A novel apoptotic cascade mediated by CDK4 in rat pheochromocytoma PC12 cells

Apoptosis induced by serum withdrawal in pheochromocytoma PC12 cells is promoted by overexpression of cyclin-dependent kinase 4 (CDK4). We compared CDK4-promoted apoptosis with that induced by serum withdrawal alone in PC12 cells. Protein synthesis inhibitors did not prevent apoptosis in parental cells, but prevented the promotion of apoptosis by CDK4 overexpression. Nerve growth factor, basic-fibroblast growth factor, and Bcl-2 proteins protected both parental and CDK4-overexpressing cells from apoptosis. However, insulin-like growth factor-I and Bcl-X(L) protein only partially inhibited apoptosis in the CDK4-overexpressing cells. Bcl-2 or Bcl-X(L) had no significant effect on CDK4 kinase activity in both cell lines. These results suggest a novel CDK4-mediated apoptotic cascade which is normally restrained, but which is activated by CDK4 overexpression. This apoptotic cascade should eventually converge with the cascade induced by serum withdrawal in normal PC12 cells. We discuss the interactions among these apoptotic cascades and the points where anti-apoptotic agents act.

Induction of differentiation of pre-NKT cells to mature Valpha14 NKT cells by granulocyte/macrophage colony-stimulating factor

Valpha14 NKT cells express an invariant antigen receptor encoded by Valpha14 and Jalpha281 gene segments as well as natural killer (NK) markers, including NK1.1. Here, we describe a precursor population of NKT cells (pre-NKT) that expresses NK1.1, T cell antigen receptor beta, pTalpha, and RAG1/2 but not Valpha14 and surface CD3epsilon. Such pre-NKT cells were differentiated successfully in vitro into mature CD3epsilon+ Valpha14(+) NKT cells by IL-15 and granulocyte/macrophage colony-stimulating factor (GM-CSF) in conjunction with stroma cells. Interestingly, only GM-CSF without stroma cells induced the Valpha14-Jalpha281 gene rearrangement in the pre-NKT cells. This also was confirmed by the findings that the number of mature Valpha14 NKT cells and the frequency of Valpha14-Jalpha281 rearrangements were decreased significantly in the mice lacking a GM-CSF receptor component, common beta-chain. These results suggest a crucial role of GM-CSF in the development of Valpha14 NKT cells in vivo.

Establishment and characterization of a novel ALL-L3 cell line (BALM-18): induction of apoptosis by anti-IgM and inhibition of apoptosis by bone marrow stroma cells

A human acute lymphoblastic leukemia (ALL) cell line, BALM-18, was established from the peripheral blood specimen of a patient with B cell ALL L3 type (ALL-L3) at diagnosis using bone marrow stroma cells (BST) as feeder cells. The primary leukemia cells did not grow without feeder cells. As with the primary leukemia cells, BALM-18 showed an immunophenotype of Burkitt's lymphoma group I [CD10+, CD20+, CD23-, CD39-, CD77+] and carried the t(8;14)(q24;q32) chromosomal abnormality which is highly associated with ALL-L3 and Burkitt's lymphoma. It also revealed a significantly low level of bcl-2 protein. Strikingly, anti-human IgM antibody did induce apoptosis in induction experiments. However, it was reversed by the addition of anti-CD40 antibody or BST cells, whereas the culture supernatant of the stroma cells did not show any effect on the inhibition of apoptosis. BALM-18 may be useful for analyzing both the mechanisms of anti-IgM induced apoptosis and signaling during the inhibition of apoptosis by CD40 or BST cells.

The human PMS2L proteins do not interact with hMLH1, a major DNA mismatch repair protein

The human PMS2 gene encodes one of the bacterial mutL homologs that is associated with hereditary nonpolyposis colorectal cancer (HNPCC). One of the interesting features of the hPMS2 gene is that it is part of a multiple gene family which is localized on chromosome bands 7p22, 7p12-p13, 7q11, and 7q22. Here we report four newly identified hPMS2-like (PMS2L) genes. All four novel members of the PMS2L gene family encode relatively short polypeptides composed of the amino-terminal portion of hPMS2 and are expressed ubiquitously except in the heart. To clarify whether the PMS2L polypeptides contribute to the DNA mismatch repair (MMR) pathway through an interaction with hMLH1, we have performed a yeast two-hybrid assay and an immunoprecipitation study using an hPMS2 mutant cell line, HEC-1-A. Our results clearly indicate that hMLH1 does not interact with two representative PMS2Ls, whereas the carboxyl-terminal portion of hPMS2, not the amino-terminal portion, does interact with hMLH1. Thus, PMS2Ls are not likely to participate in the MMR pathway through association with hMLH1; they must play some other roles in the living cells.

Differential regulation of alpha- and beta-CGRP mRNAs within oculomotor, trochlear, abducens, and trigeminal motoneurons in response to axotomy

Spinal and cranial motoneurons express alpha- and beta-calcitonin gene-related peptide (CGRP) mRNAs constitutively at variable ratios, and these two mRNAs are differentially regulated following axotomy in spinal, facial, and hypoglossal motoneurons. The purpose of this study was to investigate the change in CGRP mRNA expression following nerve injury in oculomotor, trochlear, abducens, and trigeminal motor nuclei in which beta-CGRP mRNA is predominantly expressed under normal conditions. Using male Sprague-Dawley rats, either the left eyeball and the orbital contents including the bulbar muscles were removed, or the left masseter nerve was ligated and transected. The rats were allowed to survive for 1, 3, 7, 14, 28, 56 days following these procedures. The levels of mRNAs for alpha- and beta-CGRP and growth-associated protein (GAP)-43 were analyzed by in situ hybridization histochemistry using 35S-labeled oligonucleotide probes. Following nerve injury, the expression of alpha-CGRP mRNA rapidly increased on the directly-injured side in all of these nuclei. Thereafter, it gradually decreased and returned to about the control level at postoperative day 56 within oculomotor, trochlear, and abducens motoneurons, but it sustained at a high level within trigeminal motoneurons. The expression of beta-CGRP was quite variable among these nuclei, and significant changes were also seen on the side contralateral to the directly-injured side. These data indicate that the up-regulation of alpha-CGRP mRNA may be a common response of cranial motor neurons following axotomy even if the constitutive expression of beta-CGRP mRNA exceeds that of alpha-CGRP mRNA in these neurons.

CDK4, a possible critical regulator of apoptosis in rat pheochromocytoma PC12 cells

The function of cell cycle regulator molecules during apoptosis induced by serum withdrawal was examined in rat pheochromocytoma PC12 cells. When human cDNAs encoding cyclins, cyclin-dependent kinase 2 (CDK2), CDK4, and cell-division cycle 2 (CDC2), were introduced, only CDK4-overexpressing cells were more prone to apoptosis compared with parental cells. In the parental cells, serum withdrawal resulted in the upregulation of CDK4 protein expression 6.6-fold for the first 12 h after serum withdrawal. In contrast, CDK4 protein levels in CDK4-overexpressing cells remained constant for the first 12 h followed by a gradual decline. Expression of cyclin D1 was upregulated in both cell lines. The change in CDK4 kinase activity almost paralleled that of CDK4 protein expression. These results suggest that CDK4 kinase activity is one of the critical regulators in the apoptotic cascade in PC12 cells.

Occlusal stability in Class II, Division 1, deep bite cases followed up for many years after orthodontic treatment

This case report analyzes long-term occlusal stability that can be achieved in Class II, Division 1, deep bite cases with active treatment finished during the period of maxillomandibular growth. The analysis was designed to identify occlusal features common to two cases at the end of active treatment and to study how the occlusion changed with growth and jaw movement to achieve stability. The following occlusal features were shared by the two cases at the end of active treatment: (1) AB plane and axes of the maxillary and mandibular posterior teeth were perpendicular to functional occlusal plane; (2) the axis of the lower incisor was almost perpendicular to DC-L1i line; (3) the anterior occlusion was overcorrected to or near an edge-to-edge relationship. Items 1 and 2 remained unchanged throughout the follow-up periods, regardless of growth status, and the overjet and overbite increased during maxillomandibular growth after treatment. During the period of mandibular growth alone, after the end of retention, the axes of maxillary incisors tipped labially; as a result, F line became parallel to CDM line by the end of growth. The labial tipping of maxillary incisors brought the lower incisal edge into contact with or extremely near the inflection point (Bp).1 By the end of growth, the tangent of Bp became parallel to or coincident with DC-L1i line and perpendicular to the axis of the lower incisor, and the DC-L1i lines at various times posttreatment were almost parallel to each other in the two cases. Overjet increased as the maxillary incisors tipped labially, providing proper protrusive and retrusive paths for mandibular guidance. The angle between the functional occlusal plane and CDM line stayed almost the same as at the end of active treatment in the two cases, suggesting a possible change in the angle of eminence in harmony with the functional occlusal plane. These factors apparently contributed to the long-term occlusal stability in the two cases.

[Novel function of Calcineurin--multipotential factor as protein a phosphatase]

Calcineurin, serine/threonine phosphatase2B, is well known as a target of immunophilin-immunosuppressant complex such as cyclophilin-cyclosporinA and FKBP -FK506. It has been disclosed that Calcineurin is involved in interleukin 2 gene activation pathway lead to T lymphocyte proliferation, however, its functions as a multipotential factor still remains unknown. Here we mention about a new aspect of Calcineurin-involved pathway through its direct interaction to Bcl-2, an apoptosis suppressor. This direct binding of Calcineurin to Bcl-2 results in blockage of KFAT4 nuclear import by the prevention of Calcineurin-targetted dephosphorylation of NFAT4. Moreover, the tight binding between Calcineurin and Bcl-2 facilitate Bcl-2 activation as a apoptosis inhibitor through dephosphorylation of phosphorylated form of Bcl-2 serving to apoptosis regulation.

[Successful treatment with high dose chemotherapy following peripheral blood stem cell transplantation for relapsed Burkitt's lymphoma with central nervous system involvement]

A 19-year-old man complaining of right upper abdominal pain underwent surgery for the removal of a testicular tumor in October 1997. He was given a diagnosis of Burkitt's lymphoma and was in clinical stage II B. The patient went into completed remission with VABCOP-M combination chemotherapy, but relapsed with involvement of the central nervous system (CNS). He was treated with ICE, then CHASE together with total cranial irradiation and simultaneous intrathecal MTX and cytosine arabinoside through Ommaya reservoir until a second remission was achieved. Afterward, the patient was given high-dose chemotherapy and total body irradiation followed by an autologous peripheral blood stem cell transplant (auto-PBSCT), and maintained complete remission. Though the prognosis for Burkitt's lymphoma with CNS involvement is considered to be poor, high-dose chemotherapy with PBSCT was a successful treatment for relapsed Burkitt's lymphoma in our patient.

Natural killer-like nonspecific tumor cell lysis mediated by specific ligand-activated Valpha14 NKT cells

We have recently identified alpha-galactosylceramide (alpha-GalCer) as a specific ligand for an invariant Valpha14/Vbeta8.2 T cell receptor exclusively expressed on the majority of Valpha14 NKT cells, a novel subset of lymphocytes. Here, we report that alpha-GalCer selectively activates Valpha14 NKT cells resulting in prevention of tumor metastasis. The effector mechanisms of the ligand-activated Valpha14 NKT cells seem to be mediated by natural killer (NK)-like nonspecific cytotoxicity. Indeed, the cytotoxic index obtained by alpha-GalCer-activated Valpha14 NKT cells was reduced by the addition of cold target tumor cells or by treatment with concanamycin A, which inhibits activation and secretion of perforin, but not by mAbs against molecules involved in the NKT cell recognition and conventional cytotoxicity, such as CD1d, Vbeta8, NK1. 1, Ly49C, Fas, or Fas ligand. These results suggest that the ligand-activated Valpha14 NKT cells kill tumor cells directly through a CD1d/Valpha14 T cell receptor-independent, NK-like mechanism.

The Fas antigen and Fas-mediated apoptosis in B-cell differentiation

In the B-cell lineage, Fas, a type 1 membrane protein belonging to the tumor necrosis factor receptor (TNF) family, is expressed on B-cells at a restricted developmental stage and on activated B-cells, but not on naive mature B-cells. Apoptosis mediated by Fas-Fas ligand interactions may be involved in the peripheral elimination of autoreactive B-cells and in the regulation of the immune response through deletion of B-cells activated by foreign antigens, as for the T-cell lineage. Fas-mediated apoptosis associated with B-cell activation is affected by costimulation through other accessory signaling molecules like CD40, whose ligands are on T-cells.

Comparison of two methods of staining apoptotic cells of leukemia cell lines. Terminal deoxynucleotidyl transferase and DNA polymerase I reactions

We compared two methods to stain apoptotic cells, one using terminal deoxynucleotidyl transferase (TDT), the other DNA polymerase I, using leukemia cell lines treated with anti-Fas monoclonal antibody (MAb). Both TDT and polymerase I strongly reacted with fragmented nuclei of apoptotic MOLT-16 and Jurkat cells, but only polymerase I strongly reacted with nonfragmented nuclei of early apoptotic cells. Anti-Fas MAb-treated MOLT-4 cells showed morphological changes corresponding to early apoptosis and were strongly positive for polymerase I only. MOLT-16 and Jurkat cells treated with anti-Fas MAb and inhibitors of endonuclease and poly(ADP-ribose) polymerase showed the morphology of early apoptosis but were not strongly stained by TDT. Because DNA polymerase I has nick-translation activity, it is possible that DNA polymerase I reaction is positive in early apoptotic cells by detecting single-strand DNA cleavage, which occurs before extensive oligonucleosomal DNA cleavage and late morphological changes of apoptosis in leukemia cell lines. Although TDT is widely used to stain apoptotic cells, DNA polymerase I may be more applicable in special cases of apoptosis, in which cells undergo single-strand rather than double-strand DNA breaks. However, the procedure has limitations, such as the necessity to use cell smears for comparison with the TDT reaction. (J Histochem Cytochem 46:85-90, 1998)

Specific binding of Burkholderia pseudomallei cells and their cell-surface acid phosphatase to gangliotetraosylceramide (asialo GM1) and gangliotriaosylceramide (asialo GM2)

Specific binding between bacterial cells and host tissue is an early step of the pathogenesis of infection. Burkholderia pseudomallei cells, the causative micro-organisms of melioidosis, were demonstrated to bind specifically to tissue glycolipids (asialo GM1 and asialo GM2) by solid phase binding assay on thin layer chromatograms. The detection limit was around 400 pmol of the glycolipids. Acid phosphatase purified from the culture filtrate of B. pseudomallei was tested for such binding properties, and the same results were obtained. According to our previous studies, the enzyme is a glycoprotein located on the cell surface, and hydrolysed tyrosine phosphate most actively among the substrates so far tested. The mode of binding between the enzyme and the glycolipids was analyzed by comparison of binding levels among three samples different in protein content, sugar content and specific phosphatase activities per protein and sugar residue. The results suggested the possibility of a receptor-ligand relationship between the bacterial enzyme and the host-cell glycolipids (asialo GM).

Esophageal anisakiasis accompanied by reflux esophagitis

A case with esophageal anisakiasis accompanied by reflux esophagitis is described. A 38-year-old man visited our hospital with complaints of heartburn and disturbance of food passage about seven hours after eating raw cuttlefish. The first esophagogastroscopy revealed an anisakis larva invading the squamocolumnar junction. Near the anisakis larva, a whitish exudate was demonstrated in the distal esophagus just proximal to the squamocolumnar junction. An anisakis larva was easily extracted from the esophagus by forceps. Reflux esophagitis with whitish exudative mucosal lesions and an area of linear erythema more than 5mm long were noted endoscopically 8 weeks after treatment with lansoprazole and cisapride. After six months the third endoscopic examination clarified that there was neither exudate nor erythema in the distal esophagus. Judging from the clinical course that he complained of newly experienced heartburn about seven hours after eating raw cuttlefish, and that whitish exudative mucosal lesions and an area of linear erythema did not disappear at three months after extraction of the anisakis larva. It was concluded that an anisakis larva enters the stomach first and then returns to the esophagus by gastroesophageal reflux.

CD1d-restricted and TCR-mediated activation of valpha14 NKT cells by glycosylceramides

Natural killer T (NKT) lymphocytes express an invariant T cell antigen receptor (TCR) encoded by the Valpha14 and Jalpha281 gene segments. A glycosylceramide-containing alpha-anomeric sugar with a longer fatty acyl chain (C26) and sphingosine base (C18) was identified as a ligand for this TCR. Glycosylceramide-mediated proliferative responses of Valpha14 NKT cells were abrogated by treatment with chloroquine-concanamycin A or by monoclonal antibodies against CD1d/Vbeta8, CD40/CD40L, or B7/CTLA-4/CD28, but not by interference with the function of a transporter-associated protein. Thus, this lymphocyte shares distinct recognition systems with either T or NK cells.

Requirement for Valpha14 NKT cells in IL-12-mediated rejection of tumors

A lymphocyte subpopulation, the Valpha14 natural killer T (NKT) cells, expresses both NK1.1 and a single invariant T cell receptor encoded by the Valpha14 and Jalpha281 gene segments. Mice with a deletion of the Jalpha281 gene segment were found to exclusively lack this subpopulation. The Valpha14 NKT cell-deficient mice could no longer mediate the interleukin-12 (IL-12)-induced rejection of tumors. Although the antitumor effect of IL-12 was thought to be mediated through natural killer cells and T cells, Valpha14 NKT cells were found to be an essential target of IL-12, and they mediated their cytotoxicity by an NK-like effector mechanism after activation with IL-12.

Expression of Fas ligand mRNA in germinal centres of the human tonsil

Fas ligand (FasL), a cell surface molecule belonging to the tumour necrosis family, induces apoptosis through its receptor, Fas antigen (Fas). Germinal centre B cells strongly express Fas, but the role of the Fas-FasL system in B-cell selection in the germinal centre remains unclear. In the present study, FasL mRNA in the tonsils was examined by RNA in situ hybridization. FasL mRNA was detected in the lymphocytes of both germinal centres and interfollicular areas, but much more intensively in the former. The distribution of cells strongly expressing FasL mRNA in the germinal centres was quite similar to that of CD45RO-positive T cells. Immunohistochemically, however, most of the germinal centre cells were positive for FasL. Flow cytometric analysis demonstrated that FasL-positive cells of the tonsils included not only CD3-positive/CD45RO-positive T cells, but also CD19-positive B cells. This finding therefore suggests either that germinal centre B cells can produce FasL, although the level of mRNA was equivocal, or that the soluble form of FasL may be released from FasL-positive T cells in the germinal centres and then bind to Fas-positive germinal centre B cells. Thus, the Fas-FasL system may participate in the positive selection of B cells.

Localization of laminin subunits in the central nervous system in Fukuyama congenital muscular dystrophy: an immunohistochemical investigation

We have undertaken an immunohistochemical study of laminin subunits in the central nervous system (CNS) of fetuses and patients with Fukuyama congenital muscular dystrophy (FCMD) and of controls including five fetuses. Immunoreaction product deposits with antibodies to laminin alpha 1, alpha 2, beta 1 and gamma 1, and beta-dystroglycan were detected on the surface and vessels of the CNS of controls. No staining with anti-alpha-sarcoglycan antibody was detected in the CNS. Neurons and glia did not react with any of the antibodies used. In utero expression of laminin subunits and beta-dystroglycan seemed to be lower in the cerebrum than in the spinal cord. Moreover, immunostaining for laminin alpha 2 and beta 1 tended to be weak on the fetal spinal cord surface. Expression of laminin subunits and dystrophin-associated proteins in the CNS may be modulated during development, as in the skeletal muscle. The distribution of immunoreaction product deposits was basically the same in FCMD and controls, although laminin alpha 2 and beta-dystroglycan expression appeared to be decreased in the CNS of the FCMD cases. Defects of the pial-glial barrier of the fetal brain surface have been considered the main cause of micropolygyria in FCMD, and these observations suggest that the co-localization and secondary loss of these proteins in association with the unknown product(s) of the FCMD gene might be involved in the CNS lesions of this disorder.

Early ultrastructural changes in the central nervous system in Fukuyama congenital muscular dystrophy

Electron microscopy of the central nervous system surface structure is described in two fetuses with Fukuyama congenital muscular dystrophy (FCMD). In addition to relatively large surface defects, many minute defects less than several micrometers in size associated with protrusion of glial cytoplasm were observed in the cerebrum. These findings were considered to represent early changes prior to cortical dysplasia. The basement membrane adjacent to the defects showed amorphous, wavy, or whorled configurations, and gradually disappeared. The glial cytoplasmic membrane seemed to be relatively well preserved in some areas where the basement membrane disappeared. On the other hand, both the basement membrane and cytoplasmic membrane became indistinct irregularly in areas without defects, including the spinal cord; similar lesions were found in the skeletal muscle. These observations confirm previous observations concerning defects of the pial-glial barrier of the brain surface, and may suggest the involvement of abnormal basement membrane or related structures, or both, in the genesis of the brain lesions of FCMD.

Achievement of a complete cytogenetic response with hydroxyurea in a patient with chronic myelogenous leukemia

Hydroxyurea rarely produces a complete cytogenetic remission in patients with chronic myelogenous leukemia (CML). In this report, we describe one case of the CML patient who achieved complete cytogenetic remission (no Ph chromosome in 20-25 metaphase cells) by treatment with hydroxyurea alone. By the fluorescent in situ hybridization (FISH) methodology using bcr/abl specific translocation probe, sequential bone marrow specimens from the patient showed the characteristic 9;22 translocation at a higher rate (9-10%) than the normal control range (2.49-4.88%) at the time of complete cytogenetic remission. Thus, it is suggested that FISH is a more sensitive method to detect the bcr/abl fusion gene than conventional cytogenetic analysis for the detection of minimal residual disease in CML.

Suppression of signalling through transcription factor NF-AT by interactions between calcineurin and Bcl-2

It is not known how the protein Bcl-2 inhibits cell death induced by calcium signalling and growth-factor withdrawal. Here we report that Bcl-2 forms a tight complex with calcineurin, resulting in the targeting of calcineurin to Bcl-2 sites on cytoplasmic membranes, and show that this interaction is dependent on the BH4 domain of Bcl-2. Calcineurin bound to Bcl-2 is an active phosphatase but is unable to promote the nuclear translocation of NF-AT, a transcription-factor required for induction of interleukin-2 expression, suggesting a mechanism by which Bcl-2 suppresses NF-AT activity. We also show that Bax, a pro-apoptotic member of the Bcl-2 family, interferes with interactions between calcineurin and Bcl-2. We propose that the ability of Bcl-2 to block NF-AT signalling is due to the sequestering of active calcineurin to the same domain of Bcl-2 which associates with Rad-1 (ref. 5), and that calcineurin may act in Bcl-2-regulated functions.

Expression of vasoactive intestinal polypeptide receptor mRNA and secretory regulation by vasoactive intestinal polypeptide in rat submandibular and sublingual salivary glands

Vasoactive intestinal polypeptide (VIP)-receptor mRNA was strongly expressed in the acinar cells in the submandibular gland but not in the sublingual gland. VIP-containing nerve fibres were richly distributed around acini in the submandibular gland but were rare around acini of the sublingual gland. In the submandibular gland, the chorda was stimulated at various frequencies (1-40 Hz) together with an infusion of (N-Ac-Tyr1, D-Phe2)-GRF(1-29)-NH2 (109 M), VIP antagonist, which reduced salivary flow from the submandibular gland only at high-frequency stimulation (> 20 Hz), and more markedly reduced the salivary protein concentration. When the chorda was continuously stimulated the antagonist reduced the salivary flow only during the initial 5 min. Exogenous VIP 10(-12) - 10(-8) M) infusion at the same time as chorda stimulation caused no increase in salivary flow, but the salivary protein concentration was increased in a dose-dependent manner. In the sublingual gland, neither VIP nor the VIP antagonist affected chorda-evoked salivary flow and protein concentration. Thus, endogenous VIP may play a part in the regulation of both fluid and protein secretion, especially of protein, evoked by chorda stimulation at high frequency in the submandibular gland. These phenomena occurred only in the initial phase of secretion. In the sublingual gland, it seems likely that VIP plays no part in the regulatory mechanism, at least with regard to salivary fluid secretion in the acinar cells.

Localization of molecules involved in cytokine receptor signaling in the rat trigeminal ganglion

The localization of some cytokine receptors and their downstream intracellular signaling molecules was examined in the trigeminal ganglia of rats. Among cytokine receptor components, we examined signal transduction subchain, gp130, IL-2Rgamma and IL-5Rbeta, which are common to respective groups of cytokine receptors. Most of the sensory ganglion neurons expressed gp130, but not IL-2Rgamma nor IL-5Rbeta. We further examined the localization of Janus kinase (JAK) family members which were reported to be associated with various kind of cytokine receptors and are thought to be implicated in major cytokine receptor-signaling pathways [6,9,11,13]. While JAK1 and Tyk2 were expressed in all the type of neurons, JAK2 was predominantly expressed in the small neurons. In addition, JAK3 immunoreactivity was only found in satellite cells. The present results indicate that most of neurons express gp130, and that the localization of JAK family members differs with the cell type. This also suggests that the cytokine receptor-signaling pathway may be different in neuronal and glial cells.

Pial-glial barrier abnormalities in fetuses with Fukuyama congenital muscular dystrophy

This report concerns light and electron microscopic studies on the central nervous system of a 20-week and an 18-week fetus with Fukuyama congenital muscular dystrophy (FCMD). The diagnosis of FCMD was established by prenatal molecular genetic analysis. Cerebral lesions containing neurites, subpial granular cells and glias, accompanied by cortical dysplasia were found in both cases. Small irregular defects, readily detectable by periodic acid-methenamine-silver staining or by immunohistochemical staining for S-100 protein, were observed in the cerebral surface. More severe dysplasia was evident at the areas with the larger defects. Surface defects were also observed in the cerebellum and brain stem, with brain tissue extruding into the leptomeninges. The pyramidal tract was aberrant in the pons and medulla oblongata. The spinal cord appeared normal by light microscopy. Electron microscopic examination revealed an abnormal configuration of the basement membrane and glial cytoplasmic membrane of the brain and spinal cord surfaces, including areas with no detectable defects by light microscopy. These findings suggest that abnormalities of the pial-glial barrier, especially the basement membrane and/or basement membrane-related structures, are involved in the genesis of cortical dysplasia.

Prenatal diagnosis of Fukuyama type congenital muscular dystrophy by polymorphism analysis

Fukuyama type congenital muscular dystrophy (FCMD) is an autosomal recessive disorder characterized by a combination of primary muscular dystrophy of early infantile onset and brain malformation (lissencephaly type II). The identification of the FCMD gene locus at 9q31 opened the theoretical possibility of prenatal diagnosis. The authors conducted prenatal diagnosis in two unrelated FCMD families by analysis using nine microsatellite CA-repeat polymorphic markers flanking the FCMD locus, and calculated phenotype probabilities in fetuses with a computer program, LINKAGE. The fetus in family 1 showed a 99% probability of being healthy either as a normal homozygote or a heterozygote carrier and was born without signs of FCMD. In family 2, the fetus was diagnosed to have FCMD with at least 86% probability. The parents of this family decided to terminate the pregnancy and an abortus showed brain malformations characteristic of an FCMD fetus.