Therefore, a specific mammalian protein kinase C isoenzyme can activate type II adenylyl cyclase, but the mechanism clearly differs from that underlying either Gs alpha- or forskolin-mediated stimulation.

Significance of routine annual esophagram for early detection of carcinoma of the esophagus

BACKGROUND/AIMS

In order to achieve increased survival rates for patients with carcinoma of the esophagus, early detection of the disease is vital. Serial esophagrams were evaluated to clarify which interval would be effective for early detection of carcinoma of the esophagus during routine examination.

MATERIALS AND METHODS

One hundred eighty-nine patients with carcinoma of the esophagus were grouped into three, according to the experience and the time of the previous roentgenograms before the definite diagnosis.

RESULTS

Five patients were in Group 1, in which roentgenographic examination had been done within 12 months prior to the diagnosis. Retrospective observation revealed a slight but certain abnormal shadow at the same location as the esophageal tumor seen on the second films. In Group 2, seven had received an esophagram between 12 and 24 months before the diagnosis. In contrast to Group 1, neither abnormality nor findings indicating esophageal tumors were detected on the former x-ray films, in all seven cases. Group 2 was characterized by relatively small tumors and low stage of the disease. Mean tumor length was 4.1 +/- 2.9 cm, and three of seven were classified as Stage I and two as Stage IIA. On the other hand, most of the 177 patients in Group 3, with no previous examination of the esophagus within 24 months before the diagnosis, had far advanced disease. Mean tumor length was 6.3 +/- 2.6 cm. Only nine (5.1%) were classified as Stage I, whereas 115 (65.0%) were classified as Stage III or IV.

CONCLUSION

In light of these data, for populations in which esophageal cancer frequently occurs, esophageal examination every 12 months will no doubt contribute towards the early detection of lesions.

Triplet repeat polymorphism in the transmembrane region of the MICA gene: a strong association of six GCT repetitions with Behçet disease

A member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), MICA, has been recently identified near the HLA-B gene on the short arm of human chromosome 6. The predicted amino acid sequence of the MICA chain suggests that it folds similarly to typical class I chains and may have the capacity to bind peptides or other short ligands. Therefore, MICA is predicted to have a specialized function in antigen presentation or T cell recognition. During nucleotide sequence analyses of the MICA genomic clone, we found a triplet repeat microsatellite polymorphism of (GCT/AGC)n in the transmembrane (TM) region of the MICA gene. In 68 HLA homozygous B cell lines, 5 distinct alleles of this microsatellite sequence were detected. One of them contained an additional one base insertion that created a frameshift mutation resulting in a premature termination codon in the TM region. This particular allele may encode a soluble, secreted form of the MICA molecule. In addition, we have investigated this microsatellite polymorphism in 77 Japanese patients with Behcet disease, which is known to be associated with HLA-B51. The microsatellite allele consisting of 6 repetitions of GCT/AGC was present at significantly higher frequency in the patient group (Pc = 0.00055) than in a control population. Furthermore, the (GCT/AGC)6 allele was present in all B51 positive patients and in an additional 13 B51 negative patients. These results suggest the possibility of a primary association of Behcet disease with MICA rather than HLA-B.

Structure and composition of rat precorneal tear film. A study by an in vivo cryofixation

PURPOSE

To visualize the in vivo structure and to investigate the composition of rat precorneal tear film.

METHODS

An in vivo cryofixation with freeze substitution method of electron microscopy was used for the study. For light and transmission electron microscopy, a small amount of aluminum powder was used as a tracer spread on the corneal surface. The eyeballs were immediately and quickly frozen by pouring an isopentane-propane mixture cooled by liquid nitrogen directly over the eyes. For scanning electron microscopy, the corneal surface was freeze-fractured after the cryofixation. The specimens were then freeze-substituted and prepared conventionally for microscopic observation.

RESULTS

The tear film appeared as a layer of homogeneous and fine network-like structures varying from 2 to 6 microns in thickness on the corneal surface, with a membrane-like layer covering its surface. The aluminum powder was located on the surface of the tear film. The tear film could be removed completely by applying 10% or 20% acetylcysteine, but not by phosphate buffer.

CONCLUSIONS

The in vivo structure of the rat tear film is composed primarily of mucus, with a lipid layer covering its surface but without a free aqueous layer. The "three layers theory" of tear film structure requires revisions.

Analysis of allelic variation of the TAP2 gene in sarcoidosis

Sarcoidosis is a systemic granulomatous disease and the DRB1 gene of the DR subregion has been implicated for determining the genetic susceptibility to the disease. We evaluated the allelic variation of the TAP2 gene using the PCR-RFLP method as well as the mismatched PCR-RFLP method in 82 Japanese patients with sarcoidosis and 92 healthy controls. A new allele, TAP2*0103 and a new polymorphic variation at codon 577 in addition to TAP2*0101, TAP2*0102 and TAP2*0201 have been recognized in the Japanese subjects. No significant differences were observed in the frequencies of any TAP2 alleles or dimorphism at codon 577 between the patients and healthy controls. Polymorphic variation of the TAP2 gene does not confer the susceptibility to sarcoidosis.

Magnetic resonance imaging with fluid-attenuated inversion recovery pulse sequences in MELAS syndrome

We report the brain magnetic resonance imaging findings in the case of a 5-year-old boy with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Fluid-attenuation inversion recovery (FLAIR) imaging revealed multifocal abnormal cortical signals which were difficult to see on conventional T1- and T2-weighted images. Although the patient was in an advanced clinical stage of disease and had severe cortical atrophy, FLAIR imaging demonstrated characteristic findings of MELAS.

Immunogenetic study of sympathetic ophthalmia

Sympathetic ophthalmia (SO) is very rare but it remains one of the most intractable eye diseases. In clinical manifestations and histopathologic features SO is known to resemble closely Vogt-Koyanagi-Harada's disease (VKH disease). We had reported that VKH disease was significantly associated with HLA-DRB1*04 and -DQB1*04 in Japanese patients. In this study, to investigate an HLA association with SO we performed HLA serological and PCR-based DNA typing in 16 patients and 50 healthy controls. Our study revealed that HLA-DRB1*04 (0405; Pc < 5 x 10(-4)), DQA1*03 (Pc < 5 x 10(-3)), and DQB1*04 (0401; Pc < 5 x 10(-4)) were significantly associated with SO as compared to the healthy controls but there was no significant difference in the frequencies of any DPB1 alleles between the patients and healthy controls. It can be postulated that not only the clinical manifestations but also the genetic predisposition of SO are very similar to those of VKH disease.

[Primary biliary cirrhosis (PBC)-CREST overlap syndrome complicated with Sjögren's syndrome]

We reported two sisters of primary biliary cirrhosis (PBC)-CREST overlap syndrome complicated with Sjögren's syndrome (SS). Both patients had Raynaud's phenomenon, sclerodactylia, telangiectasia, chronic sialoadenitis, chronic nonsuppurative destructive cholangitis by liver biopsy and were positive for anti-centromere antibodies. This is the first report of two sisters of PBC-CREST overlap syndrome complicated with SS.

Suppression of actively induced experimental autoimmune uveoretinitis by CD4+ T cells

BACKGROUND

Helper/inducer T cells that exert an inhibitory effect on disease induction have been recently found in many experimental models. In order to clarify the mechanisms of spontaneous remission of experimental autoimmune uveoretinitis (EAU), we investigated the inhibitory effect and the phenotype of the post-recovery suppressor cells.

METHODS

In a series of experiments, we separated spleen cells of rats that had recovered from EAU. Three groups of spleen cells, CD4+ T, CD8+ T and B cells, were each adoptively transferred into naive syngeneic rats before active immunization with retinal soluble antigen (S-Ag) and Freund's complete adjuvant or passive immunization with uveitogenic T cells from donor rats. Inflammation was examined clinically and histologically.

RESULTS

The development of EAU could be significantly prevented by adoptive transfer of CD4+ T cells, whereas CD8+ T cells could not suppress the onset. However, post-recovery CD4+ T cells failed to inhibit EAU induced by passive immunization with uveitogenic T cells.

CONCLUSION

These findings indicate that CD4+ post-recovery (suppressor) T cells may play an important role in the remission of EAU.

Ultrastructural study of axonal cytoskeletons in the optic nerve damaged by acutely elevated intraocular pressure using the quick-freezing and deep-etching technique

The aim of this study was to examine the ultrastructure of axonal cytoskeletons in guinea pig optic nerve damage induced by acutely elevated intraocular pressure (IOP) employing the quick-freezing and deep-etching method. An IOP of 60 mm Hg was maintained for 4 h. The unmyelinated axoplasm of the optic nerve at the normal IOP was filled with longitudinally oriented neurofilaments and bundled microtubules, which were cross-linked by numerous cross-bridges. Membranous organelles, such as mitochondria and vesicles, were scattered in the axoplasm. These organelles were similarly interconnected with microtubules or neurofilaments by the cross-bridges. The unmyelinated axoplasm of the optic nerve following acutely elevated IOP was shown to include intraaxonal collections of various membranous organelles and reduction of microtubules and neurofilaments. The cross-bridges linking microtubules, neurofilaments and membranous organelles in such axoplasm appeared to be dramatically reduced in number. Thus, it is suggested that the ultrastructural changes of axonal cytoskeletons in some optic nerves following elevated IOP might include the reduction of microtubules, neurofilaments and their associated cross-bridges.

The seroprevalence of HTLV-I in patients with ocular diseases, pregnant women and healthy volunteers in the Kanto district, central Japan

HTLV-I has been shown to be related to the development of inflammatory diseases in various organs such as the eyes, lungs and joints. In south-west Japan where HTLV-I is highly endemic, the term 'HTLV-I associated complex' has been approved. To investigate the seroprevalence of HTLV-I in the Kanto district in central Japan, we have estimated the frequency of seropositivity to HTLV-I in 2,110 patients with various ocular diseases and 2,683 pregnant women, in addition to 5,336 healthy volunteers. Of the healthy volunteers, only 42 (0.79%) were seropositive, and the HTLV-I seroprevalence in pregnant women was also only 16/2,683 (0.60%) which was almost equal to that in female healthy volunteers aged 15-44 years (0.59%). In patients with various ocular diseases, however, there was significantly higher seroprevalence of HTLV-I (2.32%) compared with healthy volunteers in each sex (male: p = 0.0029; female: p = 0.000023). These results suggest that the seroprevalence of HTLV-I in the Kanto district is much lower than in south-west Japan. On the other hand, HTLV-I infection was shown to be correlated to ocular diseases also in the Kanto district. In particular, we found a higher seroprevalence of HTLV-I in patients with inflammatory ocular disease, such as endogenous uveitis, episcleritis, retinitis pigmentosa and degenerative choroiditis. This possibly suggests a causative role of HTLV-I in the development of these inflammatory ocular diseases also where HTLV-I is not endemic.

Electron microscopic study of erythroblastic islands obtained by 'tissue-stamp culture' method

A new 'tissue-stamp culture' method was developed for stamping proliferating erythroblasts of mouse spleens on collagen-coated coverslips after inducing haemolytic anaemia by administration of 1-acetyl-2-phenylhydrazine, and then adherent splenic cells were cultured for a few days. We could obtain many erythroblastic islands, where cultured erythroblasts were located over macrophages and were proliferated synchronously for 10-30 h, and then the erythroblasts were differentiated and enucleated after 30-50 h in the presence of erythropoietin. To observe three-dimensional structures of the erythroblastic islands, a scanning electron microscope was used for the cultured cells treated with critical point-drying method. Immature wrinkled erythroblasts with many micropinocytic pits were attached to the central area of the flattened macrophages with many cytoplasmic projections, though matured erythroblasts were localized on their peripheral areas. Moreover, cytoplasmic projections of underlying macrophages, which were attached to the matured erythroblasts, were decreased in number. At a late stage, deep cytoplasmic invaginations of erythroblasts observed at a middle stage became shallow after their enucleation and flattened to form their concave shapes. This 'tissue-stamp culture' system would be useful for studying specific interaction between stromal macrophages and haematopoietic cells.

Ultrastructural study of glomerular capillary loops at different perfusion pressures as revealed by quick-freezing, freeze-substitution and conventional fixation methods

Wistar rat kidneys were perfused with some fixatives at different pressures of 100, 150, 200 or 250 cm H2O via the aorta and were studied by the quick-freezing and freeze-substitution (QF-FS) or deep-etching (QF-DE) methods, in addition to the conventional immersion or perfusion fixation method. Different parts of glomerular capillary walls were selected for morphometric analyses. It was demonstrated that the widths of glomerular slit diaphragms and the spaces between foot processes were more widely dilated at higher perfusion pressures (200 and 250 cm H2O) than those seen at both normal perfusion pressure (150 cm H2O) and lower perfusion pressure (100 cm H2O). On the other hand, the glomerular basement membranes were thinner at higher perfusion pressures. By the QF-FS and QF-DE methods, the foot processes showed different shapes from those revealed by the conventional preparation methods, even at the same perfusion pressure. It is concluded that the widths of glomerular slit diaphragms and glomerular basement membranes and the spaces between foot processes may be significantly changed in vivo, depending on the hemodynamics in the glomerular capillary.